Original published in D.F. Merriam, ed., 1964, Symposium on cyclic sedimentation: Kansas Geological Survey, Bulletin 169, pp. 287-380

Paleoecological Aspects of Kansas Pennsylvanian and Permian Cyclothems

by Raymond C. Moore

University of Kansas, Lawrence, Kansas

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Abstract

The recognition of more than 100 cyclothems in the Pennsylvanian and Lower Permian rock succession of Kansas, each containing a number of distinctive types of deposits and varied assemblages of organic remains, provides opportunity for paleoecological observations and interpretations which may come to be accepted as specially trustworthy. This is because repetitive occurrences of identical or near-identical sedimentary environments and biotopes can be analyzed comparatively and because sequential relationships of these environments and biotopes within the different cyclothems aid in confirming interpretations. Traceability of thin layers for long distances along outcrops--some more than 200 miles--allows study of geographic constancy of individual biotopes or departure from constancy. Approximately 20 representative ecologic communities (ecosystems) are characterized briefly and their stratigraphic occurrence is illustrated diagrammatically, though very incompletely.

Introduction

The purpose of this paper is to point out characters of Pennsylvanian and Permian cyclothems in Kansas which specially merit detailed paleoecological analysis. The characters to be discussed are not newly discovered, for most of them have been recognized since cyclic sedimentation was first described (Moore, 1929, 1930, 1931; Weller, 1930; Elias, 1934, 1937a) in parts of the Kansas Pennsylvanian-Permian rock column and a little later found to be clearly determinable in almost all parts of the succession. The dissimilar environments of deposition represented by coal beds, slabby sandstones and thin clayey limestones bearing tetrapod skeletal remains and footprints, sandy to clayey shales containing well-preserved parts of land plants, and strata characterized by assemblages of marine invertebrates were selfevident to early interpreters of the cyclothems, at least in general qualitative terms. To some extent different kinds of marine assemblages were discriminated and it was observed that structures interpreted as algal in origin seemed to be most common or essentially restricted to upper carbonate layers in very many cyclothems.

Observations during the 1930's and 1940's on several divisions of the Pennsylvanian and Permian in Kansas which were considered to display features of cyclic sedimentation were chiefly directed to discrimination of significant stratigraphic units and to determining their continuity from place to place across the state. This contributed greatly to precision in establishing correlations both within the borders of Kansas and between outcrops studied in Kansas and many geographically isolated exposures in southeastern Nebraska, northwestern Missouri, and southwestern Iowa. Areal stratigraphic work was carried in generally successful manner southward into Oklahoma, where considerable change in sedimentary facies occurs. By and large, the paleoecologic implications of different parts of the recognized cyclothems were given scant attention during this period, if not ignored. In regional perspective, eastern Kansas could be depicted reliably as a stable platform area which repeatedly was submerged shallowly by invading seas, whereas the Oklahoma-Arkansas country characterized by thick clastic deposits of Pennsylvanian and Permian age was prevailingly a wide downwarped trough.

The broad regional nature of Pennsylvanian and Permian sedimentary accumulations in the northern Midcontinent--that is, in territory north of the southern Oklahoma mountains--shows correlation with the kinds and lateral extent of biotopes which successively came to exist in different areas. In general, terrestrial environments such as typically belong to nearly flat coastal plains predominated south of the Kansas border and during much of Desmoinesian, early Missourian, and early Virgilian time within southern Kansas. Associated marine deposits tend to be local and variable, reflecting temporary submergences of parts of the plains. To the north and west, shallow seaways, each characterized by great extent of several sorts of marine environments which were developed successively, spread out again and again over the large crustal tract designated as stable platform. A remarkably even layer-cake stratigraphic record is the product of bed-on-bed sedimentation precisely balanced by regional crustal subsidence. Similar sorts of biotopes have exceptional geographic extent and one follows another in what must have been relatively very short intervals of geologic time (Moore, 1962).

Terminology

Paleoecology, which may be defined as the study of all aspects of relationships between ancient organisms--essentially those preserved as fossils--and their environment, has borrowed from ecology, concerned with present-day organisms and their environments, a number of special terms. Depending on context, these may or may not warrant modification by adding the prefix "paleo-," and many of them can be dispensed with for general purposes. If it is needful to distinguish between populations of ancient organisms growing together from accumulations of ancient organic remains possibly transported from various places of origin and merely buried together, classification of them as life assemblages (not paleobiocoenoses) and death assemblages (not paleothanatocoenoses) is adequate. Divisions of paleoecology into studies devoted to individual organisms or small groups of taxonomically defined organisms preserved as fossils (paleoautecology) and those concerned with ancient organic communities (paleosynecology) are useful in textbooks (Ager, 1963) but otherwise are little required.

In the present paper only two or three special terms, possibly not familiar to everyone, are rather commonly employed. These are (1) ecosystem, defined as any sort of ecologic community considered as a unit in relation to nonliving factors of its environment, and (2) biotope or paleo biotope, used to designate a region of unspecified size which is characterized by essentially uniform environmental conditions and by a correspondingly uniform population of animals or plants or both animals and plants. The word "paleoecosystem" is thought to be superfluous, and possibly the same is true of "paleobiotope" in discussion of Pennsylvanian and Permian biotopes. Nevertheless, in various connections paleobiotope seems preferable to biotope. I find no need for biome, defined by ecologists as a major natural region characterized by certain groups of organic communities, or its paleoecological equivalent, paleobiome.

Acknowledgments

Cordial appreciation and my thanks are expressed to Daniel F. Merriam and Theodore E. Jacques for assistance in field studies of Lower Permian (Beattie) deposits in southern Kansas and northern Oklahoma, both before and during days spent with John Imbrie and Léo F. Laporte for the same purpose in early August, 1964. Also, I am indebted to Frank M. Carpenter, of Harvard University, for help in recording fossil insects which to date have been described from the Elmo area of Dickinson County, Kansas. Likewise, I need to acknowledge work done by Norman D. Newell on Pennsylvanian (Missourian) correlation diagrams, which, though prepared many years ago, are published here for the first time. I am especially grateful to John Imbrie for supplying to me parts of the data derived from his detailed investigations of Florena Shale biostratigraphy and for allowing me to publish graphs which I have prepared based on information obtained from him. Finally, I thank Roger B. Williams for careful work done by him in drafting part or all of certain figures.

Pennsylvanian and Permian Organic Assemblages in Kansas

Kinds of Assemblages

Organic assemblages, or ecosystems, and the biotopes corresponding to them obviously are divisible into two main groups: (1) terrestrial or nonmarine, and (2) marine. The fact that some environments are neither strictly subaerial in the sense of being located on land (including river, lake, and marsh habitats, as well as those of hot dry deserts, frigid tundras, and many others) nor definitely marine, because situated below sea level in areas subject to flooding by ocean-connected salt water, embarrasses an oversimplified classification but presents no insuperable difficulties for an ecologist. For a paleoecologist, on the other hand, problems in dealing with many ancient assemblages and with many paleobiotopes recorded in sedimentary deposits may be extremely troublesome--so much so that no reasonably firm conclusions are possible. Therefore, a threefold classification of fossil assemblages and their equivalent paleobiotopes is desirable in paleoecologic studies: (1) definitely nonmarine, (2) definitely marine, and (3) intermediate or doubtful, the last-mentioned group including some in which paleontological and sedimentological evidence, combined with that furnished by stratigraphic relations, is deficient or possibly conflicting. Not many paleobiotopes can be treated as "cut and dried."

Generalized litho- and biostratigraphic attributes of Pennsylvanian and Permian cyclothems found in the Kansas region are illustrated in Figure 1, which also indicates alternative methods of drawing the boundaries of these cyclic sedimentary units. The stratigraphic section here given is accompanied by indication of roughly classified nonmarine and marine biotopes and interpretation of environments represented by the successive strata is marked by fluctuating position of a sedimentation-time line which shifts back and forth from column to column denoting different biotopes. The positions of some ecosystems, described in later parts of this paper, with explanation of symbols for them used on diagrams, are shown along the left margin of the diagram.

Figure 1--Diagrammatic section of successive cyclothems showing typical litho- and biostratigraphic features, accompanied by interpretation of changes in environments with lapse of time (graph at right). Alternative choices in defining boundaries of cyclothems are indicated by capital letters enclosed in parentheses: (A), (B), (C), boundaries drawn on top of coal beds, coinciding with change from nonmarine to marine conditions of sedimentation; (X), (Y), (Z), boundaries drawn at disconformities. Several sorts of ecologic communities (ecosystems) are indicated by letters along the left margin of the figure, which refer to subsequently described organic assemblages named from selected stratigraphic units in which they are typically developed and from some genus or genera which are distinctive or common constituents. [Explanation of symbols for ecosystems: "B," Beil-type (Pulchratia), "D," Drum-type (Euconospira), "M," Morrill-type (Osagia), "S," Speiser-type (Derbyia), "DN," Doniphan-type (Rhombopora), "ST," Stranger-type (Asterotheca), "T," Tarkio-type (Triticites).]

Areal Distribution of Assemblages

It is desirable at this point to make note of geographic spread of recognized organic assemblages and paleobiotopes in typical cyclothems of the Pennsylvanian and Permian succession in the Kansas region. A few of these are confined to small areas, being evidently very local, though they may be duplicated at approximately the same horizon in many other places. The great majority of distinguished biotopes, however, are extraordinarily extensive, being traceable without appreciable change for scores of miles along outcrops and some being identifiable far down dip in the subsurface. Many deposits only 10 to 20 inches in average thickness or less than 10 inches in maximum observed thickness have been identified in closely spaced outcrops extending from counties in southeastern Nebraska all of the way to northern Oklahoma, and throughout this distance essential uniformity of physical and organic features is maintained. Continuity and regularity are the rule, not the exception. This is surprising enough in a sequence of marine deposits, for in almost any seaway depth of water and the nature of bottom sediment may be expected to vary appreciably, and in company with such variation, communities of bottom-dwelling organisms should display rather easily detectable differences. Some stratigraphic observations accord with these expectations but very commonly they do not. All Kansas coal beds known to me are inferred to have been formed in a nonmarine environment, although many of them may represent plant accumulations in swamps barely beyond the reach of flooding by seemingly tideless inland seas. Some such coals have maximum known distribution of a few hundreds or thousands of square miles, and some thin beds (less than 6 inches in average thickness) are seemingly continuous along the outcrop for airline distances of 200 miles or more.

The demonstrated great areal distribution of very many, if not all paleobiotopes characteristic of Kansas Pennsylvanian and Permian cyclothems, points to exceptionlly widespread, nearly uniform environments during each episode of sedimentation, and though the nature of these environments underwent changes with lapse of time, such changes seem to have been introduced almost simultaneously everywhere. An important deduction that rests on this great geographic spread of successive paleobiotopes and their prevailing uniformity from place to place while they persisted is general stability of the underlying crust. The Kansas region thus is distinguished as having the character of a broad, relatively very stable platform.

Repetitive Occurrences of Assemblages

Inherent in concepts of cyclic sedimentation is repetition of various kinds of sedimentation in constant order as recorded at any locality. The changes in environments with lapse of time eventually introduced again and again a particular kind of biotope at places where they had existed before. This is illustrated diagrammatically in numerous sections of Pennsylvanian and Permian rocks published in the present paper, in addition to being well shown in other contributions.

