Suborder Protosuchia

Although their skulls were slightly more crocodilelike in appearance, the proto-suchians were still long-legged land-dwellers like the sphenosuchians (above). They lived all over the world during the early part of the Jurassic period. Some members may have developed a secondary palate that separated the mouth from the nasal passages, but it could only have been made of a fleshy membrane as yet, since there is no sign of the solid bony palate developed in later crocodiles.

name: Protosuchus time: Early Jurassic locality: North America (Arizona) size: 3 ft 3 in/1 m long

Protosuchus was obviously a terrestrial crocodile, since it has been found in rocks that also yielded the remains of dinosaurs. It would have shared its North American homeland with such carnivorous dinosaurs as the agile, 2-Iegged coelurosaurs (see pp. 106-109) and the newly evolved carnosaurs (see pp. 114-117).

The skull of Protosuchus was more crocodilelike in appearance than that of the earlier sphenosuchians. The short jaws broadened out at the base of the snout into a fairly wide area at the back of the skull. This provided a large surface to which the jaw muscles could attach, thereby increasing the gape of the jaws and the force with which they could be closed.

Among the sharp teeth, there was a pair of long caninelike teeth at the front of the lower jaw, which fitted into a notch on either side of the upper jaw

when the mouth was closed.

This tooth arrangement is characteristic of modern crocodiles. Alligators also have lower canines, but they fit into bony pits in the upper jaw.

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