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{{Short description|Extinct genus of reptiles}}
{{Short description|Extinct genus of diapsid reptiles}}
{{Automatic taxobox
{{Automatic taxobox
| fossil_range = [[Early Cretaceous]], {{Fossil range|Aptian}}
| fossil_range = [[Early Cretaceous]] ([[Aptian]]), {{Geological range|125|99.6}}
| image = Tchoiria skeleton.PNG
| image = Tchoiria klauseni.jpg
| image_caption = ''Tchoiria klauseni'' holotype fossil
| image_caption = ''T. klauseni'' reconstruction
| taxon = Tchoiria
| taxon = Tchoiria
| authority = Efimov, [[1975 in paleontology|1975]]
| authority = Efimov, [[1975 in paleontology|1975]]
| subdivision = *†''T. namsari'' <small>Efimov, 1975 ([[type species|type]])</small>
|subdivision =
*†''T. namsari'' <small>Efimov, 1975 ([[type species|type]])</small>
*†''T. klauseni'' <small>Ksepka ''et al.'', [[2005 in paleontology|2005]]</small>
*†''T. klauseni'' <small>Ksepka ''et al.'', [[2005 in paleontology|2005]]</small>
}}
}}


'''''Tchoiria''''' ({{IPAc-en|ˈ|tʃ|ɔɪ|r|i|ə}}''''')''''' is a [[genus]] of [[Neochoristodera|neochoristoderan]] [[reptile]] from the [[Cretaceous|Early Cretaceous]] of [[Mongolia]]. The name ''Tchoiria'' comes from the city of [[Choir, Mongolia|Choir]] which is nearby to where the [[holotype]] was found.<ref name=":0">{{Cite journal |last=Efimov |first=M.B. |date=1975 |title=Khampsozavrid iz Nizhnego Mela Mongolii |journal=Iskopaemaya Fauna I Flora Mongolii. Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya, Trudy |volume=2 |pages=84-93}}</ref> ''Tchoiria'' is thought to have a similar diet to another neochoristoderan reptile, [[Champsosaurus]], due to morphology of the skull. It would hunt in freshwater environments, like the living [[Gharial|gharials]], where it would prey on many different types of fish and turtles.<ref>{{Citation |last=Evans |first=Susan E. |title=A History of an Extinct Reptilian Clade, the Choristodera: Longevity, Lazarus-Taxa, and the Fossil Record |date=1993 |url=https://doi.org/10.1007/978-1-4615-2878-4_8 |work=Evolutionary Biology |pages=323–338 |editor-last=Hecht |editor-first=Max K. |place=Boston, MA |publisher=Springer US |language=en |doi=10.1007/978-1-4615-2878-4_8 |isbn=978-1-4615-2878-4 |access-date=2023-03-02 |last2=Hecht |first2=Max K. |editor2-last=MacIntyre |editor2-first=Ross J. |editor3-last=Clegg |editor3-first=Michael T.}}</ref><ref name=":3">{{Cite book |last=Masaki. |first=Matsukawa, |url=http://worldcat.org/oclc/1039765867 |title=Early Cretaceous terrestrial ecosystems in East Asia based on food-web and energy-flow models |oclc=1039765867}}</ref>
[[File:Tchoiria fossil.jpg|thumb|left|Front view of ''T. klauseni'' holotype]]