The purpose of writing about repetition of paleobiotopes and various kinds of organic communities in Kansas is to point out the value of classifying them in types which seem to have similar characters and then of comparing the examples of each with one another. Critical analysis which is likely to be enhanced by a multiple attack on problems of interpreting the significance of physical, chemical, and biological attributes of the deposits which comprise records of the different environments, tabulating all observable similarities or identities on one hand and dissimilarities on the other, is best suited to yield trustworthy conclusions. Also, it is a most promising method for the development of paleoecologic principles having much practical value. For example, the cyclic relationships of associated paleobiotopes, when considered in the light of their regional stratigraphic setting, may be a surer guide to correctness in understanding than can be found in seeking modern ecologic equivalents of each observed biotope. Indeed, modern equivalents of certain Pennsylvanian and Permian paleobiotopes may occur nowhere.

Stratigraphic Definition of Assemblages

Absolutely indispensable for paleoecological studies of regional scope, applicable to areas larger than single localities of small extent, is a firmly established stratigraphic framework, and the value of this framework is enhanced in proportion to details of its content and its reliability. Most Pennsylvanian and Permian deposits found in Kansas so well satisfy the most rigorous requirements of stratigraphic correlations that they furnish one of the best field laboratories in the whole world for making useful paleoecological observations and for developing principles for practical application to other deposits. Numerous figures given in this paper illustrate parts of this stratigraphic framework.

Representative Selection of Assemblages

The remainder of this paper is devoted to the characterization of examples of organic assemblages found recurrently in parts of Pennsylvanian and Permian cyclothems of the Kansas region. Each such assemblage, or ecosystem, is indicative of a paleobiotope, some of which differ markedly from all others and some only slightly, even though distinctions among the latter are thought to be significant. Paleontological differences that reflect evolutionary changes and probably also the effects of emigrations and immigrations are intentionally ignored, because interest is centered on the complexion of animals and plants found together as a community in various ecologic conditions.

The almost endless distinguishable organic associations found preserved as fossil groups in Pennsylvanian and Permian rocks of Kansas bring to paleoecologists difficult problems of classifying and designating them, quite apart from the still more difficult problems of interpreting them in trustworthy manner. Reference to successive assemblages in parts of typical cyclothems in such terms as "molluscan faunas," "mixed faunas," "brachiopod faunas," "fusulinid faunas," as by Moore (1936a, p. 22) and Elias (1937a, p. 410) is far from definitive, and two decades later designations such as "molluscoid," "pectinoid" (Lane, 1958, p. 158), "Osagia facies," "shelly facies," "fusuline facies" (Imbrie, Laporte, and Merriam, 1959, p. 73; Laporte, 1962, p. 526), "black shale facies," "algal limestone facies" (McCrone, 1963, p. 65-66) are little if any better. Brachiopods, bryozoans, mollusks, and algae--not mentioning other organisms--are numerous both in kinds and in their ecological associations. Any assemblage of calcareous-shelled invertebrates, including fusulinid foraminifers, is "shelly." Remembering complexities of vertical and lateral variations in organic groups preserved as fossils and changes in both generic and specific composition of seemingly homologous populations with lapse of geologic time, how may we proceed in trying to make useful paleoecological discriminations? Possibly the method of choosing specified samples as types may serve to allow more precise delineation of significant characters and to provide a better basis for recording similarities or contrasts observed when various natural assemblages are compared with the selected types. I have decided to adopt this procedure in the present paper, partly as a general test of its practicability and partly to invite others to suggest any additions and improvements which are considered desirable.

Among many ecological assemblages (surely dozens) that seem worthy of recognition in fossil-bearing strata of the Kansas Pennsylvanian-Permian section approximately 20 are described in this paper at least very briefly and examples of their occurrence are indicated on accompanying stratigraphic diagrams. They are named from a selected stratigraphic unit and one or more of its contained genera in the chosen occurrence of each assemblage considered to be typical, ignoring the facts that the adopted name-giving genera commonly are present in other ecological communities and that they may be lacking in some rock units classed as representing the assemblage. For instance, Triticites is extremely abundant in the local ecosystem (Tarkio) chosen as type of the Triticites assemblage, and very few other organisms are associated with it there. It happens, however, that Triticites occurs also in a half-dozen other, differently named assemblages, and it is unknown, for example, in the upper Cottonwood Limestone, which is cited as an excellent so-called Triticites assemblage. This serves to illustrate the point that (in usage of the present paper) the adopted name of each ecosystem is merely a nomenclatural handle, which mayor may not signify what it seems to mean concerning occurrence of the name-giving genus.

Symbols for ecologic assemblages given on stratigraphic diagrams are capital letters enclosed by quotation marks. These are initial letters of rock units selected as the type exampIes in occurrence of the assemblage, thus tying it to a particular horizon and generally a specified locality. The index letter (s) is not derived from the name-giving genus of the assemblage (e.g., "B" here refers to the populous and highly varied ecosystem called Pulchratia assemblage found typically developed in the Beil Limestone Member of the Lecompton Limestone near Lecompton, Kansas). The letter symbols adopted for some assemblages, however, may be initial letters of both the selected stratigraphic unit indicated as showing type occurrence and the name-giving genus (e.g., "T" for Tarkio Limestone containing the Triticites assemblage). Several assemblages are indicated by symbols along the left margin of Figure 1.

The following descriptions of ecologic assemblages are brief--perhaps too brief. They are aimed at pointing out main distinguishing features, with little discussion generally of their paleoecological significance.

Examination of the characters of generalized simple cyclothems may be followed by calling attention to what seem to be repeated groups of more or less dissimilar cyclothems arranged in constant vertical succession. Such groups, which have been called megacyclothems (Moore, 1936a, p. 29), were first distinguished in the Shawnee part of the Virgilian Stage of the Kansas Upper Pennsylvanian and later recognized (with some undeveloped elements) in the Missourian and upper Desmoinesian successions (Fig. 2). Still later (Moore and Merriam, 1959, p. 28; Merriam, 1963; p. 105) megacyclothems have come to be delineated in the Lower Permian part of the Kansas column (Fig. 3). The distribution of various kinds of paleobiotopes in megacyclic sequences is a subject which has not yet been studied critically. This needs to be done, for seemingly it is essential to solving the origin of megacyclothems.

Figure 2--Cyclothems grouped in megacyclothems, as observed in late Missourian and early Virgilian deposits of central Kansas. Diagram emphasizes repetition of strikingly dissimilar cyclothems in constant sequence. (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 3--Cyclothems and megacyclothems in Lower Permian rock successIon of Kansas. Upper sections are accompanied by graphic representation of inferred marine transgressions (culminating phases indicated by parts of curve reaching farthest left) interrupted by sea withdrawls when sedimentation of terrestrial type prevailed (modified from Elias by notation of inferred megacyclothems, A-F). Lower part, of diagram shows correlation of cyclothem elements belonging to megacyclothems A-F (Moore in Moore and Merriam). [Included in the Acrobat PDF file of figures for this article.]

Examples of Nonmarine Assemblages

Stranger-type (Asterophyllites) Assemblage

All sorts of lands plants are here grouped arbitrarily together under the designation of Asterophyllites assemblage (Suppl. Fig. 1, 1), without making effort to separate groups of swamp-dwelling hydrophytes, dry-climate xerophytes, and intermediate plants classed as mesophytes. Instead, ferns, pteridosperms, sphenophylls, calamites, lycopods, cordaites, and coniferlike plants are lumped together, because the paleoecologic significance attached to them in this consideration of cyclothems is as markers of nonmarine environments. The name Asterophyllites assemblage is taken from the comparatively rich, well-preserved land flora which has been collected from the Stranger Formation (Tonganoxie Member) at localities 3.5 miles southeast of Lawrence (Haverkampf farm) and 5 miles northeast of Baldwin (Holcomb farm). Plants from these beds, first described by Sellards (1908a), recently have been reviewed by Cridland, Morris, and Baxter (1963) for the purpose of confirming identifications and making comparisons with Carboniferous plant-bearing beds elsewhere in North America and Europe. The symbol "ST" (from Stranger-Tonganoxie) is adopted for use on diagrams. Associated with Asterophyllites are various species of Alethopteris, Aphlebia, Annularia, Asterotheca, Cordaites, Cordianthus, Cyclopteris, Mariopteris, Neuropteris, Odontopteris, Pecopteris, Ptychocarpus, Sphenophyllum, Sphenopteris, and Spiropteris (Suppl. Fig. 1, 1-7).

In aggregate a rather rich flora of land plants has been made known from the Kansas region, and counting Cherokee cyclothems, it is noteworthy that described plants come from not less than 40 horizons in Pennsylvanian and Permian deposits, with widely distributed marine strata intercalated between nearly all successive land-plant beds. The plant fossils, including many well-preserved delicate fronds of ferns and similar remains, indicate deposition in lakes, lagoons, swamps, and waters of sluggish streams.

Animals associated with the type Asterophyllites assemblage near Lawrence comprise a cockroach fauna described by Sellards (1908b) which includes 19 species referred to eight genera. Specimens have been collected subsequent to the work of Sellards but no systematic study of them has been made.

A pictorial reconstruction of the so-called Asterophyllites assemblage, representing an example belonging near the top of the Lawrence Shale at Lawrence, Kansas, is given in Figure 4. Paleobiotopes immediately following this one in the same area are illustrated in Figures 5 and 6.

Figure 4--Restoration of Stranger-type (Asterophyllites) ecosystem associated with coal-forming conditions near end of Lawrence Shale deposition, view looking west from site of Douglas County courthouse in Lawrence, Kansas (Moore).

Figure 5--Restoration of paleobiotope introduced by marine flooding of coal swamp illustrated in Figure 4, with same location and direction of view (Moore).

Figure 6--Seascape at Lawrence, Kansas, in early Oread time, defective as a paleoecologic illustration in that depth of water, nature of salinity, and type of bottom sediment cannot be shown (J. W. Koenig).

Land Vertebrate Assemblages

Skeletal remains and tracks of tetrapods are too uncommon in Pennsylvanian and Permian strata of Kansas to warrant more than brief notice as paleoecological indicators. At most they are highly sporadic, have only local significance, and few fossils of this sort are well enough recorded to allow determination of their relation to cyclothems. An exception is the comparatively rich find of land vertebrates in shaly upper Stanton beds near Garnett, in Anderson County, and this is discussed in a later part of the paper under the designation "Rock Lake-type (Garnettius) assemblage."

Another consists of some well-marked tracks in upper Howard layers near Osage City south of Topeka, identified (Schoewe, 1956) as belonging to the Utopia Limestone Member; these have been described as belonging to amphibians (Limnopus vagus, L. littoralis, Nanopus caudatus) and a small reptile (Dromopus agilis) with tendency toward bipedal locomotion (Marsh, 1894; Baird, 1952). The presence of raindrop impressions associated with some of the tracks is of interest.

Tracks probably made by amphibians (Crucipes parvus, Collettosaurus missouriensis) in platy sandy shale of the Kansas City Group (precise horizon and locality unknown) have been reported by Branson and Mehl (1932).

A single three-toed birdlike footprint with well-defined, relatively long heel, strikingly similar to Triassic dinosaur tracks of the Connecticut Valley, was found many years ago near the Pennsylvanian-Permian boundary at a locality 2 miles northwest of Eureka, in Greenwood County. The print, approximately 6 inches long and nearly 5 inches wide, was described and figured by Moodie (1913), who gave it no name but guessed that the existence of a Kansas Permian dinosaur is within the realm of possibility.

