THE AMPHIBIA 93 



of these were only a few inches long, but a few such 

 as Eogyrinus (see Figure 8) reached a length of fifteen 

 feet, and one, Onychopus gigas, which has left us only 

 its footprints, had a stride of thirty inches and is esti- 

 mated to have weighed six hundred pounds. Most of the 

 Carboniferous Amphibia were, however, small salaman- 

 derhke creatures with a well-developed tail (the tailless 

 frog is highly speciahzed for jumping), and they moved 

 by twisting the body in fishlike motions, using the legs 

 as pivots and letting the tail drag on the ground. Micro- 

 hatrachus and Miohatrachus, only a few inches long, 

 were apparently ancestral to surviving forms. (Some cen- 

 turies ago a large fossil salamander closely related to the 

 living hellbender, Crypt obranchus, was recovered from 

 Miocene deposits near Lake Constance and was identi- 

 fied as the remains of a poor human sinner drowned in 

 the Flood, and called Homo diluvii testis. This precise 

 relationship is far off the mark, but the ancestors of this 

 salamander do stand in the line of man's descent. ) 



By the Permian the Amphibia had become better 

 adapted to life on land: Eryops, five feet in length, had 

 short but powerful legs, and Cacops, only sixteen inches 

 long, was armored with dermal plates along the back, 

 presumably as a defense against the carnivorous reptiles 

 which had then become abundant. Seyrmmrui, from the 

 Lower Permian red beds of Texas, reached a length of 

 twenty inches and stands close to the ancestral hne of 

 the reptiles and mammals, and it may have laid a shelled 

 egg on dry land. 



The Amphibia were, however, neither fish nor good 

 red flesh. With the possible exception of Seymouria, they 

 continued to lay their fishlike, naked eggs in shallow wa- 

 ter or in moist places, and the young hatched in the 

 form of fishlike larvae with fishlike gills, to spend the 

 first part of their life in water, only later metamorphos- 

 ing into the adult form under the endocrine control of 

 the pituitary and thyroid glands. As larvae, they proba- 

 bly fed on small aquatic plants and animals; as adults. 



