Waiting for Chromeornis...
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Ben Creisler
Dec 5, 2025, 6:40:00 PM (2 days ago) Dec 5
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Ben Creisler
Jingmai O’Connor, Xiaoli Wang, Alexander Clark, Pei-Chen Kuo, Ryan Davila, Yan Wang, Xiaoting Zheng, and Zhonghe Zhou
A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths
https://phys.org/news/2025-12-fossil-bird-death.html
https://www.sciencealert.com/this-prehistoric-bird-choked-to-death-on-800-rocks-and-no-one-knows-why
Waiting for a new paper to drop in final form... News is out online and parts of the article are visible if you search for Chromeornis on the Palaeontologia Electronica website. Still no paper...
Chromeornis funkyi gen. et sp. nov. STM7-156.
Jingmai O’Connor, Xiaoli Wang, Alexander Clark, Pei-Chen Kuo, Ryan Davila, Yan Wang, Xiaoting Zheng, and Zhonghe Zhou
A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths
A specimen representing a new genus and species closely related to Longipteryx is described. Fossilized soft tissues visible through UV light reveal details of its musculature. It preserves a large mass of gastroliths in the esophagus of uncertain significance.
==
This fossil bird choked to death on rocks, and no one knows why
The new species, named after electro-funk band Chromeo, helps tell the larger story of why only one small group of dinosaurs survived extinction
The new species, named after electro-funk band Chromeo, helps tell the larger story of why only one small group of dinosaurs survived extinction
https://phys.org/news/2025-12-fossil-bird-death.html
https://www.sciencealert.com/this-prehistoric-bird-choked-to-death-on-800-rocks-and-no-one-knows-why
Ben Creisler
Dec 5, 2025, 9:13:14 PM (2 days ago) Dec 5
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Chromeornis funkyi gen. et sp. nov.
Jingmai O’Connor, Xiaoli Wang, Alexander Clark, Pei-Chen Kuo, Ryan Davila, Yan Wang, Xiaoting Zheng, and Zhonghe Zhou (2025)
A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths.
Palaeontologia Electronica 28(3): a56.
doi: https://doi.org/10.26879/1589
https://palaeo-electronica.org/content/2025/5712-longipterygid-enantiornithine-chromeornis
Free pdf:
https://palaeo-electronica.org/content/pdfs/1589.pdf
The Longipterygidae are a diverse group of small to medium sized enantiornithine birds with elongate rostra and distally restricted dentition known from the Early Cretaceous Jehol Lagerstätten. The largest taxon, Longipteryx, is known from dozens of specimens but comparatively little is known about small-bodied taxa, sometimes resolved in a subclade, the Longirostravinae. Here we describe a small longipterygid representing a new taxon, Chromeornis funkyi gen. et sp. nov., with a combination of features present in longirostravines and Longipteryx. Cladistic analysis indicates the new species is a member of the Longipteryginae, more closely related to Longipteryx than other longipterygids. The specimen preserves extensive soft tissue including traces of the eyes, skin, and feathers, as well as an unusual mass of gastroliths preserved appressed against the left lateral margin of the cervical vertebrae. Computed-tomography based comparison with the in situ gastric mill preserved in the sympatric ornithuromorphs Archaeorhynchus and Iteravis strongly suggests these gastroliths are not gizzard stones. The absence of a gastric mill in enantiornithines is consistent with pectoral girdle morphology that indicates limited flight capabilities in Early Cretaceous species suggesting ground take off, a necessity of collecting stones, was energetically costly compared to ornithuromorphs. Increases in body mass due to a large gastric mill may have further impeded volant locomotion resulting in a low cost-benefit tradeoff such that this structure was unlikely to evolve during early enantiornithine evolution.
===
A new small-bodied longipterygid (Aves: Enantiornithes) from the Aptian Jiufotang Formation preserving unusual gastroliths.
Palaeontologia Electronica 28(3): a56.
doi: https://doi.org/10.26879/1589
https://palaeo-electronica.org/content/2025/5712-longipterygid-enantiornithine-chromeornis
Free pdf:
https://palaeo-electronica.org/content/pdfs/1589.pdf
The Longipterygidae are a diverse group of small to medium sized enantiornithine birds with elongate rostra and distally restricted dentition known from the Early Cretaceous Jehol Lagerstätten. The largest taxon, Longipteryx, is known from dozens of specimens but comparatively little is known about small-bodied taxa, sometimes resolved in a subclade, the Longirostravinae. Here we describe a small longipterygid representing a new taxon, Chromeornis funkyi gen. et sp. nov., with a combination of features present in longirostravines and Longipteryx. Cladistic analysis indicates the new species is a member of the Longipteryginae, more closely related to Longipteryx than other longipterygids. The specimen preserves extensive soft tissue including traces of the eyes, skin, and feathers, as well as an unusual mass of gastroliths preserved appressed against the left lateral margin of the cervical vertebrae. Computed-tomography based comparison with the in situ gastric mill preserved in the sympatric ornithuromorphs Archaeorhynchus and Iteravis strongly suggests these gastroliths are not gizzard stones. The absence of a gastric mill in enantiornithines is consistent with pectoral girdle morphology that indicates limited flight capabilities in Early Cretaceous species suggesting ground take off, a necessity of collecting stones, was energetically costly compared to ornithuromorphs. Increases in body mass due to a large gastric mill may have further impeded volant locomotion resulting in a low cost-benefit tradeoff such that this structure was unlikely to evolve during early enantiornithine evolution.
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Michael Habib
Dec 6, 2025, 1:56:58 AM (yesterday) Dec 6
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Very cool paper and a fascinating specimen. That said, I do have a gripe with their cost-of-flight argument. I see this problem fairly often, so this is a plea to everyone here to please keep track of the difference between *efficient* and *effective*. Far too many papers use “efficiency” or references to “energetic costs” when they really mean some other performance variable.
The limited flight capabilities (if correct) would tend to limit the angle and acceleration of climb out after launch proper (which seems to be what they really mean by "take off" here). That doesn’t make the behavior more expensive, it makes it less effective. This still fits their overall conclusion - but for a somewhat different reason. The problem isn’t the energetics, it’s the risk of getting caught on the ground as a mostly arboreal animal. It’s not an energetic cost/benefit ratio at play, it’s a risk/reward ratio - the risk of being eaten is relatively high because the ability to get away rapidly is poor. This is an important distinction that is missed when discussing living animals, too. Aerial sprinters with exceptional burst launch capacity (things like quail) are not more energetically efficient at take off. Rather, they are more able to burn a lot of energy in a hurry to generate a ton of power and reach very large accelerations - they’re *effective*, not efficient.
Cheers,
—Mike H.
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The limited flight capabilities (if correct) would tend to limit the angle and acceleration of climb out after launch proper (which seems to be what they really mean by "take off" here). That doesn’t make the behavior more expensive, it makes it less effective. This still fits their overall conclusion - but for a somewhat different reason. The problem isn’t the energetics, it’s the risk of getting caught on the ground as a mostly arboreal animal. It’s not an energetic cost/benefit ratio at play, it’s a risk/reward ratio - the risk of being eaten is relatively high because the ability to get away rapidly is poor. This is an important distinction that is missed when discussing living animals, too. Aerial sprinters with exceptional burst launch capacity (things like quail) are not more energetically efficient at take off. Rather, they are more able to burn a lot of energy in a hurry to generate a ton of power and reach very large accelerations - they’re *effective*, not efficient.
Cheers,
—Mike H.
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