THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS

November 30, 1967 Paper 24

REVISION OF SUBORDER CYATHOCRININA (CLASS CRINOIDEA) N. GARY LANE Department of Geology, University of California, Los Angeles

ABSTRACT

The suborder Cyathocrinina is divided into three superfamilies named Palaeocrinacea, Cyathocrinitacea and C,odiacrinacea. Each of the first two includes families judged by MOORE & LAUDON (1943) to be closely related, one superfamily differing from the other in the presence or absence of an anal sac. The Codiacrinacea is a new superfamily containing which earlier were grouped in the family Codiacrinidae, but now are thought to represent three separate lineages that merit separation at the family level. The Codiacrini- dae, as restricted, includes Codiacrinacea with five arm-bearing radials, and such crinoids range from the into the . The new family Sycocrinitidae includes Lower to Permian genera that have only the D radial bearing an arm, the other radials being either present or absent. The new family Streblocrinidae consists of abrachiate (armless) crinoids in which the radials atrophied and disappeared during the Devonian, and pseudomonocyclic genera without radials which continue into the Permian.

INTRODUCTION During preparation of materials on the sub- of grouping these three families into a separate order Cyathocrinina for Part T (Class Crinoidea) superfamily became evident. many years superfamilies were not used in for the Treatise on Invertebrate Paleontology, it For fossil crinoids, which were became evident that revision of the family Codia- the classification of ranked into subclasses and orders with their con- crinidae BATHER, 1899, was called for before that tained families. Relatively few suborders were group of crinoids would be in a taxonomic frame- recognized by BATHER (1899) and by MOORE & work suitable for inclusion in the Treatise. The LAUDON (1943), but the classification was thor- family included three phyletically distinct assem- oughly revised in 1953 by UBAGHS who established that were thought to warrant blages of crinoids several new suborders and superfamilies, especially of the three separation at the family level, two among the camerate and inadunate crinoids. Con- groups having separate evolutionary history from sequently, ample precedent exists for division of the Devonian through the Permian. Nevertheless, the Cyathocrinina at the superfamily level. these three lineages are thought to have had a MOORE & LAUDON (1943, p. 37) suggested that common, pre-Middle Devonian ancestry and to families which they classed in the Cyathocrinina stand closer to each other than to other families of fell into two relatively distinct groups, one consist- the Cyathocrinina. Consequently, the desirability ing of earliest known cyathocrinoids as well as 2 The University of Kansas Paleontological Contributions—Paper 24 specialized and Devonian families, all of the suborder, exclusive of the codiacrinids, share which have a low tegmen and an anal opening several common features, the most important of directly through the tegmen or the side of the cup. which is that all have an elongate anal sac. These These families are grouped here into the super- families are assembled as the superfamily Cyatho- family Palaeocrinacea. The remaining families in crinitacea (Fig. 1).

SUPERFAMILY CODIACRINACEA The crinoids that have been grouped, until almost exclusively of small crinoids known from now, in the family Codiacrinidae are a diverse thecae with arms and columns rarely preserved. assemblage that includes 31 nominal genera. Pale- Some individuals are small, only 1 or 2 mm. in ontologists have disagreed concerning evolutionary maximum dimension, and can be classed as micro- trends within this group and their differing opin- crinoids, whereas others are several times larger, ions about the phylogeny of its components never but rarely more than 1 cm. in height. The dorsal have been resolved satisfactorily, mainly because cup typically is higher than wide, with all plates there has been no comprehensive review of all visible in side view, and consists of either two or genera that attempts to fit them into a coherent three circlets of plates. Infrabasals may number evolutionary pattern. In recent years important five, three, or be fused into a single plate; basais new studies on oldest known codiacrinaceans from are the five largest plates in the cup, although ex- Devonian and Mississippian rocks have shed light ceptionally only three basais may be present. The on the evolutionary history of these crinoids. These radials are usually small, may or may not have factors need to be taken into account in a revision arm-bearing articular facets developed on their such as this, and necessitate discussion too lengthy distal edges, and may number five, three, or be for appropriate inclusion in the Treatise. absent. Those genera characterized by absence of The superfamily Codiacrinacea is composed radials have a two-circlet pseudomonocyclic cup, the remaining circlets being the infrabasals and basais, rather than the basais and radials, as in the true monocyclic condition. One important aspect of study o of codiacrinaceans is the necessity for dif- -o ferentiating diminutive pseudomonocyclic mem- bers included o in the superfamily from small, 0 o o truly monocyclic crinoids 0 -o of the disparid family Q) Allagecrinidae. (.) o (.5 o 0 CRITERIA FOR DISTINGUISHING DIMINUTIVE CODIACRINACEANS AND ALLAGECRINIDS

