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Cited by 34Paleontology and Evolutionary BiologyEvolution and Paleontology StudiesFossil Insects in Amber

Exceptional dinosaur fossils reveal early origin of avian-style digestion

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Zheng, Xiaoting, Wang, Xiaoli, Sullivan, Corwin, Zhang, Xiaomei, Zhang, Fucheng, Wang, Yan, Li, Feng, Xu, Xing·2018·Scientific Reports
DOI 10.1038/s41598-018-32202-xPMC PMC6155034
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Abstract

Birds have a highly specialized and efficient digestive system, but when this system originated remains uncertain. Here we report six gastric pellets attributable to the recently discovered 160-million-year-old troodontid dinosaur Anchiornis, which is among the key taxa for understanding the transition to birds. The gastric pellets contain lightly acid-etched lizard bones or fish scales, and some are associated with Anchiornis skeletons or even situated within the oesophagus. Anchiornis is the earliest and most basal theropod known to have produced gastric pellets. In combination with other lines of evidence, the pellets suggest that a digestive system resembling that of modern birds was already present in basal members of the Paraves, a clade including troodontids, dromaeosaurids, and birds, and that the evolution of modern avian digestion may have been related to the appearance of aerial locomotion in this lineage.

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  • These differences may reflect the elevated energetic cost associated with the appearance of flight in Aves.

    “These differences may reflect the elevated energetic cost associated with the appearance of flight in Aves [85].”

    From The ecology of Archaeopteryx (2026) · cites this paper as [85]

  • Archaeopteryx preserves three feeding-related structures that are not observed in nonvolant theropods and two of which are currently only recognized in birds: a primitive bill-tip organ, oral papillae, and an ossified basihyal.

    “Archaeopteryx preserves three feeding related structures that are not observed in nonvolant theropods and two of which are currently only recognized in birds: a primitive bill-tip organ, oral papillae, and an ossified basihyal [85] (Fig.3).”

    From The ecology of Archaeopteryx (2026) · cites this paper as [85]

    The Results describe gastric pellets in Anchiornis, and the Discussion addresses digestive features in theropods; neither addresses the claimed structures in Archaeopteryx. Searches for “bill-tip organ,” “oral papillae,” and “ossified basihyal” found no supporting passage in our copy. The paper’s silence on these structures is not a contradiction. (LLM, conf=0.75)

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  • The bill-tip organ in Archaeopteryx and other toothed Mesozoic birds differs from that observed in living birds, and is considered an early morphotype representing an intermediate evolutionary step in the evolution of the modern bill-tip organ.

    “The bill-tip organ in Archaeopteryx and other toothed Mesozoic birds differs from that observed in living birds, and is considered an early morphotype representing an intermediate evolutionary step in the evolution of the modern bill-tip organ [85].”

    From The ecology of Archaeopteryx (2026) · cites this paper as [85]

    Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 unverifiable. Expand the claim to see per-atom verdicts.

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  • The Chicago specimen of Archaeopteryx preserves soft tissue traces along the medial margin of the left palatine, interpreted as remnants of choanal oral papillae.

    “This specimen also preserves soft tissue traces along the medial margin of the left palatine interpreted as remnants of choanal oral papillae [85] (Fig.3).”

    From The ecology of Archaeopteryx (2026) · cites this paper as [85]

    The Results describe Anchiornis specimens and their preserved gastric pellets, not the Chicago specimen of Archaeopteryx. Searches of our copy for the Chicago specimen, left palatine, soft-tissue traces, and choanal oral papillae found no passage addressing the claim. (LLM, conf=0.76)

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  • Anchiornis lacks a bill-tip organ, ossified basihyal, and potentially oral papillae.

    “It also lacks a bill-tip organ, ossified basihyal, and potentially oral papillae [85].”

    From The ecology of Archaeopteryx (2026) · cites this paper as [85]

    The Results describe Anchiornis specimens and gastric pellets, while the Discussion describes its diet, digestion, and relatively short snout; no page numbers are available in our copy. Searches for bill-tip organ, ossified basihyal, and oral papillae found no passage addressing whether Anchiornis had those structures. (LLM, conf=0.75)

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Cites

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Sorted by citations

Authors
Zheng, X., Wang, X., Sullivan, C., Zhang, X., Zhang, F., Wang, Y., Li, F., & Xu, X.
Affiliations
  • Linyi University (CN)
  • University of Alberta (CA)
  • Shandong Pingyi Tianyu Museum of Natural History (CN)
  • Chinese Academy of Sciences (CN)
Corresponding author
  • Wang, Xiaoli
  • Xu, Xing
ORCID
Venue
Scientific Reports
Publisher
Springer Science and Business Media LLC
Published
2018-09-21
Volume
8
Issue
1
Pages
14217-14217
ISSN
2045-2322 (ISSN-L)
DOI
10.1038/s41598-018-32202-x
PMC
PMC6155034
OpenAlex
W2890462859
Cited by
34
References
6
Citations by year
2026: 2 · 2025: 7 · 2024: 2 · 2023: 7 · 2022: 4 · 2021: 4 · 2020: 6 · 2019: 2
FWCI
2.21
Type
journal article
Language
en
Open access
Licence
Locations
  • Scientific Reports (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
  • University of Alberta
  • National Natural Science Foundation of China (41402017, 41120124002, 41472023, 41372014, 91514302, #41688103)
  • Natural Sciences and Engineering Research Council of Canada (RGPIN 2017 ?, Discovery Grant (RGPIN–2017–06246), 06246, rgpin-2017-06246)
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
troodontids, digestive system evolution, Paraves, theropod dinosaurs, dinosaur-bird transition, aerial locomotion, esophagus, fish scales
MeSH terms
Animals, Birds, Bone and Bones, Digestive System, Biological Evolution, Fishes, Fossils, Lizards, Phylogeny, Dinosaurs

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