A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs.
Alvarezsauria is a group of early-branching maniraptoran theropods that are distributed globally from the Late Jurassic to the latest Cretaceous. Despite recent increases in the fossil record of this group, the scarcity of complete specimens still restricts interpreting their detailed anatomy, ecolo...
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Public Library of Science (PLoS)
2023-01-01
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author | Kohta Kubo Yoshitsugu Kobayashi Tsogtbaatar Chinzorig Khishigjav Tsogtbaatar |
author_facet | Kohta Kubo Yoshitsugu Kobayashi Tsogtbaatar Chinzorig Khishigjav Tsogtbaatar |
author_sort | Kohta Kubo |
collection | DOAJ |
description | Alvarezsauria is a group of early-branching maniraptoran theropods that are distributed globally from the Late Jurassic to the latest Cretaceous. Despite recent increases in the fossil record of this group, the scarcity of complete specimens still restricts interpreting their detailed anatomy, ecology, and evolution. Here, we report a new taxon of derived alvarezsaur, Jaculinykus yaruui gen. et sp. nov., from the Late Cretaceous of Mongolia, which represents a nearly complete and articulated skeleton. Our phylogenetic analysis reveals that Jaculinykus belongs to the sub-clade of Alvarezsauridae, Parvicursorinae, and forms a mononphyletic group with Mononykus and Shuvuuia. Its well-preserved manus has only two fingers, composed of a hypertrophied digit I and greatly reduced digit II, which implies an intermediate condition between the tridactyl manus of Shuvuuia and monodactyl manus of Linhenykus. This highlights a previously unrecognized variation in specialization of alvarezsaurid manus. Notably, the preserved posture of the specimen exhibits a stereotypical avian-like sleeping position seen in the troodontids Mei and Sinornithoides. Evidence of this behavior in the alvarezsaur Jaculinykus suggests that stereotypically avian sleeping postures are a maniraptoran synapomorphy, providing more evidence of bird-like traits being distributed broadly among avian ancestors. |
first_indexed | 2024-03-09T00:21:20Z |
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institution | Directory Open Access Journal |
issn | 1932-6203 |
language | English |
last_indexed | 2024-03-09T00:21:20Z |
publishDate | 2023-01-01 |
publisher | Public Library of Science (PLoS) |
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series | PLoS ONE |
spelling | doaj.art-6f056881577448c7a77106f841b58d382023-12-12T05:34:22ZengPublic Library of Science (PLoS)PLoS ONE1932-62032023-01-011811e029380110.1371/journal.pone.0293801A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs.Kohta KuboYoshitsugu KobayashiTsogtbaatar ChinzorigKhishigjav TsogtbaatarAlvarezsauria is a group of early-branching maniraptoran theropods that are distributed globally from the Late Jurassic to the latest Cretaceous. Despite recent increases in the fossil record of this group, the scarcity of complete specimens still restricts interpreting their detailed anatomy, ecology, and evolution. Here, we report a new taxon of derived alvarezsaur, Jaculinykus yaruui gen. et sp. nov., from the Late Cretaceous of Mongolia, which represents a nearly complete and articulated skeleton. Our phylogenetic analysis reveals that Jaculinykus belongs to the sub-clade of Alvarezsauridae, Parvicursorinae, and forms a mononphyletic group with Mononykus and Shuvuuia. Its well-preserved manus has only two fingers, composed of a hypertrophied digit I and greatly reduced digit II, which implies an intermediate condition between the tridactyl manus of Shuvuuia and monodactyl manus of Linhenykus. This highlights a previously unrecognized variation in specialization of alvarezsaurid manus. Notably, the preserved posture of the specimen exhibits a stereotypical avian-like sleeping position seen in the troodontids Mei and Sinornithoides. Evidence of this behavior in the alvarezsaur Jaculinykus suggests that stereotypically avian sleeping postures are a maniraptoran synapomorphy, providing more evidence of bird-like traits being distributed broadly among avian ancestors.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0293801&type=printable |
spellingShingle | Kohta Kubo Yoshitsugu Kobayashi Tsogtbaatar Chinzorig Khishigjav Tsogtbaatar A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. PLoS ONE |
title | A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. |
title_full | A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. |
title_fullStr | A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. |
title_full_unstemmed | A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. |
title_short | A new alvarezsaurid dinosaur (Theropoda, Alvarezsauria) from the Upper Cretaceous Baruungoyot Formation of Mongolia provides insights for bird-like sleeping behavior in non-avian dinosaurs. |
title_sort | new alvarezsaurid dinosaur theropoda alvarezsauria from the upper cretaceous baruungoyot formation of mongolia provides insights for bird like sleeping behavior in non avian dinosaurs |
url | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0293801&type=printable |
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