The Avian Acetabulum: Small Structure, but Rich with Illumination and Questions DOI Creative Commons
Alan Feduccia

Diversity, Journal Year: 2023, Volume and Issue: 16(1), P. 20 - 20

Published: Dec. 27, 2023

The idea that birds are maniraptoran theropod dinosaurs is now considered an evolutionary consensus. An “open” (i.e., completely or substantially perforate) acetabulum important synapomorphy verifying the bird–dinosaur nexus. Here, I present anatomical evidence from and its appurtenances, supracetabular crest antitrochanter, hip anatomy differs between birds. Given thin bone of acetabular walls varied tissue, both hard soft, in region especially lower part basin, it apparent many avian skeletons exhibit some loss soft tissue bone, perhaps related to changes gait, but also dramatic trend reduction associated with flight, more advanced crown taxa. Many basal early diverging neornithines tend have a nearly closed partially acetabula, thus rendering current terms “closed” acetabula inaccurate; they should be modified replaced. new presented here, relationship “dinosaurs” must re-evaluated.

Language: Английский

Homeotic and nonhomeotic patterns in the tetrapod vertebral formula DOI Creative Commons
Rory Cerbus, Ichiro Hiratani, Kyogo Kawaguchi

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(47)

Published: Nov. 11, 2024

Vertebrate development and phylogeny are intimately connected through the vertebral formula, numerical distribution of vertebrae along body axis into different categories such as neck chest. A key window this relationship is conserved

Language: Английский

Citations

0
A new Cretaceous bird from the Maastrichtian La Colonia Formation (Patagonia, Argentina) DOI
Carolina Acosta Hospitaleche, José P. O’Gorman, Karen M. Panzeri

et al.

Cretaceous Research, Journal Year: 2023, Volume and Issue: 150, P. 105595 - 105595

Published: June 2, 2023

Language: Английский

Citations

1
Taphonomic damage obfuscates interpretation of the retroarticular region of theAsteriornismandible DOI Creative Commons

Abi Crane,

Juan Benito, Albert Chen

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: June 14, 2023

Abstract Asteriornis maastrichtensis , from the latest Cretaceous of Belgium, is among oldest known crown bird fossils, and its three-dimensionally preserved skull provides most substantial insights into cranial morphology early birds to date. Phylogenetic analyses recovered as a total-group member Galloanserae (the clade uniting Galliformes Anseriformes. One important feature supporting this placement was enlargement retroarticular processes, which form elongate caudal extensions mandible in extant Galloanserae. Here, we reinterpret jaw illustrate that caudalmost portion mandibles are fact not preserved. Instead, extremities both left right mandibular rami extend surface fossil block containing holotype skull, where they have eroded away. The originally identified process mandible—which exhibits orientation strikingly similar processes certain galloanserans, including Palaeogene total-clade anseriforms Conflicto Nettapterornis— instead represents twisted caudally displaced medial process. Nonetheless, anatomical comparisons with taxa reveal unable exclude possibility exhibited robust comparable those In light reinterpreted mandible, update original character matrix used investigate phylogenetic relationships, our revised continue support position galloanseran, initially interpreted. We demonstrate additional morphological traits provide new data on nature distribution birds.

Language: Английский

Citations

1
The Avian Acetabulum: Small Structure, but Rich with Illumination and Questions DOI Creative Commons
Alan Feduccia

Diversity, Journal Year: 2023, Volume and Issue: 16(1), P. 20 - 20

Published: Dec. 27, 2023

The idea that birds are maniraptoran theropod dinosaurs is now considered an evolutionary consensus. An “open” (i.e., completely or substantially perforate) acetabulum important synapomorphy verifying the bird–dinosaur nexus. Here, I present anatomical evidence from and its appurtenances, supracetabular crest antitrochanter, hip anatomy differs between birds. Given thin bone of acetabular walls varied tissue, both hard soft, in region especially lower part basin, it apparent many avian skeletons exhibit some loss soft tissue bone, perhaps related to changes gait, but also dramatic trend reduction associated with flight, more advanced crown taxa. Many basal early diverging neornithines tend have a nearly closed partially acetabula, thus rendering current terms “closed” acetabula inaccurate; they should be modified replaced. new presented here, relationship “dinosaurs” must re-evaluated.

Language: Английский

Citations

0