[D] Garudimimus brevipes [Su] [sG] [T]
Describer
Barsbold, 1981
Time
Cretaceous Late Cenomanian Turonian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Ornithomimosauria Garudimimidae
Diet
?
Fossilsite
Baynshirenskaya Svita, Baishin Tsav, Omnogov, Mongolia
Info
Genus - Typespecies - Skull
Skull with associated incomplete poscranium. The family Garudimimidae includes but one species, Garudimimus brevipes. G.brevipes has a skull that does not differ in its basic structure from that in ornithomimid species, but the infratemporal fenestra is reduced and the quadrate is more vertical. This species is also very primitive in many other respects among ornithomimmosaurians. The manus is unknown. Retained its first pedal digit.
Etymology
After the bird Garudi in the mythology of eastern peoples. | From brevis, Latin “short”; pes, Latin “foot”.
Species type
Garudimimus brevipes Barsbold, gen. et sp. nov.
Genus composition
Monotypic species
Distribution
Early Senonian, South Eastern Mongolia.
Holotype
#100/13, GIN AN MNR; skull; fragments of axial skeleton, pelvis and incomplete posterior limbs; lower Senonian, Bayanshipensk suite, Bayshin- Tsav location, South Eastern Mongolia.
Material
Holotype Description
Ventral part of the base of the open basisphenoidal capsule in front of the basipterygoidal processes (to which it passed without interruption) connected with the medial edges of the pterygoids, 7 dorsally, but covering the interpterygoidal cavity. Such additional articulation of the capsule with thepterygoids must have blocked the basipterygoidal articulation, denying it mobility. Interpterygoidal cavity is considerably reduced. Entering openings of the parabasal canals are located immediately in front of the horizontally directed and shortened basipterygoidal processes. Anteriorly and laterally from the openings, adjoin the pterygoids, lining their areas next to the edge. The epipterygoids in the shape of V-shaped lamella, are ventrally wider. In the lower jaw the lamella ends in a V-shape, without reaching the symphysis. The coronary is absent. The retroarticular process is widened, with dorsally open large recess, which attached m. depressor mandibulae. The medial edge of the process was highly thickened and, apparently, rested against the base of the quadrate, interfering, as in the case of the dromesaurid (Colbert and Russell, 1969) to the extreme displacement of the lower jaw. The dorsal and sacral (caudal are not in the collection) vertebrae have no pleurocoels.
There are six sacral vertebrae. The distal end of the left rib is separated from the diapophysis and leans against the medial surface of the ilium. The ilium is high, a little shorter than the pubis, with narrowed posterior wing, the upper and lower edge of which are sub-parallel. The femur is insignificantly shorter than the tibia. III tarsal element lay on the proximal articular surfaces of predominantly the III and only partially the II metatarsal bones. IV tarsal element fully articulated with same named metatarsal bone. In the foot three basic (II, III, IV) and two residual (I, V) metatarsals. I metatarsal has a reduced, distally V-shaped trunk, adjacent to the II metatarsal. Distal metatarsal is the shortest and thickest, its proximal end is 8 anteriorly widened, posteriorly slightly compressed.
The III is the most thickened and elongated, in the distal part slightly curved, in the proximal part slightly compressed. IV metatarsal in length occupied intermediary position between II and III, its proximal end is widened. Distal head of the bones with convex articular surfaces, are slightly divided sagitally by a furrow. V metatarsal is highly reduced to a narrow, laterally compressed residual element, attached to the IV metatarsal. The first toe is the most reduced, its ungula is noticeably compressed from the sides. Phalanges of each of the remaining toes decreased progressively in the distal direction, which is best expressed in the fourth toe, the ungula of which has a flattened ventral surface (in the second and third toes the unguals are not known).
Observations
According to the development of the basisphenoidal capsule, which is open posteriorly, the skull of Gallimimus is in many aspects similar to that of Gallimimus. It was possible to establish that in the latter that the so-called basipterygoidal branches of the pterygoids (Osmolska et al., 1972) in reality are the epipterygoids. The same type of skull structure in Garudimimus and Gallimimus allow the generalization of the development of the basisphenoidal capsule and the blocked basipterygoidal articulation for the whole group (there is a possibility of the presence of the capsule in one of the American species, see Parks, 1933; Osmolska et al., 1972). Parabasal canals have similar structures, and most likely were a distinguishing characteristic for the whole group. The capsule (closed type), the supposed blocked basipterygoidal articulation and the horizontal orientation of the basipterygoidal processes in the saurornithoidids (Barsbold, 1974) create an expectation of the development of 9 the parabasal canals also in this family of theropods. The shortness of the ilium and the metatarsus, the lack of compression of the III metatarsal and the development of the first toe differentiate Garudimimus from all representatives of the progressive branch of the ornithomimosaurs.
