12 GUIDE TO KEPTILES AND AMPHIBIANS. 



Order IV— RHYNCHOCEPHALIA— TUATERAS. 



(Case 5.) 



The New Zealand Tuatera (47) is the sole surviver of a Triassic 

 and Permian group, which is the most generalised of all Reptiles. In 

 the skull the quadrate-bone is fixed ; there are two temporal arches, 

 and teeth are present on the palate and the summits of the jaws, to 

 which they are welded. The vertebras have concave terminal faces, 

 and intercentra are developed in the trunk, and chevron -bones in 

 the tail. Each foot is five-toed ; the lower end of the humerus is 

 perforated on the inner side, and the abdomen is protected by a 

 aeries of small bones. 



The order is divided into : — 



I. Rhynchocephalia Veea, in which the abdominal bones are 

 closely packed, with three elements in each transverse series, 

 and there are two sacral vertebras, the intercentra being 

 sometimes suppressed. 



II. Protorosauria, in which each series of abdominal bones 

 consists of a number of elements, and the intercentra are 

 fully developed. This group passes into the Microsauria, 

 among the Stegocephalan Amphibia, in which the body is 

 armoured, the vertebras are completely ossified, and the ribs 

 retain two heads. 



Case 5. The Tuatera itself (Sphenodon punctatus, 47, fig- 11) is a 



burrowing lizard-like reptile, now confined to a few small islands 

 off the New Zealand coast, having been exterminated from the 

 mainland by pigs. These Reptiles share their burrows with birds — 

 shear-waters, or petrels. They feed entirely upon small living 

 animals, and deposit their eggs in a chamber, forming one side 

 of the extremity of the burrow, the shear-water occupying the 

 opposite side. 



Casts of skulls of the extinct Rhymhosaurus (50) from the Trias 

 of Shropshire, and of Hyperodapedon (49) from the same forma- 

 tion in both England and India, are exhibited in the case. Both 

 were near allies of the Tuatera, but in Hyperodapedon the teeth 

 formed a kind of pavement on the palate. Casts of the skeletons 

 of Sapheosaurus (46), from the Oolite of Bavaria, an allied type, 

 and of Protorosaurus lincTci (48) are shown. 



