[D] Gigantspinosaurus sichuanensis [sG] [T]
Describer
Ouyang, 1992
Time
Jurassic Late
Classification
Ornithischia Thyreophora Stegosauria
Diet
Herbivore
Fossilsite
Shangshaximiao Formation of Pengtang, Jinquan, Zigong, Sichuan Province, China
Info
Genus
Holotype
ZDM unnumbered, comprising a lower jaw with teeth, three cervical, 16 dorsal and four sacral vertebrae, scapulocoracoids, a humerus, ulna, radius, carpals and metacarpals, ilia, ischium, pubis, tibia, fibula, astragalus, four dermal plates and two large parascapular spines (Ouyang, 1992).
Current location of material
A skeletal mount of Gigantspinosaurus sichuanensis that incorporates much of the original material, including dorsal vertebrae, a left scapulocoracoid, both femora, a right tibia and fibula, four dermal plates and a right parascapular spine, has been on public display in the Zigong Dinosaur Museum since 1996 (Li, He & Cai , 1996). The left parascapular spine and a cast of the lower jaw are also on display but are not in the mount.
Diagnosis
Differs from all other stegosaurs in possessing parascapular spines that are at least twice the length of the scapulae. New descriptive data. Gigantspinosaurus sichuanensis has only briefly been described in a short note (Ouyang, 1992), and is currently under study by the Zigong Dinosaur Museum staff.
Original species description
Although Gigantspinosaurus sichuanensis has never been formally diagnosed, it has been described briefly, and the pertinent points from that description are given here:
(1) lower jaw with external mandibular fenestra;
(2) well-developed coronoid process;
(3) more than 30 teeth in the lower jaw;
(4) teeth with prominent cingula;
(5) dorsal vertebrae have low neural arches and small neural canals;
(6) transverse processes of dorsal vertebrae are not elevated relative to the horizontal;
(7) fused scapula and coracoid;
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end of scapula not expanded relative to the shaft;
(9) poorly developed acromial process of scapula;
(10) coracoid approximately the same size as proximal scapula;
(11) ulna is 80% length of humerus;
(12) radius is 70% length of humerus;
(13) manus phalangeal formula – 2-3-3-2-1;
(14) sacrum perforated by small fenestrae in dorsal view;
(15) ilium longer than femur;
(16) prepubis about half the length of the postpubis;
(17) distal ends of ischium and pubis not expanded;
(18) femur to humerus ratio = 1.48;
(19) astragalus is unfused to tibia and fibula;
(20) parascapular spines are double the length of the scapula.
Gigantspinosaurus (although the parascapular spine of Lexovisaurus is not complete, it is less robust than that of Gigantspinosaurus and probably was not as long). The presence of parascapular spines twice the length of the scapula is therefore a unique derived character and can be used to diagnose the genus.
Ouyang, 1992
Time
Jurassic Late
Classification
Ornithischia Thyreophora Stegosauria
Diet
Herbivore
Fossilsite
Shangshaximiao Formation of Pengtang, Jinquan, Zigong, Sichuan Province, China
Info
Genus
Holotype
ZDM unnumbered, comprising a lower jaw with teeth, three cervical, 16 dorsal and four sacral vertebrae, scapulocoracoids, a humerus, ulna, radius, carpals and metacarpals, ilia, ischium, pubis, tibia, fibula, astragalus, four dermal plates and two large parascapular spines (Ouyang, 1992).
Current location of material
A skeletal mount of Gigantspinosaurus sichuanensis that incorporates much of the original material, including dorsal vertebrae, a left scapulocoracoid, both femora, a right tibia and fibula, four dermal plates and a right parascapular spine, has been on public display in the Zigong Dinosaur Museum since 1996 (Li, He & Cai , 1996). The left parascapular spine and a cast of the lower jaw are also on display but are not in the mount.
Diagnosis
Differs from all other stegosaurs in possessing parascapular spines that are at least twice the length of the scapulae. New descriptive data. Gigantspinosaurus sichuanensis has only briefly been described in a short note (Ouyang, 1992), and is currently under study by the Zigong Dinosaur Museum staff.
Original species description
Although Gigantspinosaurus sichuanensis has never been formally diagnosed, it has been described briefly, and the pertinent points from that description are given here:
(1) lower jaw with external mandibular fenestra;
(2) well-developed coronoid process;
(3) more than 30 teeth in the lower jaw;
(4) teeth with prominent cingula;
(5) dorsal vertebrae have low neural arches and small neural canals;
(6) transverse processes of dorsal vertebrae are not elevated relative to the horizontal;
(7) fused scapula and coracoid;
(
end of scapula not expanded relative to the shaft;(9) poorly developed acromial process of scapula;
(10) coracoid approximately the same size as proximal scapula;
(11) ulna is 80% length of humerus;
(12) radius is 70% length of humerus;
(13) manus phalangeal formula – 2-3-3-2-1;
(14) sacrum perforated by small fenestrae in dorsal view;
(15) ilium longer than femur;
(16) prepubis about half the length of the postpubis;
(17) distal ends of ischium and pubis not expanded;
(18) femur to humerus ratio = 1.48;
(19) astragalus is unfused to tibia and fibula;
(20) parascapular spines are double the length of the scapula.
Gigantspinosaurus (although the parascapular spine of Lexovisaurus is not complete, it is less robust than that of Gigantspinosaurus and probably was not as long). The presence of parascapular spines twice the length of the scapula is therefore a unique derived character and can be used to diagnose the genus.