.cEn Small monocyclic allagecrinids, like Kallimor- Q) phocrinus and Hybochilocrinus, bear close resem- o blance to microscopic codiacrinaceans such as Coenocystis or Hemistreptacron. In these two unrelated groups the dorsal cup has only two cir- (./5 clets of plates, basais and radials in the allagecri- nids and infrabasals and basais in the codiacrina- ceans. In the latter assemblage the radials are postulated to have atrophied and disappeared, re- o sulting in a pseudomonocyclic condition. The fol- 6_ lowing morphologic criteria are available for dis- tinguishing these two groups of microcrinoids. 1) Allagecrinids, even small specimens less Flo. 1. Evolution of suborder Cyathocrinina. than 1 mm. in maximum dimension, have arm- Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 3

0 0 Pennsylvanian 0000 0 C7 O Clistocrinus

innnan 6 0 6.00 uuuuu 9 ç_i ODU Lageniocrinus Dichostreblocrinus

Mississippian

of10,,oronon OVoroV&9 L ampadosocrinus

AAA() 0 0 0 0U 0U Pentececrinus Ann,nn Devonian oanon 0 0\1 0 Q Streblocrinus Ç17. ‹R z Tytthocrmus

Silurian Thalamocrinus

FIG. 2. Devonian-through-Pennsylvanian genera of Streblocriniciae, n.fam. [The A ray and AE interray are the farthest right plates in each diagram. Radials are black and anal plates have vertical ruling.]

4 The University of Kansas Paleontological Contributions—Paper 24 bearing articular facets on the upper edges of one NIEWOEHNER, from Devonian-Mississippian transi- or more of the second circlet of cup plates. These tion beds, which is the oldest known abrachiate plates are correctly designated as radials and the (armless) codiacrinacean, it seems clear that two proximal circlet as basais. Codiacrinaceans with morphologically dissimilar groups of these crinoids only two circlets of plates in the cup do not display persisted from Devonian through Permian time. articular facets on plates of the second circlet. One of the groups lacked radial plates from the These plates are judged to be basais and the prox- beginning, so were pseudomonocyclic (Fig. 2, 3). imal circlet infrabasals, the radials having atro- The tendency for radials to atrophy and disappear phied and disappeared. The difference cannot be is foreshadowed by the Middle Devonian genus ascribed to ontogenetic change—that two-circlet Streblocrinus KoENIG & MEYER (1965), which has cups without facets are immature monocyclic only three small radial plates. Codiacrinaceans forms that have not yet developed facets on the with five arm-bearing radials begin with Codia- second (radial) circlet—because many specimens crinus in the Devonian and continue through to of two-circlet codiacrinaceans are several times the Permian (Fig. 4, 5). A third group, typified larger than much smaller arm-bearing allagecri- by Sycocrinites, has five radials, only one of which nids, yet do not display facets. Conclusive evidence is arm-bearing, the others being reduced in size for this argument is found in codiacrinaceans and lacking radial facets (Fig. 6). This group is with three-circlet cups like that of Embryocrinus first found in Lower Carboniferous rocks, and (Perm.) or Streblocrinus (Dey.), in which the continues into the Permian. radials are much reduced in size, lack facets, and At least two possible phyletic schemes may are at the point of disappearing. account for the temporal distribution of genera in 2) Many allagecrinids have radial plates un- the three morphologic groups distinguished on equally developed in size, and some have differ- the basis of number of arm-bearing radials. ences in the number of arms borne by radials Informally we may designate the three groups within the same cup. These allagrecrinids consis- as abrachiate, monobrachiate, and pentabrachiate tently display a bilateral symmetry plane in an codiacrinaceans. E-BC direction. No reported codiacrinacean has Each of these three groups could represent a this symmetry direction, even though asymmetric separate phyletic lineage. The abrachiate genera radials are known in several genera. developed in the Devonian from an ancestor like not 3) Microscopic allagecrinids typically do Streblocrinus with complete atrophy of the radials have an anal opening in the side of the cup below by Late Devonian or Early Mississippian time circlet. Presumably the anal the top of the radial (Pentececrinus). The pentabrachiate forms began opening of these crinoids was situated internal to with Codiacrinus in the Devonian and continued the oral plates, which probably were movable. All through to the Permian. The monobrachiate gen- but a few codiacrinacean genera have an anus era, which first appear in the Lower Carbonifer- opening to the exterior through the theca, and all ous, would have been derived initially from a but two of the pseudomonocyclic cod iacrinaceans pentabrachiate genus by loss of arms on all but one have such an opening. of the radial plates, and then continued on as a Utilization of these morphologic criteria should separate lineage into the Permian. make the distinction clear between the two major Alternatively, the abrachiate genera could rep- groups of Paleozoic two-circlet microcrinoids. resent a series of unrelated but homeomorphic genera that repeatedly evolved from pentabrachi- EVOLUTION OF CODIACRINACEANS ate forms by loss of radials. This pattern of evolu- Continuing disagreement among paleontolo- tionary reiteration would be similar to that of Mes- gists on the phylogeny of codiacrinaceans (YAKOV- ozoic ammonoids. If this were the case, then one LEV, 1928; WANNER, 1929; WELLER, 1930; PECK, might postulate that the rnonobrachiate genera 1936; KIRK, 1940; KoExic & NIEWOEHNER, 1959) represent transitional stages in the evolutionary will not be reviewed here in detail because this lines leading to abrachiate types. controversy has been adequately summarized in Various workers (KIRK, 1940; PECK, 1936) the readily available latest two cited papers. With have suggested that the Permian Embryocrinus, the recent description of Pentececrinus KOENIG & which has five small abrachiate radials, may have

Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 5

00A0o 0000o

Coenocystis

A7\nn CTL7 =E7 Hemistreptacron 60,(\60 ODPV0 Dichostreblocrinus

Fin. 3. Permian representatives of the Streblocrinidae. [Explanation of orientation and symbols as for Fig. 21 evolved from a pseudomonocyclic form like La- are a conservative, more slowly evolving group geniocrinus de Koninck, of the Lower Carbonifer- than the abrachiate types. ous, by a secondary reappearance of radial plates If one differentiates three groups of codiacrina- late in the evolutionary history of the group. It ceans on the basis of the number of arm-bearing seems more reasonable, however, to regard Em- radial plates, as was done above, several other mor- bryocrinus as a descendant of pentabrachiate codia- phologic features serve to establish the morpho- crinaceans, which only began to effect reduction logic distinctiveness of the groups and buttress the in radial plates in the Permian, a process that the argument that each is a separate phylogenetic en- abrachiate group began in the Devonian. In this tity, at least from the Early Carboniferous through view the dicyclic forms with radials still present the Permian.

6 The University of Kansas Paleontological Contributions—Paper 24

• iiit 41 46 O n.Q7•0•9•0n ( .Ç2.00 0 •o Hypocrinus (Perm.) Embryocrinus (Perm.)

Amphipsalidocrinus

Pennsylvanian

C) 00. 0 00 L Lc Iiikn4&cand • 111,•• 0 0 00000 Edapocr inus Ç7. A bra chi ocrinus

Mississippian 4* **# 00000 Q Q 0 Cydonocrinus t

Devon ia n Û 0 00 00 0? Codiacrinus

Silurian Thalami ocrinus

Fm. 4. Evolution of Devonian-through-Pennsylvanian genera of Codiacrinidae. [Explanation of orientation and symbols as for Fig 2, except for stippled madreporitic posterior oral.] Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 7 Vviovki0 r-P4) °no A sy mmet rocrinus

ovoivovovov 9 Tenagocrinus

00000613C 000013 GP 41 0 0 0 0 0 <;) 9 Prochoidiocrinus Nereocrinus annLn ()vvonovirk,v Cron oc rinus

069 ;969040° / 4kirv 9 Q .Ç7 o!o Bolbocrinus Thetidicrinus Aa,A,,n • la 09Ci. CD C •O

Embryocrinus Hypocrinus

FIG. 5. Evolution of Permian codiacrinaceans. [Explanation of orientation and symbols as for Fig. 2.]

