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...

Full description

Bibliographic Details
Main Authors: Kohta Kubo, Yoshitsugu Kobayashi, Tsogtbaatar Chinzorig, Khishigjav Tsogtbaatar
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2023-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0293801&type=printable
_version_ 1797394545701289984
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
format Article
id doaj.art-6f056881577448c7a77106f841b58d38
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)
record_format Article
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
work_keys_str_mv AT kohtakubo anewalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT yoshitsugukobayashi anewalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT tsogtbaatarchinzorig anewalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT khishigjavtsogtbaatar anewalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT kohtakubo newalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT yoshitsugukobayashi newalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT tsogtbaatarchinzorig newalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs
AT khishigjavtsogtbaatar newalvarezsauriddinosaurtheropodaalvarezsauriafromtheuppercretaceousbaruungoyotformationofmongoliaprovidesinsightsforbirdlikesleepingbehaviorinnonaviandinosaurs