[D] Acrocanthosaurus atokensis [Su] [sG] [T]
Describer
Stovall & Langston, 1950
Time
Cretaceous Early Aptian Albian
Classification
Saurischia Theropoda Tetanurae Carnosauria Carcharodontosauridae
Diet
Carnivore
Fossilsite
Antlers Formation, Oklahoma, Antlers Formation, Paluxy River Formation, Twin Mountains Formation, Texas, Middle Cedar Mountain Formation, Utah, US
Length
12 meter
Info
Genus - Typespecies - Skull - Sail
Two parical skulls with associated postcrania. Spinosaurids (\\\\\\\"spine reptiles\\\\\\\") are the group of relatively tall-spined theropods. They include such forms as Altispinax and Metriacanthosaurus. The family was founded on the remains of Spinosaurus which come from the Late Cretaceous of Niger (Africa) and Egypt. The original material is agian somewhat incomplete, including parts of the jaw, and some neck, back and tail vertebrae, but it indicates a large theropod 33-39.4ft (10-12m) long with spines up to 6ft (1.8m) long!
Molnar (2001) reffered Acrocanthosaurus and Carcharodontosaurus to a new family [Acrodontosauridae]. Coria and Currie (2003) questioned the assignment of Acrocanthosaurus to the Carcharodontosauridae because the braincase of Acrocanthosaurus \\\\\\\"lacks all of the carcharododontid braincase synapomorphies revealed in their study and strongly suggested that Acrocanthosaurus is not related to the Gondwanian family, however Fanzoza (2002) reported on a CATscan of the braincase of the holotype OMNH 8-0-59 and concluded that the endocast of Acrocanthosaurus is similar to those of the closely related genera Allosaurus and Carcharodontosaurus.
(MOU 8-0-S8 or OMNH 10147) (11.7 m; 2.5 tons) two dorsal centra, four dorsal neural spines, eight posterior dorsal ribs, first caudal vertebra, second caudal vertebra (128 mm), third caudal vertebra (138 mm), fourth caudal vertebra (140 mm), ninth caudal vertebra (149 mm), tenth caudal vertebra (146 mm), eleventh caudal vertebra (141 mm), twelfth caudal vertebra (140 mm), eighteenth caudal vertebra, nineteenth caudal vertebra (131 mm), twentieth caudal vertebra (134 mm), twenty-first caudal vertebra (135 mm), twenty-second caudal vertebra, twenty-third caudal vertebra (124 mm), proximal chevron, pubes, proximal femur (~950 mm), fragmentary tibia (~958 mm), metatarsal II (416 mm), metatarsal III (445 mm), phalanx III-1 (145 mm) (Stovall and Langston 1950) (NCSM 14345) (11.5 m; 2.4 tons) skull (1.23 m), mandible (1.315 m), cervical rib, several dorsal ribs, gastralia, fourteen caudal vertebrae, six chevrons, about ten partial vertebrae, scapulocoracoid (1.18 m), humerus (370 mm), radius (220 mm), ulna (255 mm), ulnare, radiale, distal carpal 1+2, metacarpal I (62 mm), phalanx I-1 (111 mm), metacarpal II (116 mm), phalanx II-1 (101 mm), phalanx II-2 (103 mm), manual ungual II, metacarpal III (89 mm), phalanx III-1 (50 mm), phalanx III-2 (42 mm), phalanx III-3 (60 mm), manual ungual III, partial femur (~1.28 m), incomplete tibia (960 mm), partial astragalus, calcaneum, metatarsal I (111 mm), phalanx I-1 (70 mm), pedal ungual I, metatarsal II (410 mm), phalanx II-1 (55 mm), phalanx II-2 (122 mm), proximal metatarsal III (~440 mm), phalanx III-1 (160 mm), phalanx III-2 (115 mm), proximal metatarsal IV, phalanx IV-1 (85 mm), phalanx IV-2 (70 mm), phalanx IV-3 (58 mm), metatarsal V (200 mm) (OMNH 10168) vertebral fragments, ischium, femur Both the paratype and new incomplete skeleton are comparable in size. [M.Mortimer]