The Devonian and some Lower Carboniferous ture. On the other hand, the oldest pentabrachiate abrachiate genera have five unfused infrabasal genus (Codiacrinus), and only known Devonian plates, which surely is a generalized condition de- of this type, has only three infrabasals, four noting little evolutionary advancement of this fea- of the original five being fused into two larger 8 The University of Kansas Paleontological Contributions—Paper 24

4A p

0 0 00 ° ç:77 Monobrachiocrinus

• q1111 Oil 00 r-- 7 Ç7 Parasycocrinus

• IV•4 n 40••• n0000 nO11 Permian Ç:7 Q <;7 K? <;) Metasycocrinus Allosycocrinus

Pennsylvanian

iplit 4.. Mississippian 00902 v o Sycocrinites FIG. 6. Evolution of Sycocrinitidae, n.fam. [Explanation of orientation and symbols as for Fig. 21

plates. Consequently, the oldest known abrachiate forms the anal opening typically is directly above forms could not have evolved from the oldest the posterior basal, either between basals and ra- pentabrachiate type, which is evolutionarily more dials, between radials, or between radials and advanced in structure of the infrabasal circlet. The orals. In abrachiate genera, however, the anal condition of the infrabasals then suggests either a opening is above and to the right of the posterior separate origin for the two groups or a common basal from Devonian to Permian time, when a but as yet unknown pre-Middle Devonian ancestor. trend begins for leftward shift of the anal opening Another morphologic feature that seems to until it is directly above the posterior basal (Fig. indicate a long separate phyletic history for the 7). pentabrachiate and abrachiate groups is relative A third feature that can be cited is that all pre- orientation of the anal opening. In pentabrachiate Permian pentabrachiate genera typically are pre- Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 9 served without oral plates, since the latter do not stem, and an anal opening below the top of the form an integral part of the theca, but apparently radial circlet. As pointed out previously, some are loosely articulated so that they tend to fall off primitive codiacrinaceans have five unfused infra- soon after death of the crinoid. All abrachiate basais and all lack peripheral canals in the stem forms typically have the orals preserved in place. and axial canals in the radials and brachials; also, The combination of morphologic features dis- codiacrinaceans with an anal opening below the cussed—number of arm-bearing radials, number top of the radials are not found until Mississippian pres- of infrabasals, position of anal opening, and time, indicating that this characteristic was devel- ervation of oral plates—supports the hypothesis oped independently in the two groups of crinoids. that three separate, distinctive, long-continued phy- Consequently, the gasterocomids and codiacrina- logenetic lines were developed within the crinoids ceans are judged not to be closely related. previously classed in the family Codiacrinidae. A literature search for a potential pre-Middle Consequently, it is judged desirable to recognize Devonian ancestor for all of the Codiacrinacea re- order each of these groups as a separate family in veals that only the Silurian palaeocrinid Thalamo- these crinoids. to effect a phyletic classi fication of crinus possibly qualifies as an ancestral type. This genus consists of small individuals with a rela- ANCESTRY OF CODIACRINACEANS tively high theca, five infrabasals, large basal two anal It has been postulated that the codiacrinaceans plates, five small arm-bearing radials, and were expelled evolved from, or had a common ancestor with, the plates in the cup. If the anal plates fused into three Gasterocomidae (MooRE & LAUDON, 1943). This from the cup and infrabasals Codiacri- relationship can no longer be supported, especially plates, Thalamocrinus would resemble If in view of more recent knowledge of oldest known nus, the oldest pentabrachiate codiacrinacean. were (Devonian) Codiacrinacea. The gasterocomids are two of the radials disappeared and one anal genus would resemble a group of Silurian and Devonian genera charac- eliminated, the former to terized by such specialized features as a completely Streblocrinus, which is judged to be ancestral fused infrabasal circlet, peripheral canals in the the abrachiate types.

SUPRAGENERIC CLASSIFICA TION OF CYATHOCRININA Order CLADIDA Moore & Laudon, 1943 dendro- and poteriocrinoids. The cyathocrinita- ceans possessed an anal sac, like all more advanced Suborder CYATHOCRININA Bather, cladid crinoids, but the sac is short, confined to 1899 the posterior part of the tegmen, and is composed Superfamily CYATHOCRINITACEA of heavy, imperforate plates with a terminal anal porous or reflexed sac, or one with a Bassler, 1938 (Roemer, 1854) opening. A wide spinose cap was not developed. Most of the LANE, herein (ex Cyathocriniticlue BASSLER, [nom. transi. in the superfamily have isotomous arms 1938) (RoEmER, 1854)] genera with relatively numerous branches; only the Bary- bowl-shaped; radianal small Diagnosis.—Theca crinidae have heterotomously arranged branchlets, or absent; anal-X large; one or more additional suggesting a trend toward pinnulation. These may be in cup. Tegmen produced into anal plates crinoids show another trend parallel to those of anal sac with terminal anal opening. Arms stout more advanced cladids in having radial facets rela- or many branches, or atomous, isotomous with few tively wider than in most other Cyathocrinina and heterotomous. the facet may develop an obscure transverse ridge Families.—Cyathocrinitidae BASSLER, 1938 in advanced types. (RoEmER, 1854); Ampheristocrinidae S. A. MIL- 1934; Barycrini- LER, 1890; Lecythocrinidae KIRK, Superfamily PALAEOCRINACEA dae JAEKEL, 1918. Remarks.—The Cyathocrinitacea are judged to Bather, 1899 comprise an advanced stock of families that de- [nom. transi. LANE, herein (ex Palaeocrinidae BATHER, veloped several morphologic features paralleling 1899)] and the more successful evolutionary trends of the Diagnosis.—Theca bowl-shaped; radianal