Skeletal remains of amphibians identified as Cricotus and Eryops have been found in Lower Permian rocks of Cowley County, near the Oklahoma boundary, and bones of the pelycosaur reptile Dimetrodon in approximately equivalent beds just south of the state line (Lane, 1946). Also, Lower Permian strata of Washington County, adjoining Nebraska, have yielded remains of another amphibian named Erpetosuchus (Lane, 1946), and a new genus of trimerorhachoid amphibians named Acroplous has been described from upper Council Grove strata (Speiser Shale) in Riley County, Kansas (Hotton, 1959).

Finally, mention may be made of presumed tracks of a giant amphibian (Martin, 1922) in the Tonganoxie Sandstone (lower Virgilian) a few miles southeast of Lawrence. The animal inferred from the tracks was named Oncychopus gigas (= Wakarusopus gigas Moodie, 1931), but the marks, real enough in themselves, now are judged to be calamite stump holes and not vertebrate tracks at all (Baird, 1963).

Rock Lake-type (Garnettius) Assemblage

A paleobiotope of unusual interest is represented by closely studied deposits found in the upper part of the Stanton Formation of late Missourian age (early Late Pennsylvanian) approximately six miles northwest of Garnett, in sec. 32, T. 19 S., R. 19 E., Anderson County, Kansas. It comprises part of a cyclothem which lies disconformably on well-bedded marine limestone (Stoner Member of the Stanton) and reflects an environment interpreted as that of a somewhat brackish-water lagoon, neither typically marine nor terrestrial, for organic remains collected from its layers are a mixture of invertebrates normally confined to saline seaways and well-preserved land plants, air-breathing arthropods, riveror lagoon-dwelling coelacanth fishes, amphibians, and reptiles of cursorial and possibly semiarboreal types. This ecosystem is here termed the Garnettius assemblage, named from a distinctive scorpion originally described as Mazonia, hungerfordi Elias (in Moore, Elias, and Newell, 1936, p. 12; also, Elias, 1937b). The stratigraphic position of the unique assemblage is marked on Figure 7 by the symbol "RL" (denoting the Rock Lake Shale Member of the Stanton Limestone).

Figure 7--Correlated sections of Lansing Group (upper Missourian) in northeastern Kansas showing stratigraphic occurrence of Rock Lake (Garnettius ecosystem ("RL"), also example of Heebner-type (Listracanthus) paleobiotope (Moore, sections measured by N.D. Newell). [Included in the Acrobat PDF file of figures for this article.]

The Garnettius assemblage is comparable to the famous Burgess fauna from the Middle Cambrian of British Columbia in furnishing a glimpse of associated Paleozoic organisms unmatched by any other like community. Yet our knowledge of it obviously depends on the fortunate circumstances of exposure of a part of the deposits and the "accident" of discovery by N. D. Newell in the course of field work for the Kansas Geological Survey in 1931. If the strata and their contained fossils had been concealed by cover or if the outcrops had been unnoticed and unexplored, the Garnettius assemblage now would be as much unknown as scores of possible similar occurrences in older, age-equivalent, and younger Pennsylvanian and Permian deposits of the Kansas region.

Fossils of the South Bend Limestone Member of the Stanton at the locality northwest of Garnett are not included in the Garnettius assemblage, although they belong to the same cyclothem as that which here begins with the shaly strata (Rock Lake) containing the Garnettius community. The South Bend fauna is typically marine; it includes the fusulinid Triticites in addition to brachiopods, bryozoans, bivalves, gastropods, corals, and crinoid and echinoid remains.

Among marine invertebrates of the Garnettius assemblage are: (1) corals (?Lophophyllidium), (2) columnals of crinoids, (3) brachiopods (Lingula, Composita), (4) bryozoans (Fenestrellina, Polypora, Rhombopora), and (5) bivalves (Myalina, Yoldia, Sedgwickia) . Evidence found in ecosystems of other cyclothems suggests that all of these invertebrates except the corals are euryhaline forms, tolerant of considerable variation in salinity of waters around them, and they are interpreted to have been at home in a near-shore environment. They could have inhabited a shallow bay or lagoon having more or less restricted connection with an adjacent open shallow sea. Lingula (Suppl. Fig. 1, 8) is a burrowing inarticulate brachiopod which can survive in moderately brackish or even fresh water for brief periods of time by retreating to the deepest part of its burrow and tightly closing its shell. The genus may occur in the dark muds of tidal flats, whereas no brachiopods, including Lingula, are adapted for life in distinctly low-salinity environments.

Remains of land plants, which are a relatively abundant constituent of the Garnettius assemblage, surely were transported to the places where they became buried, as demonstrated by their association with marine organisms. A majority of the fossils are exceptionally well preserved, however. Genera (some illustrated in Suppl. Fig. 1) which have been identified are as follows, number of recognized species being indicated by accompanying numerals: Alethopteris (2), Annularia (1), Callipteridium (1), Cordaites (2), Desmopteris (2), Dichophyllum (2), ?Dicranophyllum (2), ?Lecrosia (1), ?Lepidophyllum (1), Neuropteris (2), Odontoperis (2), Palaeophycus (2), Pecopteris (1), Pteridospermostrobus (1), Samaropsis (4), Sphenopteris (3), Taeniopteris (4), ?Ulmania (1), Voltzia (1), and Walchia (4). Although hydrophytic and mesophytic types of ferns, pteridosperms, horsetails, lycopods, and sphenophylls are found in this flora, it is dominated by gymnosperms, especially the coniferlike Walchia, which denote a dry environment classifiable as xerophytic. Well-preserved specimens of coniferophyte wood from the Garnett area also have been described (Baxter and Hartman, 1954). This character and the presence of such plants as Taeniopteris, Dichophyllum, and Dicranophyllum so much resemble Permian floral assemblages that David White, a widely experienced paleobotanist of the U. S. Geological Survey, failed to see how the deposits near Garnett could be older than Permian (Moore, Elias, and Newell, 1936, p. 2, 12). In fact, they belong approximately 1,100 feet below the Pennsylvanian-Permian boundary as drawn in Kansas.

The terrestrial arthropods of the Garnettius assemblage include one genus of chelicerates, the scorpion Garnettius (Petrunkevitch, 1953, p. 34), and four genera of insects--the cockroaches Phyloblatta and Mylacris, and megasecopterans named Euchoroptera and Parabrodia (Carpenter, 1934, 1940). The megasecopterans are medium-sized to large insects with four subequal outspread wings, small head, and relatively slender, long abdomen. The cockroaches were chiefly cursorial on land but all of the Garnett insects could fly; they may have been air-borne to places where they dropped into waters of the Garnettius biotope or, more likely, their remains were transported by sluggish streams to the shallow bay or lagoon in bottom sediment of which they became buried.

Special interest relates to finds of vertebrates in the Garnettius-bearing deposits. These include coelacanth fishes (Hibbard, 1934), an amphibian named Hesperoherpeton garnettense (Peabody, 1958) which represents a new order named Plesiopoda (Eaton and Stewart, 1960) and four kinds of reptiles, the most important of which, represented by nearly complete skeletons and parts of skeletons, is a long-toed lizardlike form called Petrolacosaurus kansensis (Fig. 8), approximately 24 inches in length at maturity (Lane, 1945; Peabody, 1952). The other reptiles are all pelycosaurs, characterized by elongation of their vertebral neural spines to make a tall fin running along the middle of the back; one has been described as Edaphosarus ecordi (Peabody, 1957) and the others are an ophiacodont allied to Clepsydrops and a primitive sphenacodont. The fishes and amphibian probably lived in a stream or streams that emptied into the Garnett lagoonlike water body but the reptiles were animals of dry land. Peabody's (1952, p. 38) interpretation of the environment is worthy of quotation; with some omissions this is as follows.

Terrestrial and fluviatile organisms were rafted by a slow-running river into a marginal embayment or lagoon protected by a barrier sand bar. Calcareous mud, mainly transported by the river, was deposited in thin, possibly cyclic layers on the eroded surface of a marine limestone. The lagoon was deep enough so that waves did not disturb the bottom and the barrier bar was complete enough to exclude strong marine currents. Under these conditions, thin-bedded mud devoid of ripple marks or scour marks accumulated and formed what is now approximately 10 feet of fossiliferous shale. Deposition of mud served to impoverish the marine invertebrate fauna and exclude scavenging forms, while simultaneously preserving the remains of indigenous marine invertebrates and rafted terrestrial organisms. Rafted material became waterlogged, probably during transport, and some maceration occurred, for quantities of detached needles of conifers literally blacken some of the bedding planes. Corpses of reptiles came to rest on the mud bottom and became partly embedded. Before complete burial, differential decay weakened exposed parts. For example, the immature delicate skull rested thus dorsal side up. Most of the roof of the delicate skull then became detached and drifted away probably with the strengthened current which deposited the next layer of mud. Parts of the roof remained, because they were locked in place by the deeply embedded lower jaws and palate. . . . It is reasonable to assume that the plants, arthropods and reptiles may have been transported from one and the same terrestrial environment and at the same time by relatively quiescent but perhaps flooding waters of a Pennsylvanian river. . . . The river flowed through a relatively dry landscape dominated by conifers. Completeness of the reptilian skeletons and isolated limbs, the presence of delicate winged insects, and of fruits of conifer and pteridosperm suggest a common place of origin and one that was not far away. . . . Association of Petrolacosaurus with conifers raises the possibility of arboreal habits; elongate digits and lightened structure of the bones are suggestive of climbing ability. . . . Petrolacosaurus was an agile terrestrial reptile.

Figure 8--Restoration of part of the Garnettius ecosystem showing especially lizardlike reptile, Petrolacosaurus, approximately two feet long, and in central foreground scorpion, Garnettius. (Moore, after Peabody, 1952, painting by Victor Hogg).

Elmo-type (Sellardsia) Assemblage

Attention given to the Garnettius assemblage in this paper makes a very adequate excuse, if one is needed, for notice of another nonmarine assemblage which has been described from the famous insect-bearing deposits in the Wellington Shale near Elmo, in southern Dickinson County, Kansas, even though these are not defined as part of a recognized cyclothem. Obviously, they signify a paleobiotope which is closely comparable to that of upper Stanton beds near Garnett, though doubtless located in a prevailingly dryer climatic setting. Here, approximately 1,000 feet above the Pennsylvanian-Permian boundary, again are found marine invertebrates associated with a varied land-plant flora and a host of terrestrial arthropods, mostly insects but including aquatic chelicerates related distantly to the modern kingcrabs (Limulus). Richness of the insect fauna is indicated by published records of 7,000 or more specimens collected from the Elmo locality.

The ecologic community (ecosystem) of the Wellington in the Elmo area is designated as the Sellardsia assemblage, despite the fact that Sellardsia is a nominal genus of relatively unimportant insects and that it is considered (Carpenter, 1935, p. 129) to be a junior synonym of Lecorium Sellards (1909, p. 167). Choice of Sellardsia in this connection is dictated by the wish to honor the paleontologist who in 1902 discovered the fossil plants and insects near Elmo. After completing undergraduate and early graduate studies at The University of Kansas, Sellards was then working on his doctorate at Yale University. During the summers of 1902 and 1903 he collected some 2,000 specimens (Sellards, 1903) and subsequently described many of them (Sellards, 1906, 1907, 1909). Later, extensive collecting by Dunbar (1924, p. 173), and Carpenter (1930, p. 70; 1933, p. 411; 1939, p. 29) furnished materials for a long series of papers by Tillyard (1923-1937) and by Carpenter (1930-1950).

