30 



Rhynchocephalia Hyperodapedon. 



Wall-case, 

 No. 8. 



This character was unknown until a few years ago, when a skull 

 in the collection, having the mandibles in natural position, was 

 skilfully developed from the matrix, and revealed the fact. 

 The biconcave form of the vertebrae, sternal and abdominal ribs, 

 and general characters of the limbs, also show the near affinity 

 of this ancient extinct land- lizard to its living representative. 



Pmx 



Hyperoda- 

 pedon. 



Wall-case, 

 No. 8. 



FIG. 37. Skull of Hyperodapedon Gordoni (Huxley), Triassic Sandstone, Lossiemouth, 

 Elgin, Morayshire, Scotland (j nat. size). A, upper surface of skull; B, palatal 

 aspect of skull; C, under side of front of lower jaw; Pmx, premaxillary bone; 

 MX, maxillary; PI, palatal teeth; Md, mandibles; 0, orbit. N, anterior nares : 

 S, supratemporal fossa ; 6", lateral temporal fossa. 



Another form, but of much larger proportions, named by 

 Prof. Huxley, Hyperodapedon, has been obtained from the 

 Triassic sandstone of Elgin, Morayshire, Scotland, having the 

 same compressed broadly triangular form of skull, with the 

 orbits directed upwards and the premaxillaries prolonged into a 

 sharp recurved beak, like Rhynchosaurus, which also may have 

 been encased in a horny sheath. 



The dentition is very peculiar, the maxillary and palatine 

 bones being provided with several rows of well-developed low 

 conical teeth closely set, and so arranged posteriorly as to form 

 a deep longitudinal groove between two or more rows of teeth 