10 The University of Kansas Paleontological Contributions—Paper 24

monocyclic group mainly in the possession of in- frabasals. The Carabocrinidae are the only inadu- nate crinoids having a double radianal plate, with upper and lower parts caller super- and inferradi- 36.ct- anal. The Palaeocrinidae have a single radianal and atomous arms, in contrast to the isotomously divided arms of the carabocrinids. The three fam- \7Hemistreptacron ilies which are judged to have evolved directly from palaeocrinids are highly specialized, short- lived Silurian and Devonian crinoids characterized by a low, bowl-shaped cup, and isotomously branched arms. In the Gasterocomidae the anal opening has migrated downward into the posterior side of the cup to a position just above the poste- rior basal. The stem is distinctive in having three or four peripheral canals surrounding the main axial canal. The Petalocrinidae have no anal plates in the cup and the brachials of each ray are fused into a single solid plate with branching ambulac- ral canals on the ventral surface of each ray plate. The Crotalocrinitidae have many-branched arms with brachials laterally joined to form a flexible 9. meshwork. All three of these families have sepa- 5:7„97 Dichostreblocrinus rate axial canals piercing the radials and brachials. N./ Lampadosocrinus Superfamily CODIACRINACEA Bather, 1899 Su bfamily Subfamily [nom. transi. LANE, Pentececrininae Streblocrininae herein (ex Codiacrinidae BATHER, 1899)] FIG. 8. Different modes of anal opening and oral relation- Diagnosis.—Theca small, radials five, three, ship in subfamilies Pentececrininae and Streblocri- one, or absent. Radianal absent, anal-X present ninae of the family Streblocrinidae. Line beneath only primitively each oral rosette represents the posterior basal. or secondarily. Tegmen low, com- posed of five orals, posterior one large, separating BC and DE orals, commonly with hydropore, anal-X present, or one or both may be absent; or rarely and secondarily developed infer- and superradianal present primitively. Teg- as madreporite. Dev.-Perm. men low, flat, anal opening directly through teg- Families.—Codiacrinidae BATHER, 1899; Syco- men or side of cup; posterior oral with hydropore crinitidae LANE, n.fam.; Streblocrinidae LANE, n. or developed as madreporite. Arms atomous or fam. isotomous; brachials fused in each ray, or laterally united in specialized families. Ord.-Dev. Family CODIACRINIDAE Bather, 1899

Families.—Palaeocrinidae BATHER, 1899; Cara- [ -, Hypocrinidae JAEK EL, 1918; Embryocrinidae WANNER, bocrinidae BATHER, 1899; Crotalocrinitidae BASS- 1916] LEE, 1938 (pro Crotalocrinidae ANGELIN, 1878); Diagnosis.—Codiacrinoids with five facet-bear- Petalocrinidae WELLER & DAVIDSON, 1896; Gas- ing radials, or rarely with five secondarily reduced, terocomidae ROEMER, 1854. nonfacet-bearing radials of equal size. Anal open- Remarks.—The Palaeocrinidae and Carabocri- ing between radials and basais, or radials and orals. nidae are the oldest and structurally most primi- Anal-X absent, or secondarily developed above or tive of the Cyathocrinina. Both families have egg- below anal opening in advanced genera. Posterior shaped thecae reminiscent of the monocyclic dis- oral with a hydropore or developed as a madre- parid suborder Hybocrinina, differing from that porite. Dev.-Perm. Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 11

