[D] Gallimimus bullatus [Su] [sG] [T]
Describer
Osmolska, Roniewicz & Barsbold, 1972
Time
Cretaceous Late Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Ornithomimosauria Ornithomimidae
Diet
Omnivore
Fossilsite
Nemegt Formation, Altan Uul, Bügiin Tsav, Nemegt; Tsagaan Khushuu, Mongolia
Length
6 meter
Info
Genus - Typespecies - Skull
2 nearly complete skeletons, complete postcranium, skull with associated fragmentary postcranium other fragmentary postcrania.
Gallimimus is a monotypic genus with Gallimimus bullatus as the type species. Three nearly complete skeletons from Mongolia\\\\\\\'s Gobi Desert make \\\\\\\"chicken mimic\\\\\\\" the best known ornithomimid, or ostrich dinosaur. Over twice the length of a modernday ostrich.
Gallimimus was the largest of a group of lightly built, bird-like theropods from Africa, East Asia, and western North America. It had a long, toothless beak, a slim neck, a short body, a stiffened tail, three- fingered hands, and slender legs. It also had a bird\\\\\\\'s intelligence and big, outward-facing eyes.
Compared to Struthiomimus, Gallimimus\\\\\\\'s small, light skull was longer, its hands were shorter, and its claws were more curved. The eyes were high above the ground and their fields of vision did not overlap. This would make it hard to judge distance well, but with one eye on each side of the head and a neck it could twist around.
Gallimimus would have been able to get an all- round view. Gallimimus bullatus was on average 3.5 m long, although one young specimen is 1.2 m long and the type specimen was almoust 8 m. This was the first ornithomimid to show parasphenoid capsule, a synapomorphy shared with troodontids and other ornithomimids.
Barsbold 1983
Holotype
GIN AN MNR no. 100/11; skull and incomplete postcranial skeleton.
Description
Skull with basisphenoid capsule open posteriorly, located anterior to the basipterygoid base and covering the interpterygoid cavity dorsally. As a result of this, the basisphenoid is additionally connected to the pterygoid by the ventral part of the capsule, which must have partially dislocated the basipterygoid articulation. Considerably reduced interpterygoid cavity. Incurrent opening of the parabasal canal located anterior to the basipterygoid processes. The bony base of the beak is elongated, and slightly broadened. The splenial does not reach the symphysis. Coronoid absent. 10 cervical, 13 dorsal, and 6 sacral vertebrae. Caudal vertebrae with elongated prezygapophyses. Precaudal vertebrae have pleurocoels. Clavicle and sternum absent. Scapulocoracoid with elongated scapula. [Ilium] with complete anterior and narrower posterior processes, the latter with parallel dorsal and ventral edges. Pubis elongated, with proximally displaced obturator process and hook-like, curved distal end. Humerus with weakened deltopectoral crest. Carpus of non-pulley type, metacarpals nearly subequal in size, and ungual phalanges slightly bent.
Comparisons
Ornithomimids represent a group generally fairly similar in construction, distinctions in which appear mainly in the proportions of skeletal elements. Thus, in Gallimimus the ratio of the length of the caudal to dorsal vertebrae (85%) is greater than in other genera (in Struthiomimus, for example, this ratio is approximately 76%). The sacrals in Gallimimus are also differentiated by their great elongation relative to the length of the femur. Besides these, in the Mongolian form the neural arches of the sacral vertebrae do not completely fuse even in mature specimens, in contrast to those observed in Ornithomimus and Struthiomimus. The ratio of the forearm to the arm reaches 66% in Gallimimus, while in the American forms listed it is 70% and even 91% (in Dromiceiomimus).
Discussion
The basisphenoid capsule is established only in Mongolian ornithomimids, but its presence has also been supposed in the American species, and not yet discovered purely because of the degree of preservation of the material.
Material
Besides the holotype, skulls and postcranial skeletons (nos. 100/10 and 100/12) and fragmentary remains of several specimens.
Source: Polyglot Paleontologist
Hurum (2001) described the lower jaw of a juvenile fragmentary skeleton (ZPAL MgD-1/1) recovered from the Upper Nemegt Beds during the Polish-Mongolian Palaeontological Expeditions. The paper thin, lower right jaw of this specimen revealed new details upon then not regognized. Hurum noticed that the jaw was toothless, slender and that its anterodorsal part was covered with a horney beak. Further he observed the following features: Splenial not extending to symphysis large ventral mylohyoid foramen; intramandibular joint indicating impossibility of separate movement of rostral part of lower jaw; preacetabular large, covering articular in medial view; preacetabular not covered by splenial anterodorsally, these bones having close fit; and absence of coronoid and supradentary.
Norell, Makovicky and Currie (2001) described a slightly crushed but almost complete skull (IGM 100/1133) belonging to a subadult Gallimimus bullatus, from Tsaagan Khushu in the Nemegt Formation, Nemegt Basin, Mongolia, this specimen demonstrates that ornithomimids possessed a presumably keratinous beak, furthermore this specimen displays lamellae similar to that found on extant ducs.
Currie in abstracts (2001, 2002) reports on two aprtial Gallimimus skeletons (PJC.2001.3 and PJC.2001.4) discovered on September 15, 2001 by Albert Miniaci in the Nemegt Formation, Central Sayr.