<!--[[File:Tchoiria klauseni.jpg|thumb|left|upright|Restoration of ''T. klauseni'']]-->
== History of research ==
'''''Tchoiria''''' is a [[genus]] of [[simoedosauridae|simoedosaurid]] [[choristodera|choristodere]], a type of [[crocodile]]-like aquatic reptile.<ref name=DTKetal05>{{cite journal |last= Ksepka |first=D. T. |author2=K.-Q. Gao |author3= Norell, M. A. |year=2005 |title=A new choristodere from the Cretaceous of Mongolia |journal=American Museum Novitates |issue=3468 |pages=1–22 |url=http://digitallibrary.amnh.org/dspace/bitstream/2246/2778/1/N3468.pdf |doi=10.1206/0003-0082(2005)468<0001:ancftc>2.0.co;2}}</ref> Fossils of this genus have been found in [[Early Cretaceous]]-age rocks in Mongolia. Four species have been named, but two have been given their own genera. The [[type species]] is ''T. namsari'', [[holotype|based on]] [[Paleontological Institute of Russian Academy of Sciences|PIN]]&nbsp;3386/1, a partial skull and skeleton discovered in the [[Aptian]]-age [[Lower Cretaceous]] Hühteeg Formation at Hüren Dukh, central [[Mongolia]]. Two other species were named from this locality, with both later being reassigned: ''T. egloni'', now ''[[Irenosaurus|Irenosaurus egloni]]''; and ''T. magnus'', now ''[[Ikechosaurus|Ikechosaurus magnus]]''.<ref name=MEGS00>{{cite book |last=Efimov |first=Mikhail B. |author2=Storrs, Glenn W. |editor=Benton, Michael J. |editor-link=Benton, Michael J. |editor2=Shishkin, Mikhail A. |editor3=Unwin, David M. |editor4=Kurochkin, Evgenii N. |title=The Age of Dinosaurs in Russia and Mongolia |year=2000 |publisher=Cambridge University Press |location=Cambridge |isbn=0-521-55476-4 |pages=390–401 |chapter=Choristodera from the Lower Cretaceous of northern Asia }}</ref> A fourth species, ''T. klauseni'', was named from a partial skull and skeleton found in rocks of roughly the same age farther west in Mongolia.<ref name=DTKetal05/>
[[File:Tchoiria klauseni Skull.jpg|left|thumb|Dorsal view of the skull of ''T. klauseni'']]
''Tchoiria'' remains were first recovered as a part of the [[Joint Soviet-Mongolian Expeditions]] which took place in the [[Gobi Desert]]. They were described by Mikhail B. Efimov in 1975; basing his description on a partial cranium and some parts of the postaxial skeleton found at the [[Huhteeg formation|Hühteeg Formation]]. He would make the type species ''T. namsari''.<ref name=":0" /><ref name=":1">{{Cite book |url=https://www.worldcat.org/oclc/53710242 |title=The age of dinosaurs in Russia and Mongolia |date=2003 |publisher=Cambridge University Press |others=M. J. Benton |isbn=0-521-54582-X |location=Cambridge |oclc=53710242}}</ref> Efimov would name two other ''Tchoiria'' species in the latter 20<sup>th</sup> century, ''T. magnus'' in 1979 and ''T. egloni'' in 1983. Both taxa were based on postcranial fossils that were also found in the Hühteeg Formation. These would later be redescribed as new members of neochoristodera by Efimov.<ref>{{Cite web |title=Tchoiria |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=37789 |website=Paleobiology Database}}</ref><ref name=":1" /> The second valid species of ''Tchoiria'' would be named in 2005 by [[Daniel T. Ksepka|Danial T. Ksepka]]. ''T. klauseni'' would be based on a partial skull and some postcranial material found at the Two Volcanoes locality of southern Mongolia.<ref name=":2">{{Cite journal |last=Kspeka |first=D.T. |last2=Evans |first2=S.E. |last3=Norell |first3=M.A. |date=2005 |title=A New Choristodere from the Cretaceous of Mongolia |url=https://bioone.org/journals/american-museum-novitates/volume-2005/issue-3468/0003-0082(2005)468%3c0001%3aANCFTC%3e2.0.CO%3b2/A-New-Choristodere-from-the-Cretaceous-of-Mongolia/10.1206/0003-0082(2005)468%3C0001:ANCFTC%3E2.0.CO;2.full |journal=American Museum Novitates |volume=3468 |issue=1}}</ref> Efimov would place ''Tchoiria'' in the order [[choristodera]] in his original description.<ref name=":0" /> Later it would also be placed in suborder neochoristodera in 2007 by Ryoko Matsumoto. Matsumoto would declare the suborder [[Monophyly|monophyletic]] in his paper on the choristodere [[Monjurosuchus]].<ref>{{Cite book |last=Ryoko. |first=Matsumoto, |url=http://worldcat.org/oclc/999165005 |title=The choristoderan reptile Monjurosuchus from the Early Cretaceous of Japan |date=2007 |oclc=999165005}}</ref> ''Tchoiria'' was the first choristodere known from Asia and has been used in many morphological and environmental studies based on the order since its original description.<ref name=":0" /><ref name=":1" />