Subfamilies.—Codiacrininae BATHER, 1899; and its anal opening, instead of being directly Bolbocrininae WANNER, 1916; Thetidicrininae above the posterior basal, has shifted to the right, WANNER, 1916. indenting the upper right shoulder of the posterior oral next to the C radial. The position of the anal Subfamily CODIACRININAE Bather, 1899 opening in this genus is comparable to that of the [nom. transi. LANE, herein (cx Codiacrinidae BATHER, Clistocrinus, but 1899)] [.=_Hypocrininae WANNER, 1929; section Hypo- Pennsylvanian abrachiate genus crinites WANNER, 1929] the presence of radials and arms in Tenagocrinus of the two Diagnosis.—Codiacrinids that lack madreporite is thought to preclude any relationship and anal-X. forms. Genera.—Codiacrinus SCHULTZE, 1866; Cydon- Subfamily BOLBOCRININAE Wanner, 1929 WANNER, ocrinus BATHER, 1913; Abrachiocrinus [nom. transi. LANE, herein (ex section Bolbocrinites 1920; Lecythiocrinus WHITE, 1879 (=Menocrinus WANNER, 1929)] S. A. MILLER, 1889); Amphipsalidocrinus WEL- Diagnosis.—Codiacrinids with anal opening in LER, 1930; Hypocrinus BEYRICH, 1862; Cranocri- side of cup, bounded above or below by secondarily nus WANNER, 1929; Tenagocrinus WANNER, 1929; developed anal plate; without madreporite. Asymmetrocrinus Embryocrinus WANNER, 1916; Genera.—Bolbocrinus WANNER, 1916; Nereo- WANNER, 1937. crinus WANNER, 1924 (=Oceanocrinus WANNER, Remarks.—The central evolutionary stock of 1924). this subfamily is judged to be one that includes Remarks.—The two genera of this subfamily Codiacrinus (Dev.), Cydonocrinus (L.Carb.), Le- are closely related, differing mainly in whether the cythiocrinus (Penn.), and Hypocrinus (Perm.). anal plate is above (Nereocrinus), or below (Bolbo- These genera show trends for the anal opening to crinus) the anal opening. The presence of an extra migrate from the tegmen down into the side of plate in the posterior interray is thought to be a the cup (Codiacrinus to Cydonocrinus), and grad- secondary, advanced development, not a holdover ual reduction in size of the radials, resulting in from a more primitive condition. All post-Devo- change of cup form from an essentially conical nian, pre-Permian codiacrinids except Edapocrinus shape in Codiacrinus to an egg-shaped theca in (an unusual, specialized Lower Carboniferous Hypocrinus. In this main evolutionary line the form), lack any trace of an anal plate in the theca. anal opening is persistently above the posterior Development of an extra plate in the posterior basal, and oral plates are not preserved above the part of the theca may be related to a tendency for radials. During Early Carboniferous time the the radial plates to decrease in size in Permian aberrant Abrachiocrinus developed, which has five Codiacrinidae, and the resultant necessity for fill- subequal radials that lack articular facets. A form ing up of space around the anal opening. There like this genus may have led to the Permian genus is no indication that the anal plate of the Bolbo- Embryocrinus, which differs from it mainly in crininae is homologous with the anal-X, radianal, having the armless radials reduced to the point or right tube plate of most inadunate crinoids. where they are completely separated by basais and orals. Subfamily THETIDICRININAE Wanner, 1929 Hypocrinus is judged to have been the rad- [nom. transi. LANE, herein (ex section Thetidicrinites icle from which the Bolbocrininae and Permian WANNER, 1930)] genera of the Thetidicrininae evolved. Other off- Diagnosis.—Codiacrinids with madreporitic shoots from Hypocrinus include Cranocrinus, with posterior oral, and one or two anals in dorsal cup. completely fused infrabasals and asymmetrically Genera.—T hetidicrinus WANNER, 1916; Pro- arranged facets on the radials, Asymmetrocrinus, choidiocrinus WANNER, 1937; Edapocrinus which has five infrabasals and radials and radial WRIGHT, 1935 [=Edaphocrinus WANNER, 1937 facets of quite unequal size, and Tenagocrinus, (nom van.)]. the only Permian codiacrinid for which the arms Remarks.—This subfamily is clearly polyphy- are known. This genus has five small triangular letic, for there is little reason to assume that the radials completely separated from each other by two Permian genera described by WANNER evolved basais, as in Embryocrinus, but unlike that genus, from the only known Lower Carboniferous genus Tenagocrinus possesses five atomous uniserial arms Edapocrinus. The latter differs from most codia- 12 The University of Kansas Paleontological Contributions—Paper 24 crinids in having a flat base, with infrabasals hid- Both of the genera just mentioned differ from den in side view, relatively large radial facets, and Metasycocrinus in having radials that are approxi- more than five plates in the tegmen. The five mately of equal size, although the arm-bearing D orals are large, interradial plates, of which the pos- radial is consistently the largest plate of the circlet. terior one is pierced by numerous canals to form In Metasycocrinus the C radial is reduced to small a typical madreporite. The summit of the tegmen size, and the anal opening scallops the tops of both is covered by five small tegminal plates which al- the posterior and BC basais. In Monobrachiocri- ternate with the orals, so as to be situated radially. nus, clearly a descendant of Parasycocrinus, the WRIGHT called these plates epiorals. Several small anal opening is in the same position but all of plates surround the anal opening, located on a the radials except the arm-bearing D radial have slightly protuberant part of the posterior side of disappeared. the cup. This projection is not sufficient to war- rant designation of it as an anal sac in the usual Family STREBLOCRINIDAE Lane, new family sense. Edapocrinus is judged to have evolved from Diagnosis.