The invertebrates of the Sellardsia assemblage come from an evenly bedded impure limestone, 4 or 5 feet thick, mostly near the base. Locally abundant in the lowermost bed of the limestone are shells of a small bivalve identified as belonging to the marine genus Myalina, but unusually thin-shelled and interpreted, partly on this account, as abnormal, being migrants into a brackish-water habitat (Dunbar, 1924, p. 201). Nearly black shale just below the limestone contains silicified stumps and some logs of lycopods, probably Cordaites, and beneath this layer is interbedded gray shale and thin limestone. A comparatively large flora of well-preserved ferns, lycopods, horsetails, and conifers has been described from the shale. The calcareous beds have yielded minute pelecypods, conchostracans, and two kinds of merostome chelicerates. Remains of one small merostome have been described under the name Eurypterus (Anthraconectes) sellardsi (Dunbar, 1924, p. 199); these occur in association with specimens of a small limulid (Paleolimulus avitus Dunbar, 1923, Suppl. Fig. 1, 9). The plants and animals found below the insect.bearing limestone are not included in the Sellardsia assemblage.

In view of the exceptional paleontological importance of the Lower Permian insect fauna described from the Elmo, Kansas, area I have undertaken to survey its presently determined taxonomic content in terms of genera, where possible recording junior synonyms in square brackets and number of assigned species, if greater than one, by numerals enclosed in parentheses. I am grateful to Professor Frank M. Carpenter, of Harvard University, for corrections and other help in preparing the list, which is organized by orders recognized by him in the Treatise on Invertebrate Paleontology. Classification of Permian fossil insects now adopted by Carpenter differs materially from that earlier published by Brues, Melander, and Carpenter (1954) in their comprehensive survey of all living and fossil insect orders.

Lower Permian Insect Fauna from Elmo, Kansas
Palaeodictyoptera. Generalized four-winged insects with main veins of wings usually independent, beak commonly adapted for feeding on liquid foods, legs and abdominal segments unspecialized. U. Carb.-Perm.
	Calvertiella Tillyard, 1925
	Permoneura Carpenter, 1931
	Dunbaria Tillyard, 1924
	Kansasia Tillyard, 1937
Megasecoptera. Insects with four subequal wings having all main longitudinal veins in alternating ridges and furrows, mostly with well-developed cross veins rather than irregular network (archedictyon). U. Carb.-Perm.
	Protohymen Tillyard, 1924 (3) [= Pseudohymen Martynov, 1932; Pseudohymenopsis Zalessky, 1956 ]
	Permohymen Tillyard, 1924
Diaphanopterodea. Like Megasecoptera but with wings held backward along abdomen when at rest. U. Carb.-U. Perm.
	Elmoa Tillyard, 1937
	Martynovia Tillyard, 1932 [= Martynoviella Tillyard, 1932]
Ephemeroptera. Wings with all main veins, very delicate; head with large compound eyes; abdomen slender (mayflies). U. Carb.-Rec.
	Protereisma Sellards, 1907 (5) [= Protechma, Prodromus, Bantiska, Recter, Pinctodia, Esca Sellards, 1907; Mecus Sellards, 1909; Loxophlebia Martynov, 1928]
	Misthodotes Sellards, 1909 (3)
	Eudoter Tillyard, 1932
Protodonata. Medium-sized to very large insects (some with 30-inch wing spread), with globose head and long slender abdomen (early dragonflies). U. Carb.-Perm.
	Meganeuropsis Carpenter, 1939
	Megatypus Tillyard, 1925 (2)
	Tupus Sellards, 1906 (3) [= Meganeurula Handlirsch, 1906; Gilsonia Meunier, 1908; Typus Sellards, 1909; Meganeurina Handlirseh, 1919; Arctotypus Martynov, 1932]
	Oligotypus Carpenter, 1931
Odonata. Predaceous insects with four subequal wings, large compound eyes, and long slender abdomen (dragonflies). L. Perm.-Rec.
	Ditaxineura TiIIyard, 1926
	Kennedya TiIIyard, 1925
	Progoneura Carpenter, 1931
	Camptotaxineura TiIIyard, 1937
Protorthoptera. Four-winged, much as in some Palaeodictyoptera but lacking complete alternations of ridges and furrows along main veins, small head with prominent antennae, legs mostly adapted for running. U. Carb.-Trias.
	Pursa Sellards, 1909
	Sindon Sellards, 1909
	Lemmatophora Sellards, 1909
	Artinska Sellards, 1909 (3) [= Estadia, Lectrum, Orta Sellards, 1909]
	Lecorium Sellards, 1909 [= Stemma Sellards, 1909; Sellardsia Tillyard, 1928; Paralecorium, Metalecorium Handlirsch, 1937]
	Lisca Sellards, 1909
	Paraprisca Handlirsch, 1919 (2) [= Prisca Sellards, 1909 (non Fritsch, 1899)]
	Liomopterum Sellards, 1909 [= Horates Sellards, 1909]
	Semopterum Carpenter, 1950
	Tapopterum Carpenter, 1950
	Phenopterum Carpenter, 1950
	Probnis Sellards, 1909 [= Espira, Stoichus, Stinus Sellards, 1909]
	Chelopterum Carpenter, 1950
	Demopterum Carpenter, 1950
Orthoptera. Includes suborder Blattaria, cockroaches. U. Carb.-Rec.
	Etoblattina Scudder, 1879 (3)
	Puknoblattina Sellards, 1908 (2) [= Pycnoblattina TiIIyard, 1937]
	Permoblattina Tillyard, 1937
	Promartynovia TiIIyard, 1937
Caloneurodea. Like Protorthoptera except for close similarity of fore and hind wings in form, venation, and texture. U. Carb.-Perm.
	Anomalogramma Carpenter, 1943
	Paleuthygramma Martynov, 1930
	Apsidoneura Carpenter, 1943
	Permobiella TiIIyard, 1937
	Pleisiogramma Carpenter, 1943 (2)
Protelytroptera. Small insects related to cockroaches, eyes conspicuous and antennae prominent, fore wings developed as hard cover structures (elytra). L. Perm.
	Elytroneura Carpenter, 1933
	Archelytron Carpenter, 1933
	Protelytron TiIIyard, 1931 (3)
	Permelytropsis Carpenter, 1933
	Megelytron TiIIyard, 1931
	Permelytron TiIIyard, 1931
	Blattelytron TiIIyard, 1931
	Parablattelytron TiIIyard, 1931 (3) [= Acosmelytron TiIIyard, 1931]
	Protelytropsis TiIIyard, 1931
Corrodentia. Mostly diminutive short.bodied insects with large head and prominent eyes; usually winged. Perm.-Rec.
	Dichentomum TiIIyard, 1926 (2) [= Psocidium, Chaetopsocidium, Metapsocidium, Pentapsocidium, Permentomum TiIIyard, 1926]
	Progonopsocus TiIIyard, 1926 (2) [= Ancylopsocus Tillyard, 1926]
	Cyphoneura Carpenter, 1932
	Orthopsocus Carpenter, 1932
	Lithopsocidium Carpenter, 1933
	Cyphoneurodes Becker-Migdisova, 1953
Miomoptera. Small insects with similar fore and hind wings, latter lacking anal fan. Penn.-Perm.
	Delopterum Sellards, 1909 (3)
	Permembia TiIIyard, 1928
	Nugonioneura TiIIyard, 1928
Hemiptera. Diverse assemblage of mostly small insects with wings usually sloping over sides of body, mouth parts modified for piercing and sucking. Perm.-Rec.
	Archescytina TiIIyard, 1926
	Permoscytina Tillyard, 1926
	Permopsylla TiIIyard, 1926
	Paleoscytina Carpenter, 1931
	Lithoscytina Carpenter, 1933
Neuroptera. Soft. bodied insects with relatively large wings, combed antennae, and similar legs. Perm.-Rec.
	Permoraphidia TiIIyard, 1932 (2)
Glosselytrodea. Small insects with fore and hind wings almost alike, veins very straight, cross veins numerous, forming large cells, precostal area prominent, hairs on main veins. Perm.
	Permoberotha TiIIyard, 1932 [= Dictyobiella TiIIyard, 1937]
Mecoptera. Small to medium-sized slender insects, nearly all with downward prolongation of head in form of beak (scorpion flies). Perm.-Rec.
	Permopanorpa TiIIyard, 1926 (3)
	Platychorista TiIIyard, 1926 [= Protomerope TiIIyard, 1926]
	Protochorista TiIIyard, 1926
	Protopanorpa TiIIyard, 1926
	Anormochorista TiIIyard, 1926
	Lithopanorpa Carpenter, 1930
	Agetopanorpa Carpenter, 1930
	Choristosialis TiIIyard, 1932

This is a surprisingly long list. Not counting synonyms, it contains 79 genera distributed among 16 insect orders, emphasizing not only the remarkable variety of the assemblage found in early Permian deposits of a single area but also the almost incredible richness of well-preserved fossils, assiduously collected by painstaking field workers and thoroughly studied by competent specialists. Even so, knowledge surely is far from complete and further paleoecological studies are warranted. Dunbar's (1924, p. 197) paleoecological inferences are summarized in the following description.

As we have seen from a study of the lithology of the insect beds and the organic remains associated with them, the stump bed of the local section indicates here a temporary emergence when the vicinity of Insect Hill was added to the lowland bordering the Kansas sea on the northeast. The swamp conditions show that it was so low as to be poorly drained and also that the rainfall was now sufficient at least to maintain a high ground-water table in such favorable low places. The swamp, after a few hundred years, was displaced by open water, at first probably a nearly fresh lagoon but slightly connected to the nearby inland sea. Soon it became entirely a fresh-water lake or lagoon, covering the site of Insect Hill, though the abundant but fragmentary leaves of land plants give evidence that timbered lands were still adjacent. Probably the swamp had widened as the deeper portions were submerged. The bordering forests furnished a home for the prolific insect fauna, which, probably driven by occasional storms, fell into the open waters in great numbers. Since there were no fish or other animals in the lagoon to devour them, the insects floated and drifted about, sometimes settling singly, but at other times drifting together in great numbers, as flotsam is wont to do, into protected places in the lee of some obstruction to the winds. Apparently the level of the water fluctuated frequently, and thus at intervals these shallow marginal places were left dry for a short time, when the insects were stranded on the soft limy mud bottom. After a short period of drying, the insects did not float when the water returned, but stuck to the bottom where they were soon buried beneath the next film of limy deposit. The distribution of the fossil insects upon the bedding planes thus finds an easy explanation. The rich "pockets" were protected places. . . . The intimate association of broken and badly preserved fragments, along with others more sharply preserved and complete, may be attributed to the fact that the former had drifted longer and been broken and partly decayed before burial, whereas the finest specimens had fallen but a short time before burial, or possibly, in some cases had alighted or been driven directly upon the exposed mud bottom.

