512 



ZOOLOGY. 



The Ichtliyosaurs were colossal reptiles from two to thirteen 

 metres (six to forty feet) in length, swimming in the ocean by 

 four paddle-like limbs consisting of six rows of digital bones ; 



Fig. 448. Skull of Ichthyosaurus ; lateral view. Pmx, premaxillary bone ; MX, 

 maxillary; JV, nasal; Fr, frontal; Prf, prefrontal; Pof, postfrontal ; Pa, parietal; 

 i, lachrymal; M, malar; Qj, quadratojugal ; Q, quadrate; Fob, postorbital ; Sq, 

 equamosal ; D. dentary ; Any, angular ; Art, articular ; S. Ar, subarticular ; Pter, 

 pterygoid. After Cope. 



the head was very large, the neck very short, and the orbits 

 were enormous ; the vertebras were remarkably short and bi- 

 concave. They were carniv- 

 orous, and powerful swim- 

 mers, and common in the Ju- 

 rassic seas of Europe ; one 

 form existed in the Jurassic 

 times in Wyoming. 



Order 7. Theromorpha. 

 This order is divided into the 

 Pelycosauria and Anovio- 

 dontia. The beaked Saurians 

 were somewhat lizard-like, but 

 Fig. 449.-po?tprior view of the skuii of were synthetic types, combin- 



Ichtrlyo*auru8 ; lettering as in Fig. 443, . 



with following additions; Bo, basiocci- lllg the Characters OI the Icil- 



pital ; &KO, Exoccipita! ; Sup. 0, supra- , , ^ ,, ., ,, 



occipital ; Opo, opisthotic ; Star*, supra- thyOSaurs, the turtles, tlie 



stapedial or hyoruandibular. After Cope. a 7 7 .,-, ,-, v 



isphenoaon, with those 01 liz- 

 ards, Dinosaurians, and crocodiles. The skull was short, 

 and in Dicynodon the jaws in front had the nipping, horny 

 beak of a turtle, while from behind in the upper jaw pro- 

 truded two long, curved, canine teeth. Dicynodon tiyriceps 

 Owen, had a skull about half a metre (20 inches) long. 



