Fig. 14b. Skeleton of Mazonerpeton costatum Moodie. × 1.5. Original in Yale University Museum, dv, dorsal vertebra; ch, neutral spines; cl, clavicle; cv, caudal vertebræ; f, femur: h, humerus; m, mandible; rb, rib; sk, skull; v, vertebræ.
The part of the skull preserved is very unsatisfactory and, aside from the fact that it seems to represent the under side of the left half of the skull, little can be said. Three sutures can be observed, but what sutures they are is undetermined. The left mandible lies crushed on the edge of the skull and partially obscures what little there is of that structure. The slightly curved impression, from which the bone has been either broken or weathered, measures 13 mm. in length by 3 mm. in posterior diameter by 1 mm. in anterior diameter. These measurements show the element to have been slender and pointed anteriorly.
Very little accurate information can be derived from the study of the vertebral column of the specimen, nor can the dorsal vertebral formula be made out, since only a portion of the length of that region is preserved and only a few rather indefinite impressions can be discerned. These impressions show the vertebræ to be short and higher than in most Branchiosauria.
The caudal series is represented by two sections, one of which is, apparently, from near the base of the tail, judging from the size of the caudal ribs preserved; the other is from near the tip of the tail, and shows the constituents to have been long and slender. Ribs are apparently absent on this section. The position of the two caudal sections shows that when the animal died it was coiled up much like a snake, so that in the fractured nodule three sections of the body are visible. The tail was probably half as long again as the body.
The ribs throughout the body are short, heavy, and straight, with, in the dorsal series, a lateral and a distal expansion which is taken as a distinctive specific character. Judging from imperfect impressions in the dorsal series, the ribs were attached to a transverse process of the centrum, thus agreeing with other branchiosaurians in this respect. The ribs show a progressive decrease in length from the cervical region to the point of their disappearance on the tail.
MOODIE
1. A reconstruction of the possible appearance in life of the Coal Measures branchiosaurian, Eumicrerpeton parvum Moodie, a small, primitive salamander, less than 2 inches in length, based on three specimens from the Mazon Creek Shales. The lateral-line organs are represented as dark bands on the tail, the sense-organs being, apparently, situated beneath specialized pigmented scales, to which is due the preservation of the lines.