| Measurements of the Type of Amphibamus thoracatus Moodie. (No. 4306, U. S. National Museum.) | |
| mm. | |
| Length of entire specimen, as preserved | 60 |
| Length of skull impression | 18 |
| Greatest width of same | 15.5 |
| Long diameter of right orbit | 4 |
| Transverse diameter of same | 3 |
| Transverse width of interclavicle | 14 |
| Long diameter of same | 7(?) |
| Long diameter of clavicle | 9 |
| Greatest transverse diameter | 3 |
| Length of humerus | 10 |
| Greatest diameter of same | 4 |
| Least diameter of same | 1.5 |
| Length of radius (ulna?) | 11 |
| Length of vertebral centrum | 2 |
| Width of same | 3 |
Moodie, Kans. Univ. Sci. Bull., VI, No. 2, p. 340, 1912.
Type: Cephalerpeton ventriarmatum Moodie.
This genus is founded on remains of a nearly entire individual of a relatively large microsaurian from the Mazon Creek shales. The genus is most immediately related to the Amphibamidæ, of which two species are already known, Amphibamus grandiceps Cope and A. thoracatus Moodie. The present genus differs from these species in many respects, notably in size. The skull in Cephalerpeton is nearly as long as half the entire body of Amphibamus grandiceps Cope, inclusive of the tail. Other structural differences are the anisodont teeth, the large size and the more median position of the orbits, and the absence of the posterior tympanic notch in Cephalerpeton. The form of the skull recalls that of Melanerpeton and Pelosaurus ([190]) of Europe, but those genera are branchiosaurian, while the present form, from the structure of the vertebræ and the long, curved ribs, is an undoubted microsaurian. Nothing like it occurs in any of the amphibian faunas thus far made known. It is most nearly approached by a member of the genus Erpetosaurus, but from this genus the present form is readily distinguished by the smooth skull bones, the absence of a posterior table to the skull, and the presence of a highly developed ventral armature. The interorbital width is less than the transverse diameter of the orbit.
MOODIE
1. Type specimen of Erpelosaurus sculptilis Moodie, from the Cannelton Shales of Pennsylvania. Original in the University of Chicago, Walker Museum.
2. Skeletal elements of Eryops sp. indet., from the Pittsburgh Red Shale at Pitcairn, Pennsylvania. a=nearly complete vertebra; b and c=ribs; d=pleurocentrum; f=neural arch and spine. Originals in the Carnegie Museum at Pittsburgh. After Case.