== Description: ==

=== '''Cranial''' ===
[[File:Tchoiria skeleton.PNG|thumb|''T. klauseni'' holotype from the Dinosaurios del desierto de Gobi exhibition in [[Chile]]]]
The skull of ''Tchoiria'' is similar to other neochoristoderes in having a flared postorbital region, an elongated and narrow snout, and having small orbits. The skull is also very flattened like other members of neochoristodera. The nasals have also fused into a single element. The teeth of ''Tchoiria'' are conical in shape and decrease in size further back in the skull. They also curve medially and have vertical, parallel lines. The orbits have a raised rim surrounding them and are very rough in texture.<ref name=":2" /> Like other diapsid reptiles, ''Tchoiria'' has two temporal fenestrae behind the orbit. The snout is shorter than the ''Champsosaurus'' but still longer than other choristoderes. Other skull traits include a shortened lower jaw symphysis, a broader and shorter rostrum, and the posterior displacement of mandibular articulation.<ref name=":0" /><ref name=":1" />

=== Postcranial ===
A complete set of vertebrae for ''Tchoiria'' have not been fully preserved but specimens of each section have been described. The vertebrae have amphiplatyan-style centrum and a closed notochordal canal. The dorsal vertebrae have small processes below their respective postzygapophyses. These are similar to the processes seen in both ''[[Simoedosaurus|Simeodosaurus]]'' and ''[[Ikechosaurus]].''<ref name=":2" /><ref>{{Cite journal |last=Evans |first=Susan E. |last2=Manabe |first2=Makoto |date=1999 |title=A choristoderan reptile from the Lower Cretaceous of Japan |journal=Special papers in Palaeontology}}</ref> The caudal vertebrae have the unique trait of having a deep groove bordered by ventral flanges; a trait seen in choristoderes but not usually in neochoristoderes. The caudal vertebrae also have unfused [[Haemal arch|hemal arches]]. ''Tchoiria'' had similar [[gastralia]] to other members of its suborber. The limbs of ''Tchoiria'' are very fragmentary. Parts of the shoulder girdle are preserved and shows that they would be long and narrow. Besides a single femur, the rest of the hindlimbs are unknown.<ref name=":2" />

== Species ==
[[File:Ikechosaurus sp. NMNS.jpg|thumb|Ikechosaurus, formerly T. egloni]]
There has been a total of four species of ''Tchoiria'' named, but as of 2023, only two are considered valid. ''T. magnus'' was moved to the genus ''Ikechosaurus'' in 1981 and ''T. egloni'' was moved to the new genus ''[[Irenosaurus]]'' in 1988.<ref name=":1" /> These two taxa were moved due to morphological differences when compared to the ''T. namsari''.

''T. namsari'' is the type species and is known from the Hühteeg Formation of Mongolia. The other species, ''T. klauseni'' is known from the Two Volcanoes locality of southern Mongolia. ''T. klauseni'' was separated from ''T. namsari'' by the number of teeth in both the maxilla and the dentary. ''T. namsari'' is known to have more teeth, 60 in the maxilla and 17 in the symphyseal portion of the dentary, while ''T. klausnei'' has a smaller number of them, 34 in the maxilla and 12 in the symphyseal portion of the dentary.<ref name=":2" />