—Codiacrinaceans with no arm-bear- a form like Cydonocrinus by fusion of the infra- ing radial plates; radials absent in all but most basais into a single plate and development of the primitive genus; anal plate absent in all post- characteristic features discussed. The two Per- Devonian genera; orals five, large, posterior oral mian genera are thought to have evolved from a commonly with hydropore and separating BC and generalized Permian form like Hypocrinus by de- DE orals. Orals primitively above basais and anal velopment of one or two accessory anal plates be- opening is on the lower right side of posterior low the anal opening, a madreporitic posterior basal. Dev.-Perm. oral, and in Prochoidiocrinus, fusion of three inf ra- basals into a single plate. Subfamily STREBLOCRININAE Lane, new subfamily Anal opening shifted toward left of anteropos- Family SYCOCRINITIDAE Lane, new family terior axis and orals uniformly rotated clockwise Diagnosis.—Codiacrinaceans with one arm- to a radial position. Dev.-Perm. bearing radial, other radials present or absent, This subfamily is represented in the Middle commonly unequal and reduced in size; three in- Devonian by Streblocrinus and Tytthocrinus, the frabasals; anal plate absent; anal opening bounded latter an unusual codiacrinacean that lacks radials, by basais and radials or by radials. Orals small, has five orals but only three basais and infrabasals. commonly not preserved. L.Carb.-Perm. Tytthocrinus ranges into the Pennsylvanian and Genera.—Sycocrinites AUSTIN & AUSTIN, 1842 is thought to be a specialized offshoot of the (=Sycocrinus BATHER, 1900); Allosycocrinus Streblocrininae that did not lead to any other gen- WANNER, 1924; Metasycocrin us WANNER, 1920; era. Streblocrinus, on the other hand, has several Monobrachiocrinus WANNER, 1916; Paras ycocrinus morphologic features which indicate that it may MARLZ OYENS, 1940. be close to an ancestral type for all other, younger, Remarks.—This group of genera is thought to genera in the family Streblocrinidae. There are be closely related and to represent a single phyletic five infrabasals, five large basais, and three small lineage even though no Pennsylvanian representa- triangular radials that lack articular facets. These tives have been found. The major difference be- radials are in the A, C and D rays. Five large tween Lower Carboniferous Sycocrinites and Per- orals surmount the basais, and although the only mian Allosyocrinus is in the position of the anal known specimen is imperfect in the posterior area, opening, which is directly above the posterior a single anal plate is thought to be present below basal in the older form and notches the top of one and at left of the D radial. Whether this plate was of the radials in the younger. Although the small anal-X or a radianal is not known. By loss of the infrabasal is in a different position in these two three radials, Streblocrinus leads to the Pennsyl- genera, being in the C radius in Sycocrinites and vanian genus Dichostreblocrinus, which ranges in the D radius in Allosycocrinus, this difference into the Permian. Two other abrachiate genera is thought not to be of generic importance, consid- found in the Permian appear to have evolved from ering the variation in position of the small infra- Dichostreblocrinus, which differs from its Devo- basal in other genera of the Codiacrinacea. nian predecessor, Streblocrinus, mainly in having Lane—Revision of Suborder Cyathocrinina (Class Crinoidea) 13 the orals uniformly shifted about 9 0 to the left of tion directly above the basais. A single anal plate the basais. In the Permian there is a clear trend is inserted within the basal circlet between the for the position of the anal opening to shift to the upper right corner of the posterior basal and up- left, until in Coenocystis it notches the upper left per left corner of the right posterior basal. In the corner of the posterior basal and is in the mid-line next succeeding Mississippian genus Lampadoso- of the posterior oral (Fig. 7). The shift in posi- crinus, expansion of the left side of the posterior tion of the anal opening is accompanied by a uni- oral indicates the beginning of a trend in which form rotation of the oral plates to the left until in the oral plates shift to a radial position and the Coenocystis they occupy a radial position, having anal opening moves to the mid-line of the posterior rotated 12 ° to 20° in Hemistreptacron to 36° in basal (Fig. 7). This trend culminates in the Per- Coenocystis. Except for Streblocrinus, all of the mian genus Acariaiocrinus. Except for Pentece- genera in this subfamily have fused infrabasals. crinus and Lam padosocrinus, which have five in- Genera.—Streblocrinus KOENIG & MEYER, frabasals, all other genera in this subfamily have 1965; Dichostreblocrinus WELLER, 1930; Hemi- three. streptacron YAKOVLEV, 1926; Coenocystis GIRTY, Genera.—Pentececrinus KOENIG & NIEWOEHN- 1908; Tytthocrinus WELLER, 1930 (=Octocrinus ER, 1959; Lampatiosocrinus STRIMPLE & KOENIG, PECK, 1936); Atremacrinus WANNER, 1929; pai- 1956; Lageniocrinus DE KONINCK, 1854; Clistocri- diocrinus WANNER, 1937. nus KIRK, 1937 (=Clithrocrinus KIRK, 1937, nom. van.); Acariaiocrinus WANNER, 1924 (=Strepto- Subfamily PENTECECRININAE Lane, new subfamily stomocrinus YAKOVLEV, 1927). Anal opening shifted secondarily to anteropos- terior axis and orals moved to a radial position by ACKNOWLEDGMENTS left-lateral extension of the posterior orals. Dey.- The author is indebted to RAYMOND C. MOORE Perm. for critical review of this paper, and to JOHN W. Pentececrinus, a Late Devonian genus judged KOENIG, Missouri Geological Survey, who sug- to be a direct descendant of Streblocrinus, is a gested several substantial changes in treatment of primitive streblocrinid possessing five infrabasals, the Streblocrinidae which are reflected in both the five large basais, and five orals in interradial posi- text and illustrations concerning this family.

