Harpymimus
Encyclopedia
Harpymimus is a basal ornithomimosaurian theropod dinosaur
from the Early Cretaceous
Period of what is now Mongolia
. Unlike later, more derived ornithomimosaurs, Harpymimus still possessed teeth, although they appear to have been restricted to the dentary of the lower jaw.
. In 1984 this was named and shortly described by Rinchen Barsbold and Altangerel Perle
as the type
and only species
of the new genus
Harpymimus: Harpymimus okladnikovi. The generic name Harpymimus is a reference to the fearsome Harpy
of Greek mythology
and derived from Greek ἅρπυια (harpyia), "Harpy", and μῖμος (mimos), "mimic". The specific name honours the late Soviet archeologist Alexey Pavlovich Okladnikov.
The holotype
specimen IGM 100/29 (Mongolian Academy of Sciences, Ulan Bator, Mongolia) consists of an almost complete and articulated but compressed skeleton, lacking only portions of the pectoral girdle, pelvic girdle, and hindlimbs. It was recovered in the Dundgovi Aimag
(Eastern Gobi
Province), from an exposure of the Shinekhudug Formation (Shinekhudag Svita
or Shinekhudukskaya Svita) dating to the Hauterivian
to Barremian
; earlier stratification suggested a younger, Albian
, age. Other dinosaur
s collected from the Shinekhudug Formation in Dundgovi include the ceratopsia
n Psittacosaurus mongoliensis
.
surface of a ridge on the shoulder blade (scapula
) above the shoulder joint, a low ridge above a distinctive depression along back edge of the shoulder blade, and a small but deep collateral ligament fossa
on the lateral condyle
of metacarpal III (a hand bone).
The skull of the type specimen of Harpymimus is virtually complete, but badly crushed, obscuring some anatomical detail. There is evidence of a beak
covering the upper jaw which, in concert with the dentary teeth, was likely employed for grasping and holding food. Its general appearance was much like that of later ornithomimosaurs (long-necked, long arms with sharp grasping claws, and long legs). The teeth of Harpymimus differ from those of another basal ornithomimosaur, Pelecanimimus polyodon
, in that they are restricted to the dentary, are cylindrical and separated by interdental plates, and number at least ten and perhaps eleven per side. Pelecanimimus possessed per side seventy-five dentary teeth in the lower jaw, as well as an additional thirty-seven teeth in the upper jaw (maxilla
and premaxilla
). The small teeth of Harpymimus were probably used only for grabbing and holding food items, unlike those of many other theropods, which were adapted to cutting or piercing prey. Of all the known ornithomimosaurs, only Harpymimus and Pelecanimimus retained teeth, a trait which is primitive (plesiomorphic) for the clade
Orithomimosauria. Other basal traits are the very short first metacarpal in the hand and a third metatarsal that, though pinched at the top, is at that point not excluded form the front surface of the metatarsus
, so that the foot is not arctometatarsalian.
The length of the skull is approximately 262 mm, more than twice its approximate height and less than half the length of the neck (approximately 600 mm).
of Garudimimus brevipes
plus Ornithomimidae, yet is more derived than Pelecanimimus polyodon. According to these researchers, the conclusions of the analysis supported the model that ornithomimosaurs originated in either eastern Asia
or in Europe
prior to the Barremian stage of the Early Cretaceous (130-125 million years ago), then migrated to North America
during or at some time before the Late Cretaceous.
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
Period of what is now Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
. Unlike later, more derived ornithomimosaurs, Harpymimus still possessed teeth, although they appear to have been restricted to the dentary of the lower jaw.
Discovery and naming
In 1981, a Soviet-Mongolian expedition uncovered a theropod skeleton in the Gobi DesertGobi Desert
The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...
. In 1984 this was named and shortly described by Rinchen Barsbold and Altangerel Perle
Altangerel Perle
Altangerel Perle is a Mongolian palaeontologist.He is employed at the National University of Mongolia. He has described species such as Goyocephale lattimorei, Achillobator giganticus and Erlikosaurus andrewsi. He has been honored by Polish palaeontologist Halszka Osmólska, who named the species...
as the type
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
and only species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of the new genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Harpymimus: Harpymimus okladnikovi. The generic name Harpymimus is a reference to the fearsome Harpy
Harpy
In Greek mythology, a harpy was one of the winged spirits best known for constantly stealing all food from Phineas...
of Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
and derived from Greek ἅρπυια (harpyia), "Harpy", and μῖμος (mimos), "mimic". The specific name honours the late Soviet archeologist Alexey Pavlovich Okladnikov.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen IGM 100/29 (Mongolian Academy of Sciences, Ulan Bator, Mongolia) consists of an almost complete and articulated but compressed skeleton, lacking only portions of the pectoral girdle, pelvic girdle, and hindlimbs. It was recovered in the Dundgovi Aimag
Dundgovi Province
Dundgovi is one of the 21 aimags of Mongolia. It is located in the south of the country, approximately south of Ulaanbaatar. Its capital is Mandalgovi.- Climate :...
