AMERICANt MUSEUM Novltates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2774, pp. 1-20 January 27, 1984 Studies on the Paleozoic Selachian Genus Ctenacanthus Agassiz. No. 3. Nominal Species Referred to Ctenacanthus JOHN G. MAISEY' ABSTRACT All known nominal species of the Paleozoic another spine genus, Acondylacanthus; three are chondrichthyan genus Ctenacanthus are listed, to- referred to Asteroptychius; nine are referred to gether with information concerning provenance, Sphenacanthus; 20 are referred to various other whereabouts of type material (where known), im- genera; eight are considered close to Ctenacanthus portant subsequent references and comments on but are excluded from it; and 23 are left in Cten- the probable affinities of each species. Other ref- acanthus. Of the latter, however, eight are prob- erences to undetermined Ctenacanthus spp. are ably synonyms of the type species, C. major, and listed chronologically. Ofsome 100 species, 10 are consequently only 15 species are retained. Ofthese, considered totally invalid; the holotypes of five seven are from the Upper Devonian and eight are others are known to be lost or destroyed; four from the Lower Carboniferous; all are from marine others are founded on inadequate material; 10 are strata. This stratigraphic range is much less than referred to the Acanthodii; eight are referred to the previous records have suggested. INTRODUCTION In the two preceding parts of this series future. In the meantime, it seems advisable (Maisey, 1981, 1982), the diagnosis of Cten- to publish a compilation of data concerning acanthus has been refined to agree with the prior references to Ctenacanthus finspines. type species, C. major, and a list of species The checklist and references given below rep- founded on finspines similar to those of C. resent the majority ofpublished accounts. Al- major has been published. Certain other fin- though I have tried to make this list as com- spines, differing strongly from those of C. plete as possible, perhaps it is inevitable that major, were referred to various genera in part a few sources have escaped notice. Never- two of these studies. Many additional forms theless, no similar listing has been compiled remain to be surveyed, and it is hoped that since the publication of the second volume some of these will be reviewed in the near of Woodward's (1891) Catalogue, and the ' Assistant Curator, Department of Vertebrate Paleontology, American Museum of Natural History. Copyright © American Museum of Natural History 1984 ISSN 0003-0082 / Price $1.70 2 AMERICAN MUSEUM NOVITATES NO. 2774 present compilation may therefore be useful Ctenacanthus abnormis Giebel (1858, p. 264, to paleontologists, zoologists, and biostratig- pl. 1, fig. 12). raphers. Where the location of a type speci- Lower Devonian, Harz Mountains. men is known, it is given, together with its COMMENTS: See also Barrande (1872, p. catalogue number. Where this datum is ab- 628), Kayser (1878, p. 3, Taf. 1, fig. 19). Re- sent, the whereabouts of the type material is ferred to Machaeracanthus by Woodward unknown (although this does not necessarily (1891, p. 123). mean that it is lost, only that I have not been able to locate it). In order to increase the Ctenacanthus acutus Eastman (1897), p. 12, usefulness ofthe data, notes have been added fig. 2). after each species is listed, and the affinities Type specimen, USNM 4683; Mississip- and validity of the species are discussed. pian, Keokuk Limestone, Iowa. Species of Ctenacanthus are listed in alpha- COMMENTS: Another specimen, USNM betical order, and are followed by a list of 4682 may be referred to this species. In trans- indeterminate references to "Ctenacanthus verse section and ornamentation pattern C. sp." acutus finspines resemble those of Tristy- I stress that, while many species have been chius. USNM 3480 said to be close to C. referred to Ctenacanthus, only a small num- acutus (Eastman, 1902, p. 83). ber are based on finspines that compare Ctenacanthus aequistriatus Davis (1879a, p. closely with the type species. Many of the 185, pl. X, fig. 5). species herein have subsequently been re- Lower Coal Measures (Pennsylvanian), ferred to other genera, and probably even Yorkshire, England. more of them will be removed as work pro- COMMENTS: This form was subsequently gresses. The reader is cautioned here, and is referred to the genus Sphenacanthus by reminded in text, that some of these spines Woodward (1889, p. 244) and Maisey (1982). may pertain to very different fishes from Ctenacanthus amblyxiphias Cope (1891, p. Ctenacanthus. For diagnoses and discussions 449, pl. XXVIII, fig. 3). of the genus, the following are the main Type 7289, Permian, sources: Agassiz (1837), McCoy (1855), New- specimen, AMNH Davis Texas. berry (1873), De Koninck (1878), COMMENTS: Other references include East- (1883), Woodward (1891), Eastman (1902, man (1903), Woodruff (1906), Hussakof 1907), Obruchev (1967), Maisey (1981, (1908, 1911), Branson (1916), Romer(1942), 1982). Wells (1944), Berman (1970), and Zidek INSTITUTIONAL ABBREVIATIONS (1976). According to Wells (1944), however, AMNH, American Museum of Natural History Eastman's (1903) finspine is closer to that of BM(NH), British Museum (Natural History) C. lamborni; this is also the case with Bran- CNIGR, Central Scientific Research, Geological son's (1916) specimen. Prospecting Museum, Leningrad MCZ, Museum ofComparative Zoology, Harvard Ctenacanthus angulatus Newberry and Wor- University then (1866, p. 118, pl. XII, fig. 4). USNM, National Museum of Natural History, Type specimen, University of Illinois Smithsonian Institution, Washington, D.C. X- 1152, Mississippian, Chester Limestone, YPM, Yale Peabody Museum Chester, Illinois. ALPHABETICAL LIST OF SPECIES COMMENTS: There are similarities between C. angulatus and C. similis finspines, but All the following species have been referred these are not sufficient to suggest synonymy. to Ctenacanthus, in most cases by the original Ctenacanthus angulatus is among the species author, but occasionally by a subsequent one. retained in the genus by Maisey (1981). The name is given, followed by the author, reference date, page and illustration num- Ctenacanthus angustus Newberry (1889, p. bers. If known, the type specimen is listed, 181). with locality data if any. Additional data are Type specimen, AMNH 5269, "Subcar- then given under Comments. boniferous," Berea Grit, Berea, Ohio. 1984 MAISEY: CTENACANTHUS AGASSIZ 3 COMMENTS: The type was not figured by Ctenacanthus and referred instead to Bythi- Newberry (1889) but the specimen so des- acanthus by Maisey (1981, 1982). Several ignated bears a label in his handwriting. A other specimens were listed by Woodward detail of its ornament was subsequently fig- (1891, p. 100), who noted that C. limaformis ured (Hussakof, 1908, fig. 19). The species is is probably synonymous with this species. among those retained in the genus by Maisey (1981). Some specimens referred to "C. an- Ctenacanthus browni Branson (1916, p. 653, gustens" e.g., BM(NH) P9581, P9262, may pl. IV, fig. 7, text fig. 6). pertain to this species. Type specimen, University ofMissouri no. 709, Upper Carboniferous, Embar Forma- Ctenacanthus bellus Branson (1906, p. 1393, tion, Wyoming. pl. XLII, figs. 19-21). COMMENTS: An additional specimen was Syntypes, AMNH 6446 (two pieces), Mis- referred to the species by Branson (1933). sissippian, Salem Limestone, Lanesville, In- The finspine was not included in Ctenacan- diana. thus by Maisey (1981); it is more probably COMMENTS: This species is not referable to allied to Acondylacanthus. Ctenacanthus. The wedge-shaped transverse section, tubercles toward the leading edge, Ctenacanthus burlingtonensis St. John and and presence of a narrow median ridge pos- Worthen (1875, p. 426, pl. XV, figs. 6, 7). teriorly characterize this as an Asteroptychius Cotypes, USNM 13523 and 13524, Mis- finspine. sissippian, St. Louis Limestone, St. Louis, Missouri. Ctenacanthus bohemicus Barrande (1872). COMMENTS: An additional specimen, Lower Devonian (Siegenian), Lochkov AMNH 1031, seems close to the type ma- Limestone (Bohemia), Taunusquartzit terial in many respects. The fragments upon (Rheinland). which this species is based are remarkably COMMENTS: Referred to Machaeracanthus similar to finspines of Acondylacanthus gra- by Woodward (1891, p. 124), Fritsch (1895, cillimus. Probably C. burlingtonensis is syn- p. 72), and Denison (1979, p. 52); probably onymous with C. gradocostus. an acanthodian. Ctenacanthus buttersi St. John and Worthen Ctenacanthus bosnensis Katzer (1916, p. 201, (1883, p. 240, pl. XXII, fig. 2). Tab. 1, figs. 1-13), Pennsylvanian, Lower Coal Measure, Car- Triassic, near Sarajevo, Bosna i Hercego- linville, Illinois. vina, Yugoslavia. COMMENTS: The ornamentation ofthe type COMMENTS: This species is probably refer- specimen differs from that of Ctenacanthus able to Nemacanthus. Its finspines are char- finspines. The general shape and the arrange- acteristically ornamented with longitudinal ment ofthe ornament in C. buttersi are rem- series of rounded tubercles laterally and an iniscent ofMesozoic hybodont finspines. This enameled keel anteriorly. form does not seem close to Sphenacanthus. A spine from the Seminole Formation of Ctenacanthus brevis Agassiz (1837, vol. III, Oklahoma was said to be reminiscent of C. p. 11, table 2, fig. 2). buttersi by Zidek (1977, p. 153). Type specimen, Bristol City Museum "Ctenacanthus buttlersi St. John