Geologic age
Lower Senonian, Bayasirensk suite. Location: South Eastern Mongolia, location Bay-shin-tsav.
Holotype Barsbold 1983
PST GIN AN MNR no. 100/13; skull, fragments of the axial skeleton, pelvis and incomplete limbs.
Description
Basisphenoid capsule open posteriorly, connected with the medial edges of the pterygoid, covering the reduced interpterygoid cavity dorsally. Basipterygoid articulation supposedly immobile. Incurrent opening of the parabasal canal limited laterally by the ventral edge of the quadrate flange of the pterygoid, posteriorly by the pterygoid process, and medially and ventrally by the basisphenoid capsule.
The canal is shortened and directed initially ventrally, then enters into the space between the quadrate flange of the pterygoid and the base of the basisphenoid capsule. From here, there is possibly a passage lining the pterygoid capsule more dorsally, between the front posterior edge of the quadrate flange and the ventrolateral part of the capsule. The ectopterygoid has the appearance of a ventrally widened, V-shaped lamina. In the lower jaw, the splenial has a V-shaped end and does not reach the symphysis.
The coronoid is absent. The retroarticular process is widened, with an indentation open dorsally. Dorsal and sacral vertebrae lack pleurocoels. Six sacral vertebrae. In the first sacral, the rib is separated from the diapophysis and contacts the medial surface of the [ilium] with its distal end. The [ilium] is high anteriorly, has a dorsal edge with a rounded, convex shape, and is slightly shorter than the pubis.
The posterior process of the ilium is narrowed, with parallel dorsal and ventral edges. Femur slightly shorter than the tibia. Two tarsals (3 and 4), of which 3 rested mostly on the proximal articular surface of metatarsal III and only partly on that of II. Tarsal 4 fully connected with metatarsal IV. Five compositional elements in the pes: three basic (II, III, IV) and two residual (I, V) metatarsals.
Metatarsal I with reduced, distally V-shaped shaft, laterally adjoining metatarsal II. The distal head has a convex articular surface, directed ventromedially. Of the three basic elements, metatarsal II is more shortened, its proximal end is widened anteriorly, and it is narrowed posteriorly. Metatarsal III is the most elongated and thickened, slightly curved distally, almost not highly compressed proximally, and fully divides the adjoining metatarsals. Metatarsal IV is intermediate in length between II and III, with a broad proximal end.
The distal end of the bone has convex articular surfaces divided weakly by a furrow. Metatarsal V is highly reduced to the condition of a narrow, laterally compressed rudiment, attached to the side of metatarsal IV. Pedal digit I is the most reduced, with its ungual phalanx notably laterally compressed. The phalanges of each digit are progressively smaller distally, a trend most clearly expressed in digit IV. Its ungual phalanx (the ungual phalanges are not known for the other digits) has a flattened ventral surface.
Discussion
The skull of Garudimimus is similar in many ways to that of Gallimimus , especially in the development and construction of the basisphenoid capsule, open posteriorly. In the latter, the epipterygoids were successfully defined as so-called basipterygoid rami of the pterygoid (Osmólska, Roniewicz, and Barsbold, 1972).
The parabasals are similarly constructed in representatives of both families. The shortening of the ischium and metatarsus, the lack of compression of metatarsal III and its complete separation of II and IV (which do not contact each other), and the connection of tarsal 3 mostly with the proximal articular surface of metatarsal III serve as basic differentiating signs of garudimimid features.
The laterally closed basisphenoid capsule, supposedly blocked by the pterygoid articulation, and a similar type of parabasal canal are characteristic of saurornithoidids, in addition to Garudimimus and Gallimimus . The construction of the pes in Garudimimus has many features that are widely spread throughout theropods in general. To them is relegated the development of digit I, the shortened metatarsus, and the lack of proximal compression of metatarsal III. These signs testify to the primitive nature of garudimimids, inasmuch as ornithomimids exhibit features of much higher specialization.
