PARASUCHIA 



189 



related most nearly 

 to the crocodiles and 

 dinosaurs, and are 

 probably an early 

 branch of the stem 

 from which they, the 

 pterodactyls and the 

 birds, arose, a branch 

 that persisted only a 

 short time, geologi- 

 cally speaking, and 

 went entirely out of 

 existence at the close 

 of Triassic times, 

 leaving no descend- 

 ants behind. Never- 

 theless, in this 

 comparatively brief 

 life-span they devel- 

 oped not a few dis- 

 tinctive forms and 

 became widely dis- 

 tributed over the 

 earth. Their remains 

 are known from the 

 Upper Trias of Ger- 

 many, England, and 

 Scotland, India, 

 South Africa, and 

 from Massachusetts, 

 North and South 

 Carolina, and many 

 places in the Rocky 

 Mountains. No true 

 phytosaurs are yet 

 known from South 

 America, but in all 



Fig. 93. — Skull of Mystriosiichus, a phytosaur: pm, 

 premaxilla; m, maxilla; na, nasal; /, frontal; p, pre- 

 frontal; /, lacrimal; pf, postfrontal; po, postorbital; 

 pa, parietal; sg, squamosal; qj, quadratojugal; 

 pi, palatine; /, transverse; in, internal nares; en, 

 external nares; pt, pterygoid; bs, basisphenoid; eo, 

 exoccipital. (After McGregor.) 



