Volume 1

A picture book of evolution / by Dennis Hird.

  • Dennis Hird
Date:
1906-1907
Catalogue details

Licence: Public Domain Mark

Credit: A picture book of evolution / by Dennis Hird. Source: Wellcome Collection.

    144/220 page 132
    We must always bear in mind that the vast majority of reptiles are extinct. The first three great sub-classes are :— I. Proreptilia. II. Prosauria (containing orders, microsauri and prosauri). III. Theromorpha(containingorders,pareiasauri, theriodontia, anomodontia, placodontia). The remaining sub-classes do not concern our present inquiry, but the first three sub-classes, with their early low forms, are of the greatest interest to us in looking for the origin of mammals. The sub-class I., proreptilia, contains two genera, eryops and cricotus, both found in the Permian formation of rocks in North America. They are called proreptilia, which really means before reptiles proper, to show that they are the lowest known reptiles, and that they probably link this class to the amphibia. In fact, for a time they were mistaken for amphibia, and classed with the roof-headed. In some points they resemble the roof-headed amphibians, and they are found side by side with them in the lower Permian rocks. The sub-class II., the prosauria, which means before lizards proper, includes small newt-shaped, chiefly Permian, reptiles. These little creatures had five fingers and toes, but they stand almost as low as the first sub-class, and in many points resemble amphibians. The most amazing thing about this sub-class is that there still exists a living specimen, the sole surviving member of this very early group. There is only one species of him (sphenodon punctatus), and that is found in New Zealand, living there in the pride of antiquity. Try and realise what the ancestors of this beautiful creature
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