Source: Polyglot Paleontologist
Barsbold, 1981
Time
Cretaceous Late Cenomanian Turonian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Ornithomimosauria Garudimimidae
Diet
?
Fossilsite
Baynshirenskaya Svita, Baishin Tsav, Omnogov, Mongolia
Info
Genus - Typespecies - Skull
Skull with associated incomplete poscranium. The family Garudimimidae includes but one species, Garudimimus brevipes. G.brevipes has a skull that does not differ in its basic structure from that in ornithomimid species, but the infratemporal fenestra is reduced and the quadrate is more vertical. This species is also very primitive in many other respects among ornithomimmosaurians. The manus is unknown. Retained its first pedal digit.
Etymology
After the bird Garudi in the mythology of eastern peoples. | From brevis, Latin “short”; pes, Latin “foot”.
Species type
Garudimimus brevipes Barsbold, gen. et sp. nov.
Genus composition
Monotypic species
Distribution
Early Senonian, South Eastern Mongolia.
Holotype
#100/13, GIN AN MNR; skull; fragments of axial skeleton, pelvis and incomplete posterior limbs; lower Senonian, Bayanshipensk suite, Bayshin- Tsav location, South Eastern Mongolia.
Material
Holotype Description
Ventral part of the base of the open basisphenoidal capsule in front of the basipterygoidal processes (to which it passed without interruption) connected with the medial edges of the pterygoids, 7 dorsally, but covering the interpterygoidal cavity. Such additional articulation of the capsule with thepterygoids must have blocked the basipterygoidal articulation, denying it mobility. Interpterygoidal cavity is considerably reduced. Entering openings of the parabasal canals are located immediately in front of the horizontally directed and shortened basipterygoidal processes. Anteriorly and laterally from the openings, adjoin the pterygoids, lining their areas next to the edge. The epipterygoids in the shape of V-shaped lamella, are ventrally wider. In the lower jaw the lamella ends in a V-shape, without reaching the symphysis. The coronary is absent. The retroarticular process is widened, with dorsally open large recess, which attached m. depressor mandibulae. The medial edge of the process was highly thickened and, apparently, rested against the base of the quadrate, interfering, as in the case of the dromesaurid (Colbert and Russell, 1969) to the extreme displacement of the lower jaw. The dorsal and sacral (caudal are not in the collection) vertebrae have no pleurocoels.
There are six sacral vertebrae. The distal end of the left rib is separated from the diapophysis and leans against the medial surface of the ilium. The ilium is high, a little shorter than the pubis, with narrowed posterior wing, the upper and lower edge of which are sub-parallel. The femur is insignificantly shorter than the tibia. III tarsal element lay on the proximal articular surfaces of predominantly the III and only partially the II metatarsal bones. IV tarsal element fully articulated with same named metatarsal bone. In the foot three basic (II, III, IV) and two residual (I, V) metatarsals. I metatarsal has a reduced, distally V-shaped trunk, adjacent to the II metatarsal. Distal metatarsal is the shortest and thickest, its proximal end is 8 anteriorly widened, posteriorly slightly compressed.
The III is the most thickened and elongated, in the distal part slightly curved, in the proximal part slightly compressed. IV metatarsal in length occupied intermediary position between II and III, its proximal end is widened. Distal head of the bones with convex articular surfaces, are slightly divided sagitally by a furrow. V metatarsal is highly reduced to a narrow, laterally compressed residual element, attached to the IV metatarsal. The first toe is the most reduced, its ungula is noticeably compressed from the sides. Phalanges of each of the remaining toes decreased progressively in the distal direction, which is best expressed in the fourth toe, the ungula of which has a flattened ventral surface (in the second and third toes the unguals are not known).
Observations
According to the development of the basisphenoidal capsule, which is open posteriorly, the skull of Gallimimus is in many aspects similar to that of Gallimimus. It was possible to establish that in the latter that the so-called basipterygoidal branches of the pterygoids (Osmolska et al., 1972) in reality are the epipterygoids. The same type of skull structure in Garudimimus and Gallimimus allow the generalization of the development of the basisphenoidal capsule and the blocked basipterygoidal articulation for the whole group (there is a possibility of the presence of the capsule in one of the American species, see Parks, 1933; Osmolska et al., 1972). Parabasal canals have similar structures, and most likely were a distinguishing characteristic for the whole group. The capsule (closed type), the supposed blocked basipterygoidal articulation and the horizontal orientation of the basipterygoidal processes in the saurornithoidids (Barsbold, 1974) create an expectation of the development of 9 the parabasal canals also in this family of theropods. The shortness of the ilium and the metatarsus, the lack of compression of the III metatarsal and the development of the first toe differentiate Garudimimus from all representatives of the progressive branch of the ornithomimosaurs.
