Tyrannosaurus rex Osborn, 1905

John S. McIntosh, 1981, Annotated catalogue of the dinosaurs (Reptilia, Archosauria) in the collections of Carnegie Museum of Natural History, Bulletin of Carnegie Museum of Natural History 18, pp. 1-67 : 8-9

Family Tyrannosauridae

Genus Tyrannosaurus Osborn, 1905

Tyrannosaurus rex Osborn, 1905

9380 Skeleton consisting of partial skull and mandible, one cervical, seven dorsals, five sacrals, three abdominal ribs, right scapula, left humerus, ilia, pubes, ischia, left femur and part of right, tibia, right metatarsals II and III, left metatarsal IV. Type specimen. It was collected in the Lance Formation at Hell Creek , Garfield County, Montana, and was described and figured by Osborn—Bull. Amer. Mus. Nat. Hist. (1905), 21:262-263, Fig. 1 ; Bull. Amer. Mus. Nat. Hist. (1906), 22:281-296, Figs. 1-12 ; Bull. Amer. Mus. Nat. Hist. (1917), 35:762-771, Figs. 19-21 ; Mem. Amer. Mus. Nat. Hist., n.s. (1912), l: Figs. 20-24 . This skeleton (formerly AMNH 973), obtained from the American Museum of Natural History, is mounted and was placed on exhibition in 1942.

Collected by B. Brown, 1902-1903

9379 Brain cast of AMNH 5029 collected in the Lance Formation (Hell Creek beds) on the west side of Big Dry Creek, 44 mi south of Glasgow , Garfield County, Montana. This cast was also obtained from the American Museum of Natural History and was figured by Osborn—Mem. Amer. Mus. Nat. Hist., n.s. (1912), 1:13-24, Pls. 3-4 and Figs. 16­ 17 .

Original collected by Brown and Kaisen, 1908

1400 Part of the skull including the maxilla, cranium and both lower jaws, two dorsals, seven caudals, ribs, chevrons, part of pubis, ilium, femur, and other bones. It was obtained from the Lance Formation on Snyder Creek, Niobrara County, Wyoming. The upper jaw is on exhibition.

Collected by Peterson, 1902

244 A phalanx from the Lance Formation on Lance Creek , Niobrara County, Wyoming.

Collected by Hatcher, 1900

Figures

Fig. 1. Rough outline showing scale of size of Tyrannosaurus rex. By W. D. M. The association of the small forearm is probably incorrect.

Fig. 1. Skull of Tryrannosaurus. d, dentary; sur, surangular; sq, squamosal; prf, prefrontal; o, orbit; na, anterior nares; 1, 2, 3, antorbital openings. Dotted outlines are from Allosaurus.

Fig. 2. Skull of Allosaurus in the American Museum of Natural History. To same scale as the skull of Tyrannosaurus.

Fig. 3. Cervical vertebrm of Tyrannosaurus.,Amer. Mus. No. 5866. hypocentrum of atlas; nph, neuropophysis; 2 supposed axis with its hypocentium; od, odontoid; 3, 9 remaining cervicals; r8, r9, ribs found attached to ribs, 8-9, 10-11, cervico-dorsals; c, capitular facet; t, tubercular facets.

Fig. 4. Anterior view of mid-cervical vertebra, Amer. Mus No. 5866.

Fig 5. Sacrum of Tyrannosaurus. Amer. Mus. No. 973. 1-5, sacrals 1-5.

Fig. 6. B Scapula of Tyrannosaurus. A Scapula of Allosaurus.

Fig. 7. Pelvis of Tyrannosaurus. Amer. Mus. No. 73.

Fig. 8. Humerus of Tyrannosaurus. Amer. Mus. No. 972. To same scale as femur (Fig. 9). a, external view; b, posterior view.

Fig. 9. Femur of Tyrannosaiurus. Amer. Mus. No. 973. a, posterior view; b, internal view.

Fig. 10. Section of femur of Tyrannosaurus. Amer. Mus. No. 973.

Fig. 11. Right pes of Tyrannosaurus. Amer. Mus. No. 973.

Fig. 12. Abdominal ribs of Tyrannosaurus. Amer. Mus. Nos. 973 and 5881.

Fig. 19. Sacro-pelvic arcade of Tyrannosaurus rex of the genotype specimen Amer. Mus. 973, discovered in Hell Creek, Montana, in 1904. A, Sacral aspect of the right ilium showing the respective attachments of the five sacrals S 1-5. B, Left lateral aspect of the sacrum, exhibiting centra of S 1-5, also the sacral rib attachments S 1-5 to the inner aspect of the left ilium. C, Anterior aspect of the sacro-iliac arcade, SI, the first sacral vertebra. D, Posterior aspect of the sacro-iliac arcade showing S5, the fifth sacral. All figures one fifteenth natural size.

Fig. 20. Comparative views of the sacro-iliac arcade in Tyrannosaurus rex. To the right, superior and inferior views of the type specimen Amer. Mus. 973. To the left, inferior view of the second specimen, Amer. Mus. 5027, including dorsals, D12, 13, also the first caudal, Cl. S2, S2-5 are strongly crushed laterally, deforming their proportions.

Fig. 21. Humerus and femur of Tyrannosaurus rex, type specimen Amer. Mus. 973. One-fifteenth natural size. B Humerus in three aspects, (1) posterior, (2) exterior, (3) anterior. A1 right femur, internal aspect, A2 the same, anterior aspect, A3 the same, posterior aspect. One-fifteenth natural size.

Fig. 20. Tyrannosaurus rex. Amer. Mus. No. 973. Inner view of left dentary, with the splenial and supradentary absent. The small rugose plates between the teeth are outgrowths of the dentary alveolar borders. Below them is a groove for the bloofl vessel supplying the roots of the teeth (see Fig. 13).

Fig. 21. Tyrannosaurus rex. Inner view of dentary between exposed alveoli of 7th to 10th teeth. Amer. Mus. No. 973. Rela­ tions of the nutrient groove (gr.) and foramina (f) to the interdental plates (rugosae) and teeth.

Fig. 22. Tyrannosaurus rex. Left maxilla, outer view. Amer. Mus. No. 973. (Type.) Scale 1/6.

Fig. 23. Tyrannosaurus rex. Left maxilla, inner view of the same specimen, Amer. Mus. No. 973. Exhibiting eight of the maxillary teeth, four vacant alveoli, and nine interdental plates of the maxilla.

Fig. 24. Tyrannosaurus rex. Cross section through the dentary showing a small successional tooth on the inner side of a functional tooth. Amer. Mus. No. 973. Scale 1/2.

Plate III. Tyrannosaurus rex. Section of skull showing brain cavity. Amer. Mus. No. 5029: Scale 1/2.

Plate IV. Tyrannosaurus rex. Section of skull showing cast of brain in situ. Amer. Mus. No. 5029. Scale 1/2.

Fig. 16. Diplodocus longus Marsh. Amer. Mus. No. 694. Scale 1/2. A, sagittal section with “ brain cast” in place. B, “ “ “ “ “ removed. S. end., saccus endolymphaticus. ves., region of vestibulum (recessus vestibuli).

Fig. 17. Tyrannosaurus rex. Superior aspect of brain cast, from skull no. 5029 Amer. Mus. (cf. Pl. III). Scale å. h‘, hi., membranous prolongations of dura mater. *, marks the position of the saccus vasculosus. †, marks the position of the ethmoid septum. Olf., olfactory peduncles. Op. l., optic lobes. V‘, Ramus ophthalmicus trigemini. V’, 3, Rami maxillaris et mandi- bularis trigemini.