Although the immediate home of these insects was . . . a moist locality, nevertheless they can hardly have escaped the influence of the long-enduring dryness of the larger environment. Such delicate organisms could only be recorded in places where moisture helped to conserve them, but the insect fauna may not have been restricted in its distribution to such surroundings. Granted, however, that they inhabited only the more humid portions of the semiarid landscapes, the preceding generations . . . must have experienced, time and again, the relentless encroachment of droughts upon their shrinking retreats as the climate oscillated from less to greater aridity.

The Sellardsia assemblage of the Elmo, Kansas, area is still the most remarkable Permian ecosystem of the sort yet discovered in North America but it is likely that comparable ones lie buried in nearby or distant parts of the state and that additional ones have been destroyed by erosion. In recent years rich insect-bearing Lower Permian beds have been found in southern Kansas and northern Oklahoma (Carpenter, 1947; Tasch and Zimmerman, 1959).

Examples of Marine Assemblages

The several sorts of marine ecosystems selected for consideration out of the many, partly intergrading types observed in Kansas Pennsylvanian and Permian deposits are arranged in a sequence that corresponds approximately to the order of occurrence in the ideal cyclothem, that is, assemblages such as marked by inarticulate brachiopods (Lingula, Orbiculoidea) and little else or by associations of presumably nearest shore mollusks (mostly clams such as Myalina and pectinoid genera) either occurring alone or accompanied by low-salinity-tolerant brachiopods (especially Derbyia) and ramose bryozoans. Chonetoid brachiopods in great abundance may characterize the initial marine environment in a cyclothem. Algae of all kinds tend to be lacking in transgressive marine stages, but make appearance in company with normal marine assemblages of invertebrates in middle stages and are characteristically abundant in regressive parts of the marine cycles. Varied populations containing representatives of several phyla appear in middle deposits of cyclothems, with or without the presence of fusulinids. An abundance of fusulinids which seem to crowd out other organisms characterizes many limestones that mark culmination of sea advances. Accordingly, examples of these are taken up in a sequence that puts nearshore transgressive paleobiotopes first, then those found in middle parts of cyclothems, and finally those which typically mark regressive phases of the shallow-sea oscillations.

Some marine paleobiotopes are not classifiable according to this plan. For example, the environment (conceivably more than a single kind of environment) represented by thin but very extensive black platy shales was introduced in parts of the stratigraphic record immediately following coal-swamp conditions but elsewhere, especially in Missourian and Virgilian parts of the column, the black shale next overlies typical marine limestone containing invertebrates adapted to offshore environments. Such relations do not prove that these black shales belong to regressive stages of the cycle to which the underlying limestone belongs because the knife-sharp boundary between shale and limestone actually may represent a disconformity (paraconformity), the shale being in fact the initial deposit of a new cycle. Therefore, discussion of the black platy shale paleobiotopes is postponed to a last part of this paper.

Red Eagle-type (Orbiculoidea-Lingula) Assemblage

Sparse to common, or even locally abundant inarticulate brachiopods characterize a marine assemblage which here is called Red Eagle type because it is found to be exceptionally persistent within the Red Eagle cyclothem. Orbiculoidea and Lingula generally are present, in some places associated with many specimens of Crurithyris (Suppl. Fig. 1, 8,10,11). The assemblage chosen as type occurs in the Bennett Shale Member of the Red Eagle Limestone, which is a formation readily traced from Oklahoma to Nebraska in the lower part of the Council Grove Group (Lower Permian) and the black to very dark-gray shale containing this assemblage occurs at the very base of the member. Outcrops at the type locality of the Bennett, 0.5 mile southeast of Bennet (sic), Nebraska, are designated as containing a representative sample of this community. Other assemblages of Bennett type are well developed at many places in the Grenola Limestone of northern Kansas and southern Nebraska, in shale of the Ozawkie Limestone (Deer Creek) of central Kansas, and elsewhere. Unlike the hard platy black shales of Heebner type, the shales containing the Orbiculoidea-Lingula assemblage are soft; some appear to be rather local in occurrence, pinching out laterally, but McCrone (1963) traced the unit at the base of the Bennett nearly 300 miles and reported the presence of Orbiculoidea at virtually all observed exposures (Fig. 9). He recorded also the finding of several genera of conodonts and ostracodes and locally small teeth of fishes identified as Palaeoniscus, Idiacanthus, and Distacodus. Macerated plant debris was found to be common but spores rare. McCrone interpreted the Red Eagle-type paleobiotope as representing a poorly oxygenated shallow sea bottom which he estimated to be less than 10 feet below sea level (p. 64). He thought that waters in which the Red Eagle assemblage lived were not freely connected with the open sea (McCrone, 1963, p. 65).

Figure 9--Generalized sections of lowermost Permian deposits in four parts of Kansas region, showing stratigraphic occurrences of some ecosystems ("B," Beil-type; "RE," Red eagle-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

The environment of the Red Eagle-type Orbiculoidea-Lingula assemblage mentioned as occurring in beds classed as part of the Ozawkie Member of the Deer Creek limestone can hardly be interpreted as located in a marginal belt of a transgressing sea, for the abundant inarticulates (unassociated with other brachiopods) occur in shale next above a fusulinid-rich middle Ozawkie Limestone and below unfossiliferous earthy brown upper-most Ozawkie Limestone. These beds are excellently exposed 5 miles north of Lyndon, Osage County, Kansas (Fig. 10).

Figure 10--Correlated sections of Shawnee Group (Virgilian) units in eastern Kansas, showing stratigraphic occurrence of some specified ecosystems ("A," Avoca-type; "B," Beil-type; "DN," Doniphan-type; "H," Heebner-type; "L," Leavenworth-type; "O," Ozawkie-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Because the black Orbiculoidea-rich basal shale of the Bennett overlies the fusulinid-bearing Glenrock Limestone and is followed above by osagite of the Howe Limestone, Elias (1937a, p. 407) interpreted the Bennett as belonging to the regressive part of the Red Eagle cyclothem. Conversely, McCrone (1963, p. 50) classed the black shale as the initial deposit of a secondary transgression within the Red Eagle cycle, because the Orbiculoidea-Lingula beds lie below gray shale of the Bennett and limestone containing a varied articulate-brachiopod and bryozoan fauna, rightly interpreted (in my judgment) as representing a farther offshore, somewhat deeper water environment than that of the black shale deposition. If this is correct, the sharp boundary between the black shale and subjacent Glenrock Limestone (with its commonly abundant contained fusulinids) marks an extremely abrupt marine retreat, and missing regressive stages that should succeed the Glenrock transgressive culmination denote what amounts to a disconforrnity (paraconformity). The question of transgressive or regressive classification of the black shale is relatively unimportant as compared with determination of the nature of the paleobiotope recorded by Red Eagle-type assemblages.

Speiser-type (Derbyia) Assemblage

Shells of Derbyia (Suppl. Fig. 1, 12) in relatively large numbers and a few other euryhaline brachiopods, mingled in some deposits with similarly salinity-tolerant clams, comprise records in various Pennsylvanian and Permian cyclothems of the Kansas region of a ecosystem designated as the Speiser-type (Derbyia) assemblage. Excellent examples near the top of the Speiser Shale in the vicinity of Dexter (southeastern Cowley County) and elsewhere along outcrops of shale and shaly limestone next below the Wreford Limestone which forms a prominent escarpment across Kansas, suggest adoption of Speiser-type for a rock-unit-derived name of this distinctive assemblage. Examples invariably belong to initial marine phases of cyclothems, being found above nonmarine deposits which may contain land plants and in many places may be represented by a coal bed, and they are normally overlain by limestone bearing a variety of typical marine invertebratescorals, bryozoans, several genera of brachiopods, crinoid remains, gastropods, pelecypods, and possibly fusulinids-which are interpreted as belonging to an offshore population (Fig. 11, 12). Derbyia may be so abundant that shells are packed together almost as a coquina. Associated with it, especially in some Permian examples, are scattered individuals belonging to /uresania and Composita. Species of Myalina or Septimyalina and Aviculopecten are common constituents of the assemblage both in Pennsylvanian horizons and in the Permian. Rather unexpected constituents of some Derbyia assemblages (e. g., below the Haskell Limestone locally in Douglas County, and upper Doniphan Shale in Osage County) are well-preserved crinoid cups and common stem fragments associated with numerous ramose bryozoans.

Figure 11--Generalized sections of Lower Permian rocks extending upward from those shown in Figure 9, with examples of some ecosystems ("F," Florena-type; "S," Speiser-type; "T," Tarkio-type; "TM," Threemile-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 12--Generalized sections of Lower Permian rocks extending upward from those shown in Figure 11, with examples of some ecosystems ("T," Tarkio-type; "TM," Threemile-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

In southern Kansas especially, fossils of Derbyia assemblages in the upper Speiser Shale are silicified. In addition to fine specimens collected from weathered outcrops, numerous shells which show perfectly preserved internal features, as well as exterior surfaces, have been obtained by etching blocks of somewhat shaly rock in dilute hydrochloric acid. Hattin (1957) has described the fossil associations of this part of the Lower Permian section not only in southern Kansas but as observed at many outcrops in central and northern parts of the state. He distinguished lowermost fossiliferous beds dominated by mollusks (chiefly pectinoid pelecypods in most places, especially toward the north), and slightly higher beds dominated by Derbyia. Both groups are here included in the so-called Derbyia assemblage, which in the Speiser exposures contains the following forms (Hattin, 1957).

Organisms of the Derbyia Assemblage in the Speiser Shale just below the Wreford Limestone in Kansas (Hattin, 1957)
Algae (algal-foraminiferal intergrowths, Osagia, not common)
Invertebrates (generally well-preserved, locally abundant)
	Foraminifers: Ammodiscus, Ammovertella, Climacammina, juvenile fusulinids (uncommon), Globivalvulina, Geinitzina, Hyperammina, Tetrataxis
	Corals: Aulopora, Stereostylus
	Bryozoans: cyclostomes (encrusting), Fenestrellina, Penniretepora, Polypora, Rhabdomeson, Rhombopora, Septopora, Streblotrypa, trepostomes (encrusting), Thamniscus, ?Batostomella, ?Leioclema
	Brachiopods: Chonetes [= Neochonetes], Composita, Derbyia, Dictyoclostus [Reticulatia], Enteletes, Juresania, Orbiculoidea, Petrocrania
	Pelecypods: Allorisma, Aviculopecten, Aviculopinna, Schizodus, Septimyalina
	Gastropods: Bellerophon, Euomphalus, Euphemites, ?Cymatospira
	Arthropods: ostracodes (Amphissites, Bairdia, Bythocypris, Cavellina, Cornigella, Ellipsella, Healdia, Hollinella, Kellettina, Kirkbya, Knightina, Knoxina, Macrocypris, Monoceratina, Paraparchites, Roundyella, Silenites, ?Haworthina), trilobite, Ditomopyge
	Echinoderms: crinoids (Delocrinus, stem fragments, plates), echinoids (spines, plates), holothuroids (spicules, hooks, wheels)
	Conodonts: unidentified genera
Vertebrates (fragmentary remains of fishes, teeth, plates, bones)

Hattin (1957, p. 113) interpreted the environment of this so-called Derbyia assemblage as belonging to an offshore zone of nearly normal salinity in which not very strong turbulence resulted from wave activity. Conditions generally were favorable for many forms of life. Disseminated calcium carbonate he judged to have been derived from shell disintegration.