Geologic age
Lower Senonian, Bayasirensk suite. Location: South Eastern Mongolia, location Bay-shin-tsav.
Holotype Barsbold 1983
PST GIN AN MNR no. 100/13; skull, fragments of the axial skeleton, pelvis and incomplete limbs.
Description
Basisphenoid capsule open posteriorly, connected with the medial edges of the pterygoid, covering the reduced interpterygoid cavity dorsally. Basipterygoid articulation supposedly immobile. Incurrent opening of the parabasal canal limited laterally by the ventral edge of the quadrate flange of the pterygoid, posteriorly by the pterygoid process, and medially and ventrally by the basisphenoid capsule.
The canal is shortened and directed initially ventrally, then enters into the space between the quadrate flange of the pterygoid and the base of the basisphenoid capsule. From here, there is possibly a passage lining the pterygoid capsule more dorsally, between the front posterior edge of the quadrate flange and the ventrolateral part of the capsule. The ectopterygoid has the appearance of a ventrally widened, V-shaped lamina. In the lower jaw, the splenial has a V-shaped end and does not reach the symphysis.
The coronoid is absent. The retroarticular process is widened, with an indentation open dorsally. Dorsal and sacral vertebrae lack pleurocoels. Six sacral vertebrae. In the first sacral, the rib is separated from the diapophysis and contacts the medial surface of the [ilium] with its distal end. The [ilium] is high anteriorly, has a dorsal edge with a rounded, convex shape, and is slightly shorter than the pubis.
The posterior process of the ilium is narrowed, with parallel dorsal and ventral edges. Femur slightly shorter than the tibia. Two tarsals (3 and 4), of which 3 rested mostly on the proximal articular surface of metatarsal III and only partly on that of II. Tarsal 4 fully connected with metatarsal IV. Five compositional elements in the pes: three basic (II, III, IV) and two residual (I, V) metatarsals.
Metatarsal I with reduced, distally V-shaped shaft, laterally adjoining metatarsal II. The distal head has a convex articular surface, directed ventromedially. Of the three basic elements, metatarsal II is more shortened, its proximal end is widened anteriorly, and it is narrowed posteriorly. Metatarsal III is the most elongated and thickened, slightly curved distally, almost not highly compressed proximally, and fully divides the adjoining metatarsals. Metatarsal IV is intermediate in length between II and III, with a broad proximal end.
The distal end of the bone has convex articular surfaces divided weakly by a furrow. Metatarsal V is highly reduced to the condition of a narrow, laterally compressed rudiment, attached to the side of metatarsal IV. Pedal digit I is the most reduced, with its ungual phalanx notably laterally compressed. The phalanges of each digit are progressively smaller distally, a trend most clearly expressed in digit IV. Its ungual phalanx (the ungual phalanges are not known for the other digits) has a flattened ventral surface.
Discussion
The skull of Garudimimus is similar in many ways to that of Gallimimus , especially in the development and construction of the basisphenoid capsule, open posteriorly. In the latter, the epipterygoids were successfully defined as so-called basipterygoid rami of the pterygoid (Osmólska, Roniewicz, and Barsbold, 1972).
The parabasals are similarly constructed in representatives of both families. The shortening of the ischium and metatarsus, the lack of compression of metatarsal III and its complete separation of II and IV (which do not contact each other), and the connection of tarsal 3 mostly with the proximal articular surface of metatarsal III serve as basic differentiating signs of garudimimid features.
The laterally closed basisphenoid capsule, supposedly blocked by the pterygoid articulation, and a similar type of parabasal canal are characteristic of saurornithoidids, in addition to Garudimimus and Gallimimus . The construction of the pes in Garudimimus has many features that are widely spread throughout theropods in general. To them is relegated the development of digit I, the shortened metatarsus, and the lack of proximal compression of metatarsal III. These signs testify to the primitive nature of garudimimids, inasmuch as ornithomimids exhibit features of much higher specialization.
Source: Polyglot Paleontologist