2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



SYSTEMATIC DESCRIPTION 

 EOSAURAVTJS COPEI Williston 

 Plate i ; Text Figures 1-3 



Isodcctes punctulatus Cope, Proc. Amer. Philos. Soc, vol. 36, pp. 88-90, pi. 3, 

 fig. 3, 1897; Williston, Journ. Geol., vol. 16, pp. 395-4°°, text fig. 1, pi. 1, 

 1908; Moodie, Proc. U. S. Nat. Mus., vol. 37, pp. 11-16, pis. 4-5, 1909. 



Eosanravus copci Williston, Bull. Geol. Soc. Amer., vol. 21, p. 272, 1910; Case, 

 Carnegie Inst. Washington Publ. 145, pp. 3I-3 2 , text fig. 8, 1911. 



Tuditanus punctulatus Romer, Bull. Amer. Mus. Nat. Hist., vol. 59, pp. 134-135, 

 1930; Bull. Mus. Comp. Zool., Harvard Coll., vol. 99, p. 300, 1947; Amer. 

 Journ. Sci., vol. 248, p. 641, 1950; Huene, Palaontologie und Phylogenie der 

 niederen Tetrapoden, p. 163, 1956. 



f Tuditanus Romer, Osteology of the reptiles, p. 483, 1956. 



Type. — U.S.N.M. No. 4457 ; posterior § of a reptilian skeleton pre- 

 served belly-down on a slab of coal from Linton, Ohio. 



Horizon. — Allegheny group, Middle Pennsylvanian (Westphalian). 



Diagnosis. — Small reptile with a minimum of 28 presacral vertebrae 

 of generally captorhinid structure, with broad, swollen neural arches, 

 low neural spines, zygapophyseal facets in horizontal plane, and small 

 intercentra ; free ribs on all vertebrae except distal caudals ; distal 

 caudal vertebrae with low neural arches and probably without haemal 

 spines, centra occasionally fused forming relatively stiffened axis ; 

 one principal and one accessory sacral rib ; hind limb with prominent 

 internal trochanter, with relatively short epipodial (=zeugopodial) 

 segment having relatively massive fibula; primitive, well-ossified 

 tarsus of basic captorhinid or pelycosaurian plan with separate median 

 and lateral centrale and with a 6th distal tarsal ( =postminimus) ; 

 phalangeal formula 2-3-4-5-4, terminal phalanges blunt-ended. No 

 gastralia present; possibly with body scales, having striae radiating 

 from anterior margin of scale. No obvious aquatic adaptations of 

 well-ossified skeleton. Anterior skeleton unknown. 



Taxonomic notes. — The taxonomic history of Cope's specimen is so 

 devious and confusing that a short explanation is necessary to sup- 

 plement the synonymy listed above. Cope (1897) described the 

 posterior skeleton and believed it to be conspecific with another small 

 vertebrate represented by a skull and anterior two-thirds of a skeleton. 

 The latter had been described by Cope (1874, p. 271) as Tuditanus 

 punctulatus, but in his 1897 paper, it was referred along with the 

 posterior skeleton to the genus Isodectes. Williston (1908) and 

 Moodie (1909) offered new descriptions of the posterior skeleton, 

 treating it as distinct from the anterior skeleton, but tending to over- 

 look the fact that the anterior skeleton is the type of Isodectes 