Doniphan-type (Rhombopora) Assemblage

In several Pennsylvanian cyclothems deposits identified as representing initial parts of marine sequences are characterized by specially abundant ramose bryozoans, generally including Rhombopora (Suppl. Fig. 1, 15) and Batostomella. This ecosystem, which rarely contains a few other invertebrates, is termed the Rhombopora assemblage (Fig. 10) and from excellent samples in the Doniphan Shale Member of the Lecompton Limestone called Doniphan type. In one exposure of this shale west of Melvern, in southern Osage County, these bryozoans weather out in such profusion that the ground is nearly concealed by a seeming cover of straw. The stems of "straw" are a trifle short (averaging about 2 inches) and many of them show bifurcation toward one end, but their diameter, straightness, and evenly cylindrical form closely approximate sections of wheat straw; moreover, all specimens at this locality have the color of wheat straw.

Snyderville-type (Neochonetes) Assemblage

The lowest marine shaly deposits of some Kansas Pennsylvanian cyclothems contain extraordinarily abundant chonetoid brachiopods which are accompanied by few other invertebrates. An assemblage of this sort is well shown in the uppermost part of the Snyderville Shale Member of the Oread Limestone as seen at many outcrops in central and northeastern Kansas and southeastern Nebraska. Nearly all of the shells belong to Neochonetes granulifer (Suppl. Fig. 2, 6) and therefore the ecosystem is named the Neochonetes assemblage of Snyderville type. Its representation in exposures at several places within a mile or two of Toronto, in southwestern Woodson County, is chosen as very typical (Fig. 13, 14). Here, as in all other localities, the lower and middle parts of the Snyderville are unfossiliferous blocky clay having physical characters of an underclay and therefore interpreted as nonmarine, but the uppermost 1 or 2 feet consist of well-laminated gray shale in which Neochonetes abounds. The shells are comparatively thin and fragile but they are well preserved, most specimens (both single valves and conjoined valves) being essentially perfect. They outnumber associated invertebrates in the ratio of approximately 5,000 to 1. Toomey (1964) observed the Snydervilletype Neochonetes assemblage in connection with detailed studies made by him on the overlying Leavenworth Limestone and has reported that northeastward from the Toronto area a very gradual increase of faunal elements other than Neochonetes can be observed, though the chonetoids remain strongly dominant. In Cass County, Nebraska, he found moderately numerous specimens of Derbyia, Crurithyris, Meekella, Juresania, Dictyoclostus [= Antiquatonia], Neospirifer, echinoid and bryozoan remains, and a pelecypod associated with abundant Neochonetes.

Figure 13--Typical section of uppermost Lawrence Shale and most of Oread Limestone near Lawrence, Kansas, showing stratigraphic occurrence of some ecosystems ("B," Beil-type; "H," Heebner-type; "K," Kereford-type; "L," Leavenworth-type; "SN," Snyderville-type; "T," Tarkio-type) (Modified from Moore and Merriam, 1959). [Included in the Acrobat PDF file of figures for this article.]

Figure 14--Typical section of uppermost Tecumseh Shale and most of Deer Creek Limestone south of Lecompton, Kansas, showing stratigraphic occurrence of some ecosystems ("B," Beil-type; "H," Heebner-type; "L," Leavenworth-type; "O," Ozawkie-type; "SN," Snyderville-type; "ST," Stranger-type) (Modified from Moore and Merriam, 1959). [Included in the Acrobat PDF file of figures for this article.]

Chonetoid assemblages which seem to correspond closely to the Neochonetes ecosystem of Snyderville type are dominated by Mesolobus and Chonetinella in various Desmoinesian cyclothems and by Chonetinella in Missourian cyclothems. Associated with these assemblages and with Neochonetes in Virgilian and Lower Permian beds at different horizons are chonetoid genera named Eolissochonetes, Lissochonetes, and Quadrochonetes; specimens of these may be common but nowhere are they found in swarms such as characterize shells of Neochonetes in the Snyderville-type assemblage.

The habitat of the chonetoid populations must have been in shallow water where a mud bottom bordered the shore, although perhaps in a belt many miles wide. Because the shale is a fine-grained deposit which is fairly well bedded and because the shells of Neochonetes are comparatively thin and fragile, disturbance of the bottom by currents and waves must have been little. Salinity may have been slightly subnormal, enough to be unfavorable for less euryhaline invertebrates, but almost surely salt content was greater than in brackish water.

Florena-type (Neochonetes-Derbyia) Assemblage

Very similar to the Snyderville-type ecosystem is the Lower Permian ecologic community of the Florena Shale Member of the Beattie Limestone as observed at most places along the outcrop. This assemblage occurs mainly in the lower few feet of the shale, next above the Cottonwood Limestone, the upper half which in northern Kansas and Nebraska is packed with slender fusulinids (chiefly Schwagerina). Therefore, the Florena assemblage, which commonly includes numerous to abundant free-weathering fusulinids in its basal few inches (and less conspicuously in higher parts of the member), is not like the Snyderville-type Neochonetes assemblage in being an initial marine community of a transgressing sea; the Florena deposits belong to the middle or regressive part of the Beattie cyclothem. At any rate, I judge it desirable to refer separately to a Florena-type Neochonetes-Derbyia assemblage (Suppl. Fig. 1, 2) and cite the very accessible and typical development of it on Kansas Highway 18 at the west edge of Manhattan as selected reference example (Fig. 15).

Figure 15--Typical section of Grenola, Eskridge, and Beattie strata just west of Manhattan, Kansas, showing stratigraphic occurrence of some ecosystems ("F," Florena-type; "M," Morrill-type; "RE," Red Eagle-type; "T," Tarkio-type; "TM," Threemile-type) (Modified from Moore and Merriam, 1959). [Included in the Acrobat PDF file of figures for this article.]

Information concerning both the FIorena fauna and varying composition of the enclosing sediment is unusually complete and detailed owing to quantitative studies by Imbrie (1955), who collected foot-by-foot samples, each weighing approximately 11 Ibs. (dry), from 24 measured sections distributed along the outcrop from Nebraska to Oklahoma. At each locality a representative collection of larger fossils was made and in the laboratory other fossils were obtained by washing and screening the samples. Also, the physical and chemical composition of each sample was determined analytically. Main results of the study have been reported and interpreted in terms of paleoecology and paleogeography (Imbrie, 1955; Imbrie, Laporte, and Merriam, 1959).

According to Imbrie, the invertebrate assemblage of the FIorena is dominated by brachiopods, among which he records Chonetes [= Neochonetes], Dictyoclostus [= Reticulatia], Juresania, Composita, Meekella, and Derbyia. My observations at many more places than reported on by Imbrie confirm this but Neochonetes is far more abundant than one may conclude from his data, partly because he measured abundance by weight in grams instead of specimen counts and partly because fossils surveyed by him were confined to those washed from his samples. Accumulations of fossils weathered from a shale ought to be representative of the fauna as a whole (unless differential transportation or solution operates to remove some kinds) but weathered-out fossils are ill-suited for bed-by-bed study of faunas. At most localities the FIorena yields a few fragments of crinoids (mostly single columnals or short stem fragments), echinoid spines and plates, parts of bryozoan zoaria (both fenestrate and ramose), and uncommonly a gastropod or two; Ditomopyge has been reported but except locally (e. g., near Grand Summit in Cowley County) trilobite remains are very rare. The Florena of southern Kansas exhibits a facies unlike that of central and northern parts of the state. This is discussed in a later part of the present paper devoted to a review of Beattie cyclothem biotopes.

Bell-type (Pulchratia) Assemblage

A marine paleobiotope which is a characteristic and prominent one in many Pennsylvanian cyclothems but not recognized in others is marked by an unusually large fauna of varied invertebrates, which here is designated as the Pulchratia assemblage (Suppl. Fig. 2, 3). Its occurrences are indicated on stratigraphic diagrams by the symbol "B," which refers to its typical representation in the Beil Limestone Member of the Lecompton Limestone near Lecompton, Kansas, especially at outcrops in the south bluffs of Kansas River at Grover Station, approximately 3 miles west of Lecompton (Perkins, Perry, and Hattin, 1962), where large collections of fossils have been made (Fig. 13, 14, 16, 17). Specimens are exceptionally well preserved, few if any forms showing abrasions such as might be caused by being moved about by currents. Fragile bryozoans and delicate small brachiopods are unbroken; fine surface ornamentation, including granules, cancellate or parallel lineation, minute spines and lamellae, generally is intact. Collections commonly contain perfect specimens best suited for museum display.

Figure 16--Typical section of uppermost Kanwaka Shale and most of Lecompton Limestone southeast of Lecompton, Kansas, showing stratigraphic occurrence of some ecosystems ("A," Avoca-type; "B," Beil-type; "H," Heebner-type; "S," Speiser-type; "ST," Stranger-type; "T," Tarkio-type) (Modified from Moore and Merriam, 1959). [Included in the Acrobat PDF file of figures for this article.]

Figure 17--Correlated sections of Shawnee Group (Virgilian) units in southeastern Kansas and northern Oklahoma, showing stratigraphic occurrence of some ecosystems ("A," Avoca-type; "B," Beil-type; "DN," Doniphan-type; "H," Heebner-type; "L," Leavenworth-type; "O," Ozawkie-type; "P," Plattsmouth-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Ecosystems of Beil type are relatively common and widely distributed in the Pennsylvanian part of the Kansas column above the Cherokee but are not well developed in most of the Permian section. They do occur, however, in the Council Grove Group (e.g., Hughes Creek-Foraker beds, Beattie Limestone of southern Kansas).

Naturally, the specific and generic composition of so-called Pulchratia assemblages differs both stratigraphically and geographcally and conditions favorable for collecting by no means are found at all outcrops of cyclothem units which are classifiable as representing this paleobiotope. Average good collections consist preponderantly of brachiopods; bryozoans, corals, and crinoid remains (cups and crowns generally rare) are commonly numerous and mollusks (small gastropods and pelecypods, chiefly) tend to be varied but not prominent; fusulinids may occur in profusion; pygidia and other remains of trilobites are almost invariably findable by searching. Most briefly described, abundance and varied composition of well-preserved invertebrates distinguish Pulchratia assemblages. Not to be overlooked is rather common occurrence of certain lamellose lettucelike types of algae.

Typical Beil-type (Pulchratia) assemblages are likely to contain a good representation of invertebrates and other organisms belonging to genera listed in the following tabulation (also partly illustrated in Suppl. Fig. 1-7).