== Classification ==
''Tchoiria'' has been placed in neochoristodera, which is a clade within choristodera. The group first appeared in the Early Cretaceous of Asia and were successful due to the absence of [[Crocodile|crocodiles]]. Later in the Cretaceous and the early [[Paleocene]], neochoristoderans needed to become more specialized because of their shared ecosystem with a wide range of crocodiles.<ref>{{Cite journal |last=Matsumoto |first=R. |last2=Evans |first2=S. E. |date=2010 |title=Choristoderes and the freshwater assemblages of Laurasia |url=http://revistas.ucm.es/index.php/JIGE/article/view/JIGE1010220253A |journal=Journal of Iberian Geology |volume=36 |issue=2 |pages=253–274 |doi=10.5209/rev_JIGE.2010.v36.n2.11 |issn=1698-6180}}</ref>
[[File:Champsosaurus BW.jpg|thumb|An example of [[neochoristodera]], ''[[Champsosaurus]]'']]
The phylogenic tree below comes from Dong et al. (2020) shows neochoristodera and their relationship to other members of choristodera.<ref>{{Cite journal |last=Dong |first=Liping |last2=Matsumoto |first2=Ryoko |last3=Kusuhashi |first3=Nao |last4=Wang |first4=Yuanqing |last5=Wang |first5=Yuan |last6=Evans |first6=Susan E. |date=2020-08-02 |title=A new choristodere (Reptilia: Choristodera) from an Aptian–Albian coal deposit in China |url=https://doi.org/10.1080/14772019.2020.1749147 |journal=Journal of Systematic Palaeontology |volume=18 |issue=15 |pages=1223–1242 |doi=10.1080/14772019.2020.1749147 |issn=1477-2019}}</ref>
{{Clade|style={{clade
|1=''[[Cteniogenys]]'' sp.
|2={{clade
|1=''[[Heishanosaurus]] pygmaeus''
|2=''[[Coeruleodraco]] jurassicus''
|3={{clade
|label1=[[Neochoristodera]]
|1={{clade
|1=''[[Ikechosaurus]] pijiagouensis''
|2=''Ikechosaurus sunailinae''
|3=''Tchoiria namsari''
|4=''Tchoiria klauseni''
|label5='''''[[Champsosaurus]]'''''
|5={{clade
|1=''C. gigas''
|2=''C. albertensis''
}}
|label6=''[[Simoedosaurus]]''
|6={{clade
|1=''S. lemoinei''
|2=''S. dakotensis''
}}
}}
|label2="Allochoristodera"
|2={{clade
|1=''[[Monjurosuchus]] splendens''
|2=''[[Philydrosaurus]] proseilus''
|3={{clade
|label1=''[[Lazarussuchus]]''
|1={{clade
|1=''L. inexpectatus''
|2=''Lazarussuchus'' sp.
|3=''L. dvoraki''
}}
|2={{clade
|1=''[[Khurendukhosaurus]] orlovi''
|2=''[[Hyphalosaurus]]'' sp.
|3={{clade
|1=''[[Hyphalosaurus]] lingyuanensis''
|2=''[[Shokawa]] ikoi''
}} }} }} }} }} }} }}}}

== Sedimentology and Paleoecology ==
[[File:Gharial (Gavialis gangeticus) female captive specimen (20469771858).jpg|left|thumb|Tchoiria would hunt similarly to the modern day [[Gharial]]]]
The Khuren Dukh Formation has been sampled as containing mostly [[mudstone]] layers. This does not change till the upper parts of the formation, transitioning to [[shale]] and [[Mudrock|claystone]] layers.<ref>{{Cite journal |last=Nichols |first=Douglas J. |last2=Matsukawa |first2=Masaki |last3=Ito |first3=Makoto |date=2006-04 |title=Palynology and age of some Cretaceous nonmarine deposits in Mongolia and China |url=http://dx.doi.org/10.1016/j.cretres.2005.11.004 |journal=Cretaceous Research |volume=27 |issue=2 |pages=241–251 |doi=10.1016/j.cretres.2005.11.004 |issn=0195-6671}}</ref> This formation was first explored in the early 1970's as a part of the Joint Soviet-Mongolian expeditions and has been dated to [[Aptian]] in age by pollen and invertebrate fossils.<ref>{{Cite journal |last=Hicks |first=J.F. |last2=Brinkman |first2=D.L. |last3=Nichols |first3=D.J. |last4=Watabe |first4=M. |date=1999-12 |title=Paleomagnetic and palynologic analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia |url=http://dx.doi.org/10.1006/cres.1999.0188 |journal=Cretaceous Research |volume=20 |issue=6 |pages=829–850 |doi=10.1006/cres.1999.0188 |issn=0195-6671}}</ref> The scant plant fossils found nearby shows the environment to be a staple of the Cretaceous; a temperate and plant-covered ecosystem. Dragonfly fossils found have been interpreted as a sign of an extension of the late [[Jurassic]] thermal maximum.<ref>{{Cite journal |last=Krassilov |first=Valentin |last2=Vassilenko |first2=Dmitry |last3=Sokolova |first3=Alexandra |last4=Barinova |first4=Sophia |date=2017 |title=New Fossil Plant and Insect Records Bearing on
Cretaceous Climate of Western Gobi, Mongolia |journal=American Journal of Plant Biology |volume=2 |issue=2 |pages=43-48}}</ref>

