A new troodontid dinosaur from China with avian-like sleeping posture
Abstract
Discovering evidence of behaviour in fossilized vertebrates is rare. Even rarer is evidence of behaviour in non-avialan dinosaurs that directly relates to stereotypical behaviour seen in extant birds (avians) and not previously predicted in non-avialan dinosaurs. Here we report the discovery of a new troodontid taxon from the Early Cretaceous Yixian Formation of western Liaoning, China. Numerous other three-dimensionally preserved vertebrate fossils have been recovered recently at this locality, including some specimens preserving behavioural information. The new troodontid preserves several features that have been implicated in avialan origins. Notably, the specimen is preserved in the stereotypical sleeping or resting posture found in extant Aves. Evidence of this behaviour outside of the crown group Aves further demonstrates that many bird features occurred early in dinosaurian evolution.
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The forelimb to hindlimb ratio of 0.58 in Hesperornithoides is seen in Mahakala, Mei, Tianyuraptor, Caihong, Zhenyuanlong, Austroraptor, and Halszkaraptor.
“as seen in Mahakala, Mei, Tianyuraptor, Caihong, Zhenyuanlong, Austroraptor, and Halszkaraptor”
From A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight (2019) · cites this paper as Xu & Norell, 2004
The hind legs of WYDICE-DML-001 are folded in a crouching or resting position, the head is turned to the side underneath the left manus, and the preserved mid-caudal series wraps around the torso, reminiscent of the sleeping posture preserved in Mei and Sinornithoides.
“The hind legs are folded in a crouching or resting position, the head is turned to the side underneath the left manus, and the preserved mid-caudal series wraps around the torso, reminiscent of the sleeping posture preserved in Mei and Sinornithoides”
From A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight (2019) · cites this paper as Xu & Norell, 2004
Previously, four troodontid species have been reported from the Lower Cretaceous Jehol Group: Mei long, Sinovenator changii, Sinusonasus magnodens and Jinfengopteryx elegans.
“Previously, four troodontid species have been reported from the Lower Cretaceous Jehol Group: Mei long10, Sinovenator changii9, Sinusonasus magnodens11 and Jinfengopteryx elegans13.”
From Mosaic evolution in an asymmetrically feathered troodontid dinosaur with transitional features (2017) · cites this paper as [10]
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“…body craniocaudal facing, as in the articulated specimens Early Cretaceous Liaoningvenator DNHM D3012 ( Shen et al., 2017 ), Mei IVPP V 12733 ( Xu & Norell, 2004 ), Jinfengopteryx CAGS-IG-04-080 ( Ji et al., 2005 ), Jianianhualong DLXH 1218 ( Xu, Qin & Palasiatica, 2017 ), as well as the Late…”
Influential
- Authors
- Xu, X., & Norell, M. A.
- Affiliations
- American Museum of Natural History (US)
- Corresponding author
- Xu, Xing
- Venue
- Nature
- Published
- 2004-10
- Volume
- 431
- Issue
- 7010
- Pages
- 838-841
- ISSN
- 0028-0836 (ISSN-L)
- 1476-4687
- OpenAlex
- W2007869884
- Cited by
- 257
- References
- 0
- Citations by year
- 2026: 8 · 2025: 7 · 2024: 11 · 2023: 4 · 2022: 7 · 2021: 15 · 2020: 25 · 2019: 11 · 2018: 15 · 2017: 12 · 2016: 15 · 2015: 17 · 2014: 12 · 2013: 11 · 2012: 13
- FWCI
- 8.40
- Type
- journal article
- Language
- en
- Open access
- closed
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Nature (publishedVersion)
- PubMed (publishedVersion)
- reroDoc Digital Library (submittedVersion)
- RePEc: Research Papers in Economics (submittedVersion)
- Topics
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Paleontology and Evolutionary Biology
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Fossil Insects in Amber
- Keywords
- Troodontidae, sleep position, resting posture, avian origin, Yixian Formation, Lower Cretaceous
- MeSH terms
- Animals, Birds, China, Fossils, Posture, Skeleton, Sleep, Dinosaurs
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