Organisms Found Commonly to Abundantly in Beil-type (Pulchratia) Assemblages
Algae (relatively few as a rule but may include some Anchicodium or Archaeolithophyllum, incrustations of Ottonosia type, and scattered inconspicuous Osagia colonies)
Invertebrates (strongly dominant, highly varied, exceptionally well preserved)
	Foraminifers: Fusulina, Fusulinella, Triticites, Wedekindellina, Waeringella, Dunbarinella, Pseudoschwagerina
	Corals: Aulophyllum, Axophyllum, Caninia, Cladochonus, Dibunophyllum, Lophophyllidium, Michelinia, Syringopora
	Bryozoans: Batostomella, Cystodictya, Fenestrellina, Fistulipora, Goniocladia, Meekopora, Meekoporella, Penniretepora, Polypora, Rhabdomeson, Rhombopora, Septopora, Streblotrypa, Tabulipora, Thamniscus
	Brachiopods: (Orthidina) Enteletes, Rhipidomella, Schizophoria, (Strophomenidina) Derbyia, Derbyoides, Meekella, Orthotetina, (Chonetidina) Chonetinella, Eolissochonetes, Lissochonetes, Mesolobus, Neochonetes, Quadrochonetes, (Productidina) Antiquatonia, Cancrinella, Desmoinesia, Echinaria, Hystriculina, Juresania, Kozlowskia, Linoproductus, Pulchratia, Retaria, Reticulatia (Suppl. Figs. 2, 3, 5), (Oldhaminidina) Poikilosakos, (Rhynchonellidina) Wellerella, (Retziidina) Hustedia, (Athyrididina) Cleiothyridina, Composita, (Spiriferidina) Crurithyris, Neospirifer, Phricodothyris, Punctospirifer, (Terebratulidina) Cryptacanthia, Dielasma
	Mollusks: (Gastropods) Bellerophon, Euphemites, Glabrocingulum, Ianthinopsis, Meekospira, Naticopsis, Phymatopleura, Soleniscus, Straparolus, Trachydomia, Trepospira, Worthenia (Suppl. Fig. 6, 7), (Bivalves) Acanthopecten, Allorisma, Aviculopecten, Edmondia, Leda, Myalina, Nucula, Nuculopsis, Parallelodon, Pinna, Pleurophorus, Pseudomonotis, Schizodus, Yoldia (Suppl. Fig. 4), (Cephalopods) Metacoceras, Pseudorthoceras
	Arthropods: (Trilobites) Ameura, Ditomopyge, Paladin (Suppl. Fig. 2), (Ostracodes) inconspicuous but common
	Echinoderms: (Crinoids) locally numerous dorsal cups, rare crowns, abundant fragmental remains, mostly columnals blit some plates, (Echinoids) Archaeocidaris spines and plates
Vertebrates (generally rare fish teeth)

Brachiopods named in the foregoing list are grouped in suborders which are recognized in the Treatise on Invertebrate Paleontology; all have terminations in -idina. Paleontologists generally familiar with Pennsylvanian and Permian invertebrates of the Midcontinent region are likely to miss familiar generic names (e.g., Ambocoelia, Chonetes, Chonetina, Dictyoclostus, Echinoconchus, Marginifera, Productus, Pustula, Spiriferina, Squamularia--all now recognized as restricted to older rocks or to Permian outside of North America or replaced by senior synonyms) and they are called on to learn that many well-known species presently masquerade in new binominal combinations. This is illustrated by names of brachiopods selected from Condra and Dunbar (1932) accompanied by their modified equivalents as given by Muir-Wood and Cooper (1960), Muir-Wood (1962) and Treatise authors (Brachiopoda, Part H, 1964).

The paleobiotope represented by the Beil-type (Pulchratia) assemblage is thought to be one that existed in clear sunlit shallow waters (estimated less than 20 m. on the average) far from nearest shores (probably 50 to 100 miles distant). The environment is interpreted to belong in the culminating marine part of the cyclothem in which it is recorded by presence of the assemblage and the nature of the sediments (generally thin-bedded carbonate mud, now limestone) surrounding the fossils. I can suggest no diagnostic characters as basis for distinguishing Beil-type paleobiotopes from such others as are called Tarkio type (with Triticites assemblage), Wakarusa type (with Ottonosia-Reticulatia assemblage), and Avoca type (with Amblysiphonella assemblage) , even though each seems to possess persistent features of its own. At the present stage of paleoecological inquiry, it is judged desirable to treat the various types separately, rather than to lump them on the ground that all of those mentioned are characterized by common occurrence of fusulinids in the organic com. munity. Why the Beil-type ecosystems are marked by special abundance and variety of invertebrates in contrast with random distribution of a much smaller number and taxonomically restricted sea-bottom population of invertebrates is a problem for study, first by comparing as analytically as possible all recognized Beil-type assemblages among themselves. The same sort of comparisons of somewhat similar types with one another may ultimately lead to discrimination of sought-for paleoecological criteria.

Plattsmouth-type (Caninia) Assemblage

An ecologic community which may be construed as merely a variant of the Beil-type (Pulchratia) assemblage is observed at several places in Kansas and Nebraska in such rock units as the Beil and Plattsmouth Limestones (Fig. 17, 18). It is characterized by abundance of corals, especially Caninia (Suppl. Fig. 4, 24) and Syringopora, and by a less varied fauna of brachiopods, bryozoans, and mollusks, all represented by fewer individuals than in the typical Pulchratia assemblage. Fusulinids generally are common, however. The coral-dominated ecosystem is named the Plattsmouth-type (Caninia) assemblage, mainly in order to avoid duplication of Beil-type as applied to both the coral-rich and Pulchratia assemblages. Species belonging to the mentioned coral genera are minor elements of most Pulchratia assemblages.

Tarkio-type (Triticites) Assemblage

The most common marine ecologic assemblage of organisms found in Pennsylvanian and Permian cyclothems of Kansas consists predominantly, in many places almost exclusively, of fusulinid foraminifers. Genera represented, differing according to stratigraphic horizon, include Triticites (Suppl. Fig. 5, 7) most commonly and therefore the assemblage associated with this paleobiotope is named the Tarkio-type (Triticites) assemblage and the excellent sample of it seen in exposures of the Tarkio Limestone on US Highway 40 near the Shawnee-Wabaunsee county line is indicated as typical. Genera in other so-called Triticites assemblages include Kansanella, Fusulina, Fusulinella, Dunbarinella, Waeringella, Wedekindellina, Schwagerina, Paraschwagerina, and Pseudoschwagerina, as well as inconspicuous Schubertella, Millerella, Staffella, and Oketaella (Fig. 9-11, 13, 15-20).

Figure 18--Correlated sections of lower Shawnee (Virgilian) units in eastern Kansas, showing stratigraphic occurrences of some ecosystems ("H," Heebner-type; "L," Leavenworth-type; "P," Plattsmouth-type; "SN," Snyderville-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 19--Correlated sections of lower Shawnee (Virgilian) units in northeastern Kansas and adjacent parts of Missouri and Nebraska, showing stratigraphic occurrences of some specified ecosystems ("A," Avoca-type; "B," Beil-type; "H," Heebner-type; "K," Kereford-type; "L," Leavenworth-type; "SN," Snyderville-type; "ST," Stranger-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 20--Correlated sections of Shawnee (Virgilian) units in northeastern Kansas and adjacent parts of Missouri, Iowa, and Nebraska, showing stratigraphic occurrences of some specified ecosystems ("A," Avoca-type; "B," Beil-type; "H," Heebner-type; "L," Leavenworth-type; "O," Ozawkie-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Some beds are mostly composed of fusulinids and in these the shells may be crowded so closely together that not only is room lacking for other invertebrates but not much space is occupied by rock matrix. Soft or shaly limestones of this type weather readily in manner that yields literally bushels of free specimens (e.g., Triticites ventricosus, Dunbarinella hughesensis) at some Hughes Creek Shale outcrops in central and southern Kansas; Dunbarinella glenensis at some Glenrock Limestone exposures in the same region (Fig. 9). The upper part of the Spring Branch Limestone and entire thickness of the Big Spring Limestone (both Lecompton) at many localities are largely formed by the shells of Triticites cullomensis (Fig. 10, 16-23). Large white specimens of T. ventricosus spread throughout massive brown Tarkio Limestone several feet thick give a porphyrylike appearance of groundmass and phenocrysts to the rock which is very striking, and virtually no other fossils are seen. Across nearly all of Kansas the upper half of the Cottonwood Limestone is a uniform massive layer of even-textured rock in which almost the only fossils are extremely abundant specimens of elongate, slender fusulinids (Schwagerina emaciata, S. jewetti). These are examples of Triticites assemblages and it is obvious that they must represent a distinctive sort of paleobiotope which recurred many times and generally was extremely uniform and widespread.

Figure 21--Correlated sections of upper Wabaunsee (Virgilian) units in eastern Kansas, showing stratigraphic occurrences of some specified ecosystems (location in Greenwood and Lyon Counties shown on index map, Figure 22) ("M," Morrill-type; "ST," Stranger-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 22--Correlated sections of upper Wabaunsee (Virgilian) units in eastern Kansas, showing stratigraphic occurrences of some specified ecosystems ("ST," Stranger-type; "T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 23--Correlated sections of upper Wabaunsee (Virgilian) units in northeastern Kansas and southeastern Nebraska, showing stratigraphic occurrences of some specified ecosystems (location shown on index map, Figure 22) ("T," Tarkio-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

The fact that Triticites and other fusulinids are by no means restricted to so-called Triticites assemblages certainly indicates that paleobiotopes characterized by profuse occurrence of these foraminifers, so great in number that they seem to crowd out other invertebrates, probably were not radically different from shallow-sea environments in which the fusulinids were proportionally and actually much fewer. Because fusulinid-bearing beds almost invariably overlie and underlie marine deposits which lack them, these latter being discriminated on the basis of their cyclic relationships as belonging to initial or intermediate transgressive phases of inundation by sea waters on one hand or to retreatal phases on the other; the strata containing fusulinids are in the middle of the marine parts of cyclothems. At least this is true ideally. Triticites is not a marker of deepest parts of invading Pennsylvanian and Permian seas but presumably of intermediate to greatest distances from sea margins.

Both in Pennsylvanian and Permian parts of the Kansas column one may observe stratigraphically adjacent but obviously dissimilar ecosystems classifiable as Triticites assemblages (e.g., abundant T. ventricosus, a very robust form, as almost exclusive constituent of the Tarkio Limestone assemblage, followed a few feet higher by the Maple Hill Limestone assemblage containing exclusively small and slender Triticites). Clearly, the Maple Hill fusulinid population is not composed of lineal descendants of Tarkio stocks (which presumably do appear in T. ventricosus of the Hughes Creek, Grenola, and some other Lower Permian units). Question arises whether Maple Hill paleoecology was different enough from that of the Tarkio sea to explain the faunal dissimilarity and one may ask where the post-Tarkio populations of T. ventricosus came from, since this species was not a continuous inhabitant of the Kansas region in late Pennsylvanian and early Permian time. Such problems have been considered previously by me, arriving at the conclusion that fusulinids of successive cyclothems mostly do not show stages in the evolution of identifiable lineages which contributed to the paleontological record in Kansas by their presence in repeated marine invasions (Moore, 1954).

It is also noteworthy that in some cyclothems (e.g., Foraker, Beattie, discussed by Elias, 1962, p. 108-110; Red Eagle, reported by McCrone, 1963, p. 64, 96-105) fusulinid-rich beds alternate with layers containing more or less abundant fossils of other sorts, mainly brachiopods, but lacking fusulinids. Oscillatory changes in local sea-bottom environments should not be considered exceptional and surely they do not demand explanation in terms of significant movements of nearest strand lines or of appreciable changes in water depths. The successive fusulinid populations in examples of this sort generally are similar in generic and specific composition.

The Cottonwood Limestone was cited in the first part of the discussion of Triticites assemblages as an excellent example, although fusulinids other than Triticites make up the Cottonwood community. This is given attention in a later part of the present paper in a section devoted to review of biotopes of the Beattie cyclothem.