''Tchoiria'' lived in a diverse ecosystem of other invertebrate and vertebrate taxa. The aquatic environment included but is not limited to [[Mollusca|mollusks]], [[Ostracod|Ostracods]], [[Osteichthyes|bony fish]], [[Turtle|turtles]], some crocodiles, and ''Tchoiria'' itself. The terrestrial environment matched many other in the Early Cretaceous. Many dinosaurs including [[Psittacosaurus]], [[Harpymimus]], and some unidentified [[Theropoda|theropods]]. They coexisted with some [[Pterosaur|pterosaurs]] and small [[Lizard|lizards]].<ref name=":3" /> It would prey on fish and turtles mostly and would be hunted by a few crocodiles and theropod dinosaurs. ''Tchoiria'' would be a relatively uncommon animal in its ecosystem, but this could be due to a [[sampling bias]] with the locality.<ref name=":3" />


==References==
==References==
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{{Eureptilia|S.}}
{{Eureptilia|S.}}
{{Taxonbar|from=Q587956}}
{{Taxonbar|from=Q587956}}
[[Category:Aquatic reptiles]]

[[Category:Choristodera]]
[[Category:Choristodera]]
[[Category:Early Cretaceous reptiles of Asia]]
[[Category:Early Cretaceous reptiles of Asia]]
[[Category:Aquatic reptiles]]
[[Category:Paleontology in Mongolia]]
[[Category:Prehistoric reptile genera]]
[[Category:Prehistoric reptile genera]]



Revision as of 01:22, 3 March 2023

Tchoiria
Temporal range: Early Cretaceous (Aptian), 125–99.6 Ma
T. klauseni reconstruction
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Choristodera
Suborder: Neochoristodera
Genus: Tchoiria
Efimov, 1975
Species
  • T. namsari Efimov, 1975 (type)
  • T. klauseni Ksepka et al., 2005

Tchoiria (/ˈɔɪriə/) is a genus of neochoristoderan reptile from the Early Cretaceous of Mongolia. The name Tchoiria comes from the city of Choir which is nearby to where the holotype was found.[1] Tchoiria is thought to have a similar diet to another neochoristoderan reptile, Champsosaurus, due to morphology of the skull. It would hunt in freshwater environments, like the living gharials, where it would prey on many different types of fish and turtles.[2][3]

History of research

File:Tchoiria klauseni Skull.jpg
Dorsal view of the skull of T. klauseni

Tchoiria remains were first recovered as a part of the Joint Soviet-Mongolian Expeditions which took place in the Gobi Desert. They were described by Mikhail B. Efimov in 1975; basing his description on a partial cranium and some parts of the postaxial skeleton found at the Hühteeg Formation. He would make the type species T. namsari.[1][4] Efimov would name two other Tchoiria species in the latter 20th century, T. magnus in 1979 and T. egloni in 1983. Both taxa were based on postcranial fossils that were also found in the Hühteeg Formation. These would later be redescribed as new members of neochoristodera by Efimov.[5][4] The second valid species of Tchoiria would be named in 2005 by Danial T. Ksepka. T. klauseni would be based on a partial skull and some postcranial material found at the Two Volcanoes locality of southern Mongolia.[6] Efimov would place Tchoiria in the order choristodera in his original description.[1] Later it would also be placed in suborder neochoristodera in 2007 by Ryoko Matsumoto. Matsumoto would declare the suborder monophyletic in his paper on the choristodere Monjurosuchus.[7] Tchoiria was the first choristodere known from Asia and has been used in many morphological and environmental studies based on the order since its original description.[1][4]

Description:

Cranial

T. klauseni holotype from the Dinosaurios del desierto de Gobi exhibition in Chile

The skull of Tchoiria is similar to other neochoristoderes in having a flared postorbital region, an elongated and narrow snout, and having small orbits. The skull is also very flattened like other members of neochoristodera. The nasals have also fused into a single element. The teeth of Tchoiria are conical in shape and decrease in size further back in the skull. They also curve medially and have vertical, parallel lines. The orbits have a raised rim surrounding them and are very rough in texture.[6] Like other diapsid reptiles, Tchoiria has two temporal fenestrae behind the orbit. The snout is shorter than the Champsosaurus but still longer than other choristoderes. Other skull traits include a shortened lower jaw symphysis, a broader and shorter rostrum, and the posterior displacement of mandibular articulation.[1][4]

Postcranial

A complete set of vertebrae for Tchoiria have not been fully preserved but specimens of each section have been described. The vertebrae have amphiplatyan-style centrum and a closed notochordal canal. The dorsal vertebrae have small processes below their respective postzygapophyses. These are similar to the processes seen in both Simeodosaurus and Ikechosaurus.[6][8] The caudal vertebrae have the unique trait of having a deep groove bordered by ventral flanges; a trait seen in choristoderes but not usually in neochoristoderes. The caudal vertebrae also have unfused hemal arches. Tchoiria had similar gastralia to other members of its suborber. The limbs of Tchoiria are very fragmentary. Parts of the shoulder girdle are preserved and shows that they would be long and narrow. Besides a single femur, the rest of the hindlimbs are unknown.[6]

Species

Ikechosaurus, formerly T. egloni

There has been a total of four species of Tchoiria named, but as of 2023, only two are considered valid. T. magnus was moved to the genus Ikechosaurus in 1981 and T. egloni was moved to the new genus Irenosaurus in 1988.[4] These two taxa were moved due to morphological differences when compared to the T. namsari.

T. namsari is the type species and is known from the Hühteeg Formation of Mongolia. The other species, T. klauseni is known from the Two Volcanoes locality of southern Mongolia. T. klauseni was separated from T. namsari by the number of teeth in both the maxilla and the dentary. T. namsari is known to have more teeth, 60 in the maxilla and 17 in the symphyseal portion of the dentary, while T. klausnei has a smaller number of them, 34 in the maxilla and 12 in the symphyseal portion of the dentary.[6]

Classification

Tchoiria has been placed in neochoristodera, which is a clade within choristodera. The group first appeared in the Early Cretaceous of Asia and were successful due to the absence of crocodiles. Later in the Cretaceous and the early Paleocene, neochoristoderans needed to become more specialized because of their shared ecosystem with a wide range of crocodiles.[9]

An example of neochoristodera, Champsosaurus

The phylogenic tree below comes from Dong et al. (2020) shows neochoristodera and their relationship to other members of choristodera.[10]

Cteniogenys sp.

Heishanosaurus pygmaeus

Coeruleodraco jurassicus

Neochoristodera

Ikechosaurus pijiagouensis

Ikechosaurus sunailinae

Tchoiria namsari

Tchoiria klauseni

Champsosaurus

C. gigas

C. albertensis

Simoedosaurus

S. lemoinei

S. dakotensis

"Allochoristodera"

Monjurosuchus splendens

Philydrosaurus proseilus

Lazarussuchus

L. inexpectatus

Lazarussuchus sp.

L. dvoraki

Khurendukhosaurus orlovi

Hyphalosaurus sp.

Hyphalosaurus lingyuanensis

Shokawa ikoi

"

Sedimentology and Paleoecology

Tchoiria would hunt similarly to the modern day Gharial

The Khuren Dukh Formation has been sampled as containing mostly mudstone layers. This does not change till the upper parts of the formation, transitioning to shale and claystone layers.[11] This formation was first explored in the early 1970's as a part of the Joint Soviet-Mongolian expeditions and has been dated to Aptian in age by pollen and invertebrate fossils.[12] The scant plant fossils found nearby shows the environment to be a staple of the Cretaceous; a temperate and plant-covered ecosystem. Dragonfly fossils found have been interpreted as a sign of an extension of the late Jurassic thermal maximum.[13]