(Eastern Gobi
Gobi Desert
The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...
Province), from an exposure of the Shinekhudug Formation (Shinekhudag Svita
Shinekhudag Svita
The Shinekhudag Svita is a geological formation in Dundgov, Mongolia whose strata date back to the Early Cretaceous. Dinosaur remains have been recovered from it.-Vertebrate paleofauna:...
or Shinekhudukskaya Svita) dating to the Hauterivian
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 136.4 ± 2 Ma and 130 ± 1.5 Ma...
to Barremian
Barremian
The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...
; earlier stratification suggested a younger, Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
, age. Other dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s collected from the Shinekhudug Formation in Dundgovi include the ceratopsia
Ceratopsia
Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs which thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7...
n Psittacosaurus mongoliensis
Psittacosaurus
Psittacosaurus is a genus of psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period of what is now Asia, about 130 to 100 million years ago. It is notable for being the most species-rich dinosaur genus...
.
Description
Harpymimus was for the first time extensively described in a dissertation by Yoshitsugu Kobayashi in 2004. In a 2005 article, Kobayashi and Barsbold diagnosed Harpymimus based on a number of anatomical characteristics, including eleven teeth in the front of the lower jaw (dentary), the transition between anterior and posterior tail vertebrae taking place at the eighteenth caudal, a triangular-shaped depression above the dorsalDorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
surface of a ridge on the shoulder blade (scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
) above the shoulder joint, a low ridge above a distinctive depression along back edge of the shoulder blade, and a small but deep collateral ligament fossa
Fossa (anatomy)
In anatomical terminology, fossa has come to mean a depression or hollow, in general, in a bone. Other parts of the body may be involved, for example, the antecubital fossa...
on the lateral condyle
Lateral condyle
Lateral condyle can refer to:* Lateral condyle of tibia* Lateral condyle of femur* Lateral condyle on metatarsal...
of metacarpal III (a hand bone).
The skull of the type specimen of Harpymimus is virtually complete, but badly crushed, obscuring some anatomical detail. There is evidence of a beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
covering the upper jaw which, in concert with the dentary teeth, was likely employed for grasping and holding food. Its general appearance was much like that of later ornithomimosaurs (long-necked, long arms with sharp grasping claws, and long legs). The teeth of Harpymimus differ from those of another basal ornithomimosaur, Pelecanimimus polyodon
Pelecanimimus
Pelecanimimus is a genus of basal ornithomimosaurian theropod dinosaur from the Early Cretaceous of Spain...
, in that they are restricted to the dentary, are cylindrical and separated by interdental plates, and number at least ten and perhaps eleven per side. Pelecanimimus possessed per side seventy-five dentary teeth in the lower jaw, as well as an additional thirty-seven teeth in the upper jaw (maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
and premaxilla
Premaxilla
The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....
). The small teeth of Harpymimus were probably used only for grabbing and holding food items, unlike those of many other theropods, which were adapted to cutting or piercing prey. Of all the known ornithomimosaurs, only Harpymimus and Pelecanimimus retained teeth, a trait which is primitive (plesiomorphic) for the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Orithomimosauria. Other basal traits are the very short first metacarpal in the hand and a third metatarsal that, though pinched at the top, is at that point not excluded form the front surface of the metatarsus
Metatarsus
The metatarsus or metatarsal bones are a group of five long bones in the foot located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side : the first, second, third, fourth, and fifth...
, so that the foot is not arctometatarsalian.
The length of the skull is approximately 262 mm, more than twice its approximate height and less than half the length of the neck (approximately 600 mm).
Phylogeny
Harpymimus was originally assigned to the Harpymimidae. In their 2005 paper, Kobayashi and Barsbold also conducted a detailed cladistic analysis of Harpymimus and determined that Harpymimus is basal to the cladeClade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of Garudimimus brevipes
Garudimimus
Garudimimus is a basal ornithomimosaurian theropod dinosaur from the Upper Cretaceous of Mongolia.-Discovery and naming:...
plus Ornithomimidae, yet is more derived than Pelecanimimus polyodon. According to these researchers, the conclusions of the analysis supported the model that ornithomimosaurs originated in either eastern Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
or in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
prior to the Barremian stage of the Early Cretaceous (130-125 million years ago), then migrated to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
during or at some time before the Late Cretaceous.