Osmolska, Roniewicz & Barsbold, 1972
Time
Cretaceous Late Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Ornithomimosauria Ornithomimidae
Diet
Omnivore
Fossilsite
Nemegt Formation, Altan Uul, Bügiin Tsav, Nemegt; Tsagaan Khushuu, Mongolia
Length
6 meter
Info
Genus - Typespecies - Skull
2 nearly complete skeletons, complete postcranium, skull with associated fragmentary postcranium other fragmentary postcrania.
Gallimimus is a monotypic genus with Gallimimus bullatus as the type species. Three nearly complete skeletons from Mongolia\\\\\\\'s Gobi Desert make \\\\\\\"chicken mimic\\\\\\\" the best known ornithomimid, or ostrich dinosaur. Over twice the length of a modernday ostrich.
Gallimimus was the largest of a group of lightly built, bird-like theropods from Africa, East Asia, and western North America. It had a long, toothless beak, a slim neck, a short body, a stiffened tail, three- fingered hands, and slender legs. It also had a bird\\\\\\\'s intelligence and big, outward-facing eyes.
Compared to Struthiomimus, Gallimimus\\\\\\\'s small, light skull was longer, its hands were shorter, and its claws were more curved. The eyes were high above the ground and their fields of vision did not overlap. This would make it hard to judge distance well, but with one eye on each side of the head and a neck it could twist around.
Gallimimus would have been able to get an all- round view. Gallimimus bullatus was on average 3.5 m long, although one young specimen is 1.2 m long and the type specimen was almoust 8 m. This was the first ornithomimid to show parasphenoid capsule, a synapomorphy shared with troodontids and other ornithomimids.
Barsbold 1983
Holotype
GIN AN MNR no. 100/11; skull and incomplete postcranial skeleton.
Description
Skull with basisphenoid capsule open posteriorly, located anterior to the basipterygoid base and covering the interpterygoid cavity dorsally. As a result of this, the basisphenoid is additionally connected to the pterygoid by the ventral part of the capsule, which must have partially dislocated the basipterygoid articulation. Considerably reduced interpterygoid cavity. Incurrent opening of the parabasal canal located anterior to the basipterygoid processes. The bony base of the beak is elongated, and slightly broadened. The splenial does not reach the symphysis. Coronoid absent. 10 cervical, 13 dorsal, and 6 sacral vertebrae. Caudal vertebrae with elongated prezygapophyses. Precaudal vertebrae have pleurocoels. Clavicle and sternum absent. Scapulocoracoid with elongated scapula. [Ilium] with complete anterior and narrower posterior processes, the latter with parallel dorsal and ventral edges. Pubis elongated, with proximally displaced obturator process and hook-like, curved distal end. Humerus with weakened deltopectoral crest. Carpus of non-pulley type, metacarpals nearly subequal in size, and ungual phalanges slightly bent.
Comparisons
Ornithomimids represent a group generally fairly similar in construction, distinctions in which appear mainly in the proportions of skeletal elements. Thus, in Gallimimus the ratio of the length of the caudal to dorsal vertebrae (85%) is greater than in other genera (in Struthiomimus, for example, this ratio is approximately 76%). The sacrals in Gallimimus are also differentiated by their great elongation relative to the length of the femur. Besides these, in the Mongolian form the neural arches of the sacral vertebrae do not completely fuse even in mature specimens, in contrast to those observed in Ornithomimus and Struthiomimus. The ratio of the forearm to the arm reaches 66% in Gallimimus, while in the American forms listed it is 70% and even 91% (in Dromiceiomimus).
Discussion
The basisphenoid capsule is established only in Mongolian ornithomimids, but its presence has also been supposed in the American species, and not yet discovered purely because of the degree of preservation of the material.
Material
Besides the holotype, skulls and postcranial skeletons (nos. 100/10 and 100/12) and fragmentary remains of several specimens.
Source: Polyglot Paleontologist
Hurum (2001) described the lower jaw of a juvenile fragmentary skeleton (ZPAL MgD-1/1) recovered from the Upper Nemegt Beds during the Polish-Mongolian Palaeontological Expeditions. The paper thin, lower right jaw of this specimen revealed new details upon then not regognized. Hurum noticed that the jaw was toothless, slender and that its anterodorsal part was covered with a horney beak. Further he observed the following features: Splenial not extending to symphysis large ventral mylohyoid foramen; intramandibular joint indicating impossibility of separate movement of rostral part of lower jaw; preacetabular large, covering articular in medial view; preacetabular not covered by splenial anterodorsally, these bones having close fit; and absence of coronoid and supradentary.
Norell, Makovicky and Currie (2001) described a slightly crushed but almost complete skull (IGM 100/1133) belonging to a subadult Gallimimus bullatus, from Tsaagan Khushu in the Nemegt Formation, Nemegt Basin, Mongolia, this specimen demonstrates that ornithomimids possessed a presumably keratinous beak, furthermore this specimen displays lamellae similar to that found on extant ducs.
Currie in abstracts (2001, 2002) reports on two aprtial Gallimimus skeletons (PJC.2001.3 and PJC.2001.4) discovered on September 15, 2001 by Albert Miniaci in the Nemegt Formation, Central Sayr.