LIFE OF THE PERMIAN. The close of the Paleozoic was, as we have
seen, a time of marked physical changes. The upridging of the
Appalachians had begun and a wide continental uplift--proved by
the absence of Permian deposits over large areas where
sedimentation had gone on before--opened new lands for settlement
to hordes of air-breathing animals. Changes of climate compelled
extensive migrations, and the fauna of different regions were thus
brought into conflict. The Permian was a time of pronounced
changes in plant and animal life, and a transitional period
between two great eras. The somber forests of the earlier
Carboniferous, with their gigantic club mosses, were now replaced
by forests of cycads, tree ferns, and conifers. Even in the lower
Permian the Lepidodendron and Sigillaria were very rare, and
before the end of the epoch they and the Calamites also had become
extinct. Gradually the antique types of the Paleozoic fauna died
out, and in the Permian rocks are found the last survivors of the
cystoid, the trilobite, and the eurypterid, and of many long-lived
families of brachiopods, mollusks, and other invertebrates. The
venerable Orthoceras and the Goniatite linger on through the epoch
and into the first period of the succeeding era. Forerunners of
the great ammonite family of cephalopod mollusks now appear. The
antique forms of the earlier Carboniferous amphibians continue,
but with many new genera and a marked increase in size.

A long forward step had now been taken in the evolution of the
vertebrates. A new and higher type, the reptiles, had appeared,
and in such numbers and variety are they found in the Permian
strata that their advent may well have occurred in a still earlier
epoch. It will be most convenient to describe the Permian reptiles