Deinodon
''Deinodon'' (Greek for "terrible tooth") is a dubious tyrannosaurid dinosaur genus containing a single species, ''Deinodon horridus''. ''D. horridus'' is known only from a set of teeth found in the Late Cretaceous Judith River Formation of Monta ...
''") is a
wastebasket taxon
Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...
and a
dubious
Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, unable to be certain of any of them.
Doubt on an emotional level is indecision between belief and disbelief. It may involve uncertainty, ...
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
from the
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma.
Geology
Pro ...
(
Barremian
The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded ...
to
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...
stages
Stage or stages may refer to:
Acting
* Stage (theatre), a space for the performance of theatrical productions
* Theatre, a branch of the performing arts, often referred to as "the stage"
* ''The Stage'', a weekly British theatre newspaper
* S ...
) from the
Xinlong Formation
The Xinlong Formation (sometimes called the "Napai Formation", or misspelt as "Napan Formation") is an Early Cretaceous geologic formation in Guangxi, southern China.Napai Basin of
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
. Two species have been formally identified (with a third informal species), all three known only from tooth fragments, showing no diagnostic features, making them difficult to classify, though they may belong to a
carnosaur
Carnosauria is an extinct large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as ''Gig ...
. At least some of the referred species may represent basal
carcharodontosaurid
Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae ...
theropods similar to ''
Acrocanthosaurus
''Acrocanthosaurus'' ( ; ) is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, ' ...
''.
The
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
, ''P. mongoliense'', was described by
Henry Fairfield Osborn
Henry Fairfield Osborn, Sr. (August 8, 1857 – November 6, 1935) was an American paleontologist, geologist and eugenics advocate. He was the president of the American Museum of Natural History for 25 years and a cofounder of the American Euge ...
in 1924. A second species, ''P. kwangshiensis'', was named in 1975. "P. tibetensis" has not been formally described, and it may have belonged to its own, separate
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
.
Species
*''P. mongoliense'' (Osborn, 1924) is known from a single tooth, collected around 1923 and described by Henry Fairfield Osborn in a 1924 paper, where he also described several other
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
s and
sauropods
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...
discovered in
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
.Full reference: H. F. Osborn. 1924. Sauropoda and Theropoda from the Lower Cretaceous of Mongolia. ''American Museum Novitates'' 128:1-7 The holotype of ''P. mongoliense'', which is the holotype for the entire genus, is AMNH 6265, a single tooth collected from the Oosh Formation. Some scientists have considered ''P. mongoliense'' to have been a
carnosaur
Carnosauria is an extinct large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as ''Gig ...
.
*''P. kwangshiensis'' (You ''et al.'', 1975) is known from four incomplete teeth and a tibia, found in the
Xinlong Formation
The Xinlong Formation (sometimes called the "Napai Formation", or misspelt as "Napan Formation") is an Early Cretaceous geologic formation in Guangxi, southern China.China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
.L.-h. Hou, H.-k. Yeh, and X.-j. Zhao. 1975. Fossil reptiles from Fusui, Kwangshi. Vertebrata PalAsiatica 13(1):24-33 It can confidently be identified to
Theropoda
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally ca ...
but it was probably not the same type of theropod as ''P. mongoliense''. It could represent a carcharodontosaurid closely related to ''
Acrocanthosaurus
''Acrocanthosaurus'' ( ; ) is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, ' ...
vertebra
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
found in the
Hettangian
The Hettangian is the earliest age and lowest stage of the Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (My ...
Daye Group
The Daye Group is a geological formation in China. It dates back to the Hettangian-PliensbachianWeishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (e ...
in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, this species was probably a
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
but it most likely did not belong to the same animal as ''P. mongoliense'' and it may have belonged to its own, entirely separate
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
. It is geographically present in Xizang Zizhiqu, China.Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): ''The Dinosauria'', 2nd, Berkeley: University of California Press. Pp. 534–535. .