Tchoiria lived in a diverse ecosystem of other invertebrate and vertebrate taxa. The aquatic environment included but is not limited to mollusks, Ostracods, bony fish, turtles, some crocodiles, and Tchoiria itself. The terrestrial environment matched many other in the Early Cretaceous. Many dinosaurs including Psittacosaurus, Harpymimus, and some unidentified theropods. They coexisted with some pterosaurs and small lizards.[3] It would prey on fish and turtles mostly and would be hunted by a few crocodiles and theropod dinosaurs. Tchoiria would be a relatively uncommon animal in its ecosystem, but this could be due to a sampling bias with the locality.[3]

References

  1. ^ a b c d e Efimov, M.B. (1975). "Khampsozavrid iz Nizhnego Mela Mongolii". Iskopaemaya Fauna I Flora Mongolii. Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya, Trudy. 2: 84–93.
  2. ^ Evans, Susan E.; Hecht, Max K. (1993), Hecht, Max K.; MacIntyre, Ross J.; Clegg, Michael T. (eds.), "A History of an Extinct Reptilian Clade, the Choristodera: Longevity, Lazarus-Taxa, and the Fossil Record", Evolutionary Biology, Boston, MA: Springer US, pp. 323–338, doi:10.1007/978-1-4615-2878-4_8, ISBN 978-1-4615-2878-4, retrieved 2023-03-02
  3. ^ a b c Masaki., Matsukawa,. Early Cretaceous terrestrial ecosystems in East Asia based on food-web and energy-flow models. OCLC 1039765867.{{cite book}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  4. ^ a b c d e The age of dinosaurs in Russia and Mongolia. M. J. Benton. Cambridge: Cambridge University Press. 2003. ISBN 0-521-54582-X. OCLC 53710242.{{cite book}}: CS1 maint: others (link)
  5. ^ "Tchoiria". Paleobiology Database.
  6. ^ a b c d e Kspeka, D.T.; Evans, S.E.; Norell, M.A. (2005). "A New Choristodere from the Cretaceous of Mongolia". American Museum Novitates. 3468 (1).
  7. ^ Ryoko., Matsumoto, (2007). The choristoderan reptile Monjurosuchus from the Early Cretaceous of Japan. OCLC 999165005.{{cite book}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  8. ^ Evans, Susan E.; Manabe, Makoto (1999). "A choristoderan reptile from the Lower Cretaceous of Japan". Special papers in Palaeontology.
  9. ^ Matsumoto, R.; Evans, S. E. (2010). "Choristoderes and the freshwater assemblages of Laurasia". Journal of Iberian Geology. 36 (2): 253–274. doi:10.5209/rev_JIGE.2010.v36.n2.11. ISSN 1698-6180.
  10. ^ Dong, Liping; Matsumoto, Ryoko; Kusuhashi, Nao; Wang, Yuanqing; Wang, Yuan; Evans, Susan E. (2020-08-02). "A new choristodere (Reptilia: Choristodera) from an Aptian–Albian coal deposit in China". Journal of Systematic Palaeontology. 18 (15): 1223–1242. doi:10.1080/14772019.2020.1749147. ISSN 1477-2019.
  11. ^ Nichols, Douglas J.; Matsukawa, Masaki; Ito, Makoto (2006-04). "Palynology and age of some Cretaceous nonmarine deposits in Mongolia and China". Cretaceous Research. 27 (2): 241–251. doi:10.1016/j.cretres.2005.11.004. ISSN 0195-6671. {{cite journal}}: Check date values in: |date= (help)
  12. ^ Hicks, J.F.; Brinkman, D.L.; Nichols, D.J.; Watabe, M. (1999-12). "Paleomagnetic and palynologic analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia". Cretaceous Research. 20 (6): 829–850. doi:10.1006/cres.1999.0188. ISSN 0195-6671. {{cite journal}}: Check date values in: |date= (help)
  13. ^ Krassilov, Valentin; Vassilenko, Dmitry; Sokolova, Alexandra; Barinova, Sophia (2017). "New Fossil Plant and Insect Records Bearing on Cretaceous Climate of Western Gobi, Mongolia". American Journal of Plant Biology. 2 (2): 43–48. {{cite journal}}: line feed character in |title= at position 48 (help)