Upper Oolite.
Some marsupial Mammals have left their remains in the Upper Oolite as in the Lower. They belong to the genus Sphalacotherium. Besides the Plesiosauri and Teleosauri, there still lived in the maritime regions a Crocodile, the Macrorhynchus; and the monstrous Pœcilopleuron, with sharp cutting teeth, one of the most formidable animals of this epoch; the Hylæosaurus, Cetiosaurus, Stenosaurus, and Streptospondylus, and among the Turtles, the Emys and Platemys. As in the Lower Oolite, so also in the Upper, Insects similar to those by which we are surrounded, pursued their flight in the meadows and hovered over the surface of the water. Of these, however, too little is known for us to give any very precise indication on the subject of their special organisation.
Fig. 122.—Bird of Solenhofen (Archæopteryx).
The most remarkable fact relating to this period is the appearance of the first bird. Hitherto the Mammals, and of these only imperfectly-organised species, namely, the Marsupials, have alone appeared. It is interesting to witness birds appearing immediately after. In the quarries of lithographic stone at Solenhofen, the remains of a bird, with feet and feathers, have been found, but without the head. These curious remains are represented in [Fig. 122], in the position in which they were discovered. The bird is usually designated the Bird of Solenhofen.
Fig. 123.
Shell of Physa fontinalis.