The third line of progress leads to some slender and beautiful creatures (Microsauria), chiefly known to us by remains found in erect trees, and which resembled in form and habits the smaller modern lizards. They have simple teeth, a well-developed brain-case, limbs of some length, and bony and scaly armour, the latter in some cases highly ornate.[60] They were probably the most thoroughly terrestrial, and the most active of the coal batrachians, if indeed they were not strictly intermediate between them and the lizards proper. [Fig. 138] shows some fragments of one of these animals; and the animal represented in [Fig. 139], recently figured by Fritsch, probably belongs to this group.
Fig. 138.—A lizard-like Amphibian (Hylonomus aciedentatus).
| a, Maxillary bone; enlarged. b, Mandible; enlarged. c, Teeth; magnified, showing front and side view of ordinary tooth and grooved anterior tooth. d, Section of tooth; magnified. | e, Scale; natural size and magnified. f, Pelvic bone (?); natural size. g, Rib; natural size. h, Scapular bone (?); natural size. i, Palate; natural size. |
Fig. 139.—Stelliosaurus longicostatus (Fritsch). Upper Coal-formation of Bohemia.
The Labyrinthodonts of the Carboniferous continue upward into the Permian, where they meet with the true reptiles; and in the earlier Mesozoic some of the largest and most typical examples are found.[61] But here their reign ceases, and they give place to reptiles of more elevated type, whose history we must consider in the next chapter.