Wakarusa-type (Ottonosia-Reticulatia) Assemblage

An ecologic community of organisms which seems clearly to differ from those here designated as Beil-type (Pulchratia) assemblage and Tarkio-type (Triticites) assemblage but nevertheless corresponding to them as regards position in the marine part of cyclothems is considered next. It is named the Wakarusa-type (Ottonosia-Reticulatia) assemblage and among several examples of it which might be chosen, its occurrence as seen in outcrops of the Wakarusa Limestone on US Highway 54 approximately 3 miles west of Eureka, in Greenwood County, is cited for reference (Fig. 24, 25). Main observed features are moderately large specimens of the productidine genus Reticulatia (Suppl. Fig. 5, 10), partly to almost entirely incrusted by laminated algal-foraminiferal colonies typically representative of Ottonosia. Such specimens are well scattered at random in the fine granular matrix of the rock and they seem to display no consistent orientation. They are not crowded together in any way. The growths of Ottonosia are quite variable in thickness, in different colonies or parts of the same colony, ranging from approximately 2 to 30 mm. A tendency toward maximum coverage and thickness of the colonies on upper surfaces of their support indicates growth on shells fairly well stabilized in position on the sea floor and consequently an absence of strong currents or wave-induced turbulence. Associated fossils include several other genera of brachiopods, a few mollusks (both snails and bivalves), some bryozoans and rare corals, and sparse to common fusulinids and crinoid remains (chiefly stem fragments). Ottonosia may be found on various shells and incrusting the crinoid stems on all sides, covering even the articular surface at one or both ends. Of course, this proves that such stems were disarticulated when the Ottonosia colonies were developing around them, as they might on occasionally rolled loose pebbles. Specimens of Osagia have been observed but are not common constituents of the Wakarusa-type assemblage.

Figure 24--Correlated sections of Wabaunsee (Virgilian) units in northeastern Kansas, showing stratigraphic occurrences of some specified ecosystems (location indicated on inset map, Figure 25) ("T," Tarkio-type; "W," Wakarusa-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Figure 25--Correlated sections of Wabaunsee (Virgilian) units in northeastern Kansas, showing stratigraphic occurrences of some specified ecosystems ("T," Tarkio-type; "W," Wakarusa-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

Assemblages which closely resemble that widely distributed in the Wakarusa cyclothem, duplicating it in fact, are found in the Church cyclothem of the Howard Limestone and the Avoca cyclothem of the Lecompton Limestone, to mention only two examples. Paleoecological research obviously calls for detailed comparisons of these stratigraphically well-separated occurrences, and it needs also to explore resemblances and differences to be found in comparing Wakarusa-type assemblages with such Ottonosia- and Reticulatia- or Antiguatonia-containing communities as Beil- and Plattsmouth-type assemblages and others. Large algal "biscuits" of Ottonosia or Somphospongia with initial growths on very inconspicuous supports are seen, for example, on the upper surface of the Burlingame Limestone, Howe Limestone, etc., at least locally associated with abundant Osagia (McCrone, 1963, p. 30). What environmental conditions do these signify? Johnson (1946, 1963) has described and illustrated Pennsylvanian and Permian algae extensively, including numerous forms from Kansas, but unhappily has written virtually nothing (less than 6 lines) on paleoecological interpretation of them.

Observations on geographic variations in composition of the Wakarusa Limestone assemblage previously have been noted' by Moore (1949, p. 10). In northern Kansas this organic group is dominated by robust fusulinids in association with common large productidine brachiopods (Reticulatia), fistuliporoid and other bryozoan colonies, crinoid remains, and the like, Ottonosia being present but not very common. In central Kansas fusulinids are less numerous and other elements of the assemblage, including Ottonosia, are more prominent. In southern Kansas, the Wakarusa, readily and almost continuously traceable along the outcrop, is found to have still fewer fusulinids, but more numerous colonies of Ottonosia. This trend continues into Oklahoma where fusulinids and most other invertebrates vanish from the Wakarusa, whereas Ottonosia is the most conspicuous fossil, so much so that this rock unit came to be known in early stratigraphic classification of northern Oklahoma Pennsylvanian formations as the Cryptozoon.bearing Limestone, a member of the so-called Buck Creek Formation (Beckwith, 1928, p. 12). The Cryptozoon referred to is the same as Ottonosia. Its prominence and usefulness as a horizon-marker were first reported by Heald (1919, p. 215) . The geographic variations reported must have paleoecological significance, in my opinion indicating that the Wakarusa-type assemblage of northern Kansas, with abundant Triticites and relatively few Ottonosia, represents a paleobiotope in a far offshore locacation, whereas the presumably contemporaneous Ottonosia-dominated, fusulinid-Iacking assemblage in the Wakarusa Limestone of Osage County, Oklahoma, denotes a paleobiotope located comparatively nearshore, possibly less than 30 miles or so from a strand line to the south.

Avoca-type (Amblysiphonella) Assemblage

The sponge named Amblysiphonella (Suppl. Fig. 1, 21) is a marker of marine units in some Kansas Pennsylvanian cyclothems, occurring within or rather commonly on the underside of limestone beds (e. g., Avoca Limestone, Fig. 10, 16-20; lowermost part of Topeka Limestone, Fig. 20). A so-called Avoca-type (Amblysiphonella) assemblage is distinguished by the presence of this genus and a reference example of it is cited from good exposures of the Avoca Limestone in a small east-flowing creek bed and banks 2 miles north of Big Springs. The containing rock is almost invariably a massive limestone ranging in thickness from 1 to 5 or 6 feet. The fact that moderately large fusulinids, robust Antiquatonia, crinoid columnals, and prominent algal-foraminiferal colonies of Ottonosia are characteristically associated with the occurrence of Amblysiphonella indicates that the paleobiotope represented by the assemblage is closely comparable to some others which here have been classed as marked by the Wakarusa-type (Ottonosia-Reticulatia) assemblage (e.g., Church Limestone Member of the Howard Limestone and Wakarusa Limestone (Fig. 21, 22). Possibly no significant paleoecological distinctions in the examples cited warrant separation of one from another. At any rate, the Avoca-type assemblage is very typically developed in central and southern Kansas, as well as in northern Kansas and Nebraska.

Threemile (Fenestrellina-Composita) Assemblage

Cherty and chalky limestone units which are very persistent characterize the Chase Group of the Kansas Lower Permian (e.g., Wreford, Barneston, Winfield Limestones). They are mainly composed of comminuted invertebrate remains and because of their very low content of clastic sediment are judged to represent culminating marine phases of cyclothems. In this respect they are interpreted as homologous with Pennsylvanian deposits such as the Plattsmouth Limestone (also commonly chert-bearing) characterized by its content of the Pulchratia assemblage. The Permian limestones referred to are only sparsely fossiliferous at most outcrops, however, and the fauna found in them is neither varied nor even locally marked by abundance of individuals, though fragmentary remains of benthonic organisms may be extremely common. The brachiopod Composita (Suppl. Fig. 5, 1) can be seen at virtually every exposure and fenestrate bryozoans are ubiquitous. The Threemile Limestone Member of the Wreford Limestone is selected for reference and the name Threemile-type (Composita-Fenestrellina) assemblage is applied to the whole community of organisms, including both relatively complete and very fragmentary remains (Fig. 26). Fusulinids (chiefly Triticites and Dunbarinella) are abundant in parts of the Florence Limestone (lower Barneston) but generally this group of fossils is absent. Scattered spines and plates of echinoids are characteristic.

Figure 26--Generalized sections of Lower Permian rocks extending upward from those given in Figure 11, showing stratigraphic occurrence of some ecosystems ("S," Speiser-type; "TM," Threemile-type) (Moore). [Included in the Acrobat PDF file of figures for this article.]

The most comprehensively studied Composita-Fenestrellina assemblages are those of the Wreford Limestone (Hattin, 1957) and these are reported to contain the following organisms.

Composition of Threemile (Composita-Fenestrellina) Assemblages (Hattin, 1957)
Algae (Girvanella, sparse algal-foraminiferal Osagia)
Invertebrates (generally sparse, locally common, many fragmentary)
	Foraminifers: Ammodiscus, Ammovertella, Globivalvulina, Tetrataxis, Schwagerina (single small area in central Chase County)
	Sponges: siliceous spicules
	Corals: Aulopora, Dibunophyllum, Stereostylus (very locally in reef-like masses)
	Bryozoans: Fenestrellina, Penniretepora, Polypora, Rhombopora, Septopora, Streblotrypa, Tabulipora, Thamniscus, encrusting cyclostomes
	Brachiopods: Chonetes [= Neochonetes], Composita, Derbyia, Dictyoclostus [= Reticulatia], Enteletes, Orbiculoidea, Wellerella
	Mollusks: Aviculopecten, Aviculopinna, Septimyalina, small gastropods (unidentified)
	Arthropods: Bairdia, other unidentified ostracodes, trilobite (Ditomopyge)
	Echinoderms: Delocrinus, crinoid stem fragments, echinoid spines and plates
Vertebrates (fragmentary remains, ?fish teeth)

According to Hattin (1957, p. 69, 92) the coral component of the Threemile assemblage deserves emphasis because at least a few specimens can be found at almost every exposure of the Wreford Limestone and they are abundant in the uppermost 12 inches or so of the Threemile Member at a few places. The prevailingly fine granular texture of the limestone indicates a high degree of disintegration of sea-bottom organisms, yet a considerable part of the material is identifiable to the extent of recognizing derivation from bryozoans such as Fenestrellina, echinoderms (both crinoids and echinoids), brachiopods, and mollusks. The sediment closely corresponds to the lower part of the Cottonwood Limestone called bioclastic by Laporte (1962), for example, which also is thought to represent an accumulation of organic remains far from shore. The agency or agencies of fragmentation are undetermined.

Leavenworth-type (Isogramma) Assemblage

Isogramma (Suppl. Fig. 5, 4) is a distinctive but rare brachiopod and therefore its use for designating numerous puzzling organic assemblages and their paleobiotopes in the Pennsylvanian part of the Kansas rock column is decidely inappropriate if widespread occurrence and even local abundance are considered to be criteria for choosing a name. Actually, the only known specimens of Isogramma from Kansas come from the basal part of the Rock Bluff Limestone Member of the Deer Creek Limestone at localities in Osage County south of Topeka. It is the assemblage and biotope represented by the limestone containing this fossil that I wish to discriminate and it happens that generic names applied to other organisms in the Rock Bluff, Leavenworth, and homologous units are too general in occurrence elsewhere and too nondiagnostic of these assemblages to offer a good alternative name. Isogramma is adopted because it is unique and because it calls attention to neglect in paleontological study of this and closely similar stratigraphic units (e.g., Middle Creek. DuBois, etc., see, Fig. 10, 13, 14, 17-20). The Rock Bluff Limestone is an excellent example of deposits containing this assemblage for which reference exposures on US Highway 75 just north and south of Dragoon Creek, 5 miles north of Lyndon, in Osage County, are cited. There Isogramma has been collected. The excellent exposures of the Leavenworth Limestone on the Kansas Turnpike northwest of Lawrence are indicated as typical of this unit.

Physical characters of rock units classed as representing the biotope of the Isogramma assemblage are specially important, seemingly more so than the nature of organic remains contained in them, as evidence of the environmental conditions which need to be understood. All examples of these units are dense, brittle, rather dark bluish, only slightly ferruginous limestones which lack pe