Gwyneddosaurus
Encyclopedia
Gwyneddosaurus is an extinct genus
of aquatic tanystropheid
reptile. The type species
, G. erici was described in 1945 by Wilhelm Bock, who identified it as a coelurosauria
n dinosaur
related to Podokesaurus
(at the time, "podokesaurids" were thought to be coelurosaurians). Its remains were found in the Upper Triassic Lockatong Formation
of Montgomery County
, eastern Pennsylvania
, and include skull fragments, several vertebra, ribs, gastralia
, partial shoulder and hip bones, and several forelimb and hindlimb elements found in soft shale
. The type specimen
is ANSP
15072. It was discovered by Bock's four-year-old son. It was not a large animal; the type skeleton was estimated by Bock as 18 centimetres (7.1 in) long, and its thigh bone
was only 23 millimeters long (0.91 in).
Friedrich von Huene
assigned the animal to Protorosauria
in 1948 as the smallest known member of the group, finding it to be most like Macrocnemus
. Steel (1970) classified it as a theropod dinosaur
, whereas Olsen and Baird (1986) identified it as a chimera
of mixed remains from a coelacanth
and possibly the tanystropheid Tanytrachelos; Olsen and Flynn (1989) later modified this interpretation, describing the type specimen of Gwyneddosaurus as a "gastric ejection" (regurgitation) composed of Tanytrachelos bones and possibly scraps of a coelacanth. They noted that this would make Gwyneddosaurus a senior synonym
of Tanytrachelos, and recommended conserving
the younger but better-represented 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...
of aquatic tanystropheid
Tanystropheus
Tanystropheus , was a 6 metre long reptile that dated from the Middle Triassic period. It is recognisable by its extremely elongated neck, which measured 3 metres long - longer than its body and tail combined. Despite this length, it had only ten neck vertebrae, each quite long...
reptile. The type species
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...
, G. erici was described in 1945 by Wilhelm Bock, who identified it as a coelurosauria
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...
n 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...
related to Podokesaurus
Podokesaurus
Podokesaurus was a small carnivorous dinosaur of the Early Jurassic Period , and as such is one of the earliest known dinosaurs to inhabit the eastern United States . The small, bipedal carnivore was about 90 cm long and 0.3 m tall...
(at the time, "podokesaurids" were thought to be coelurosaurians). Its remains were found in the Upper Triassic Lockatong Formation
Lockatong Formation
The Triassic Lockatong Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It is named after the Lockatong Creek in Hunterdon County, New Jersey.-Description:...
of Montgomery County
Montgomery County, Pennsylvania
Montgomery County is a county located in the U.S. state of Pennsylvania, in the United States. As of 2010, the population was 799,874, making it the third most populous county in Pennsylvania . The county seat is Norristown.The county was created on September 10, 1784, out of land originally part...
, eastern Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, and include skull fragments, several vertebra, ribs, gastralia
Gastralium
Gastralia are dermal bones found in the ventral body wall of crocodilian and Sphenodon species. They are found between the sternum and pelvis, and do not articulate with the vertebrae...
, partial shoulder and hip bones, and several forelimb and hindlimb elements found in soft shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
. The type specimen
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...
is ANSP
Academy of Natural Sciences
The Academy of Natural Sciences of Drexel University, formerly Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the New World...
15072. It was discovered by Bock's four-year-old son. It was not a large animal; the type skeleton was estimated by Bock as 18 centimetres (7.1 in) long, and its thigh bone
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
was only 23 millimeters long (0.91 in).
Friedrich von Huene
Friedrich von Huene
Friedrich von Huene was a German paleontologist who named more dinosaurs in the early 20th century than anyone else in Europe.-Biography:...
assigned the animal to Protorosauria
Protorosaurus
Protorosaurus , a lizard-like reptile of the order Prolacertiformes, is the earliest known archosauromorph. It lived during the Late Permian period in Germany. In 1914, a new ceratopsian dinosaur found by Lawrence Lambe was again given the name Protorosaurus...
in 1948 as the smallest known member of the group, finding it to be most like Macrocnemus
Macrocnemus
Macrocnemus is an extinct genus of prolacertiform reptile from the Middle Triassic of Europe. Two species have been named, the type species M. bassanii and the species M. fuyuanensis....
. Steel (1970) classified it as a theropod 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...
, whereas Olsen and Baird (1986) identified it as a chimera
Chimera (paleontology)
In paleontology, a chimera is a fossil which was reconstructed with elements coming from more than a single species of animal. A now classic example of chimera is Protoavis.-List of paleontological chimeras:*Brontosaurus*Lametasaurus...
of mixed remains from a coelacanth
Coelacanth
Coelacanths are members of an order of fish that includes the oldest living lineage of Sarcopterygii known to date....
and possibly the tanystropheid Tanytrachelos; Olsen and Flynn (1989) later modified this interpretation, describing the type specimen of Gwyneddosaurus as a "gastric ejection" (regurgitation) composed of Tanytrachelos bones and possibly scraps of a coelacanth. They noted that this would make Gwyneddosaurus a senior synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
of Tanytrachelos, and recommended conserving
Conserved name
A conserved name or nomen conservandum is a scientific name that has specific nomenclatural protection. Nomen conservandum is a Latin term, meaning a "name which should be conserved"...
the younger but better-represented genus.