REFER ENCES

BATHER, F. A., 1899, A phylogenetic classification of the STRIMPLE, H. L., & KOENIG, J. W., 1956, Mississippian Pelmatozoa: British Assoc. Rept., 1898, p. 916-923. microcrinoids from Oklahoma and New Mexico: Jour. Kum, EDWIN, 1940, A redescription of Lageniocrinus de Paleontology, v. 30, p. 1225-1247, fig. 1-4. Koninck: Am. Jour. Sci., v. 238, p. 129-139, fig. 1-12. UBAGHS, GEORGES, 1953, Classe des Crinoïdes: in Traité de paléontologie, Jean Piveteau (ed.), v. 3, p. 658-733, 166 KOENIG, J. W., & MEYER, D. L., 1965, Two new crinoids from the Devonian of New York: Jour. Paleontology, v. fig. WANNER, JOHANNES, 1929, Nette Beitriige ZUr Kenntnis der 39, p. 391-397, fig. 1-4. permischen Echinodermen von Timor, II, Hypocrinites: & NIEWOEHNER, WALTER, 1959, Pentececrinus, a Dienst van den Mijnb. Neder1.-Indié, Wetenschap. new microcrinoid from the Louisiana Formation of Medel. no. 11, 116 p., 16 fig., 7 pl. Missouri: Same, v. 33, p. 462-470, 3 text-figs. WELLER, J. M., 1930, A group of larvi form crinoids from MOORE, R. C. & LAUDON, L. R., 1943, Evolution and classi- Lower Pennsylvanian strata of the Eastern Interior fication of Paleozoic crinoids: Geol. Soc. America Spe- basin: Illinois Geol. Survey, Rept. Investig., no. 21, 38 cial Paper 46, x+167 p., 18 fig., 14 pl. p., 2 pl. PECK, R. E., 1936, Lower Mississippian microcrinoids from YAKOVLEV, N. N., 1928, Sur la teratologie et la morpho genie the Kinderhook and Osage Groups of Missouri: Jour. des crinoïdes abrachiates: Acad. Sci. U.R.S.S., Comptes Paleontology, v. 10, p. 282-293, pl. 46-47. Rendus, no. 16-17, p. 313-315, fig. 1-3.