OSTEOLOGY OF CARNIVOROUS DINOSAURS. 



9 



In 1903 Osborn x described and figured cranial material, identified as pertain- 

 ing to the genus Creosaurus, but subsequently 2 referred by him to Allosaurus. 

 (See fig. 3.) There are two skulls in the American Museum of Natural History, 

 New York, from the famous "Bone Cabin Quarry," in Wyoming, both of which are 

 considerably larger that the specimen now before me, as is shown by the table of 

 comparative measurements given below. 



©v6. ritg. 



No.5027 

 AM. 



Fig. 2 — Skull and lower jaw of Tyrannosaurus rex Osborn. No. 5027, A.M.N. H. £nat. size, ang, angular; ant.f; ant. 

 J"; ant.},'" antiorbital fenestrae; ant.nar, anterior nares; art, articular; den, dentary; ;'./, jugal foramen; ju, jugal ; 

 la, lachrymal; lat.temp.fen, lateral temporal fenestra; mx, maxillary; na, nasal; orb, orbit; orb.rug, orbital rugo- 

 sity; op.o, paraoccipital; pa, parietal; p.o, postorbital+postfrontal; pr.mx, premaxillary; qu, quadrate; qu.j, 

 quadratojugal; sq, squamosal; sur, surangular; * foramen. (After Osborn.) 



Comparative measurements of Antrodemus crania. 



Length, occipital condyle to end of premaxillary 



Depth, parietal crest to distal extremity of quadrate. 



Width of occiput across parietals 



Vertical measurement of quadrate 



U.S.N.M. 

 No. 4734. 



mm. 

 605 

 355 

 153 

 190 



A.M.N.H. 

 No. 600. 



mm. 

 810 

 415 



205 



A.M.N.H. 

 No. 666. 



885 

 430 

 230 

 235 



i Osborn, H. F. The Skull of Creosaurus, Bull. Amer. Mus. Nat. Hist., vol. 19, 1903, pp. 697-701, figs. 1 and 2. 



2 Crania of Tyrannosaurus and Allosaurus, Memoirs Amer. Mus. of Nat. Hist., vol. 1, newser.pt. 1, 1912, pp. 27, 29, figs. 26, 27. 



