The appendicular osteology of the Early Jurassic theropod Piatnitzkysaurus floresi and its implications on the morphological disparity of non-coelurosaurian tetanurans DOI
Luciano A. Pradelli, Diego Pol, Martín D. Ezcurra

et al.

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 203(1)

Published: Dec. 28, 2024

Abstract Piatnitzkysaurus floresi is a theropod dinosaur from the Cañadón Asfalto Formation (Chubut Province, Argentina) and one of few Early Jurassic tetanurans known worldwide. This species two specimens plays key role in our understanding early evolution tetanuran theropods. Nevertheless, published information about its postcranium limited to original description 1980s drawings views. Here, we redescribe detail appendicular skeleton Piatnitzkaysaurus integrate new into phylogenetic morphological disparity analyses focused on non-coelurosaurian tetanurans. Our results agree with recent studies that place Piatnitzkysauridae (including Condorraptor, Marshosaurus, Piatnitzkysaurus, Xuanhanosaurus) as earliest diverging group Allosauroidea within monophyletic Carnosauria (Allosauroidea + Megalosauroidea). Morphological show occupy different morphospace Cretaceous species. Condorraptor are found occupied by Middle Northern Hemisphere, which indicates presence similar body plans for during Early–Middle The improves knowledge

Language: Английский

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 DOI Creative Commons
K. Kubo, Yoshitsugu Kobayashi, Tsogtbaatar Chinzorig

et al.

PLoS ONE, Journal Year: 2023, Volume and Issue: 18(11), P. e0293801 - e0293801

Published: Nov. 15, 2023

Alvarezsauria is a group of early-branching maniraptoran theropods that are distributed globally from the Late Jurassic to latest Cretaceous. Despite recent increases in fossil record this group, scarcity complete specimens still restricts interpreting their detailed anatomy, ecology, and evolution. Here, we report new taxon derived alvarezsaur, Jaculinykus yaruui gen. et sp. nov., Cretaceous Mongolia, which represents nearly articulated skeleton. Our phylogenetic analysis reveals belongs sub-clade Alvarezsauridae, Parvicursorinae, forms mononphyletic with Mononykus Shuvuuia. Its well-preserved manus has only two fingers, composed hypertrophied digit I greatly reduced II, implies an intermediate condition between tridactyl Shuvuuia monodactyl Linhenykus. This highlights previously unrecognized variation specialization alvarezsaurid manus. Notably, preserved posture specimen exhibits stereotypical avian-like sleeping position seen troodontids Mei Sinornithoides. Evidence behavior alvarezsaur suggests stereotypically avian postures synapomorphy, providing more evidence bird-like traits being broadly among ancestors.

Language: Английский

Citations

12
New information on Bonapartenykus (Alvarezsauridae: Theropoda) from the Allen Formation (middle Campanian-lower Maastrichtian) of Río Negro Province, Patagonia, Argentina clarifies the Patagonykinae body plan DOI Creative Commons
Jorge Gustavo Meso, Jonah N. Choiniere, Mattia A. Baiano

et al.

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(1), P. e0308366 - e0308366

Published: Jan. 30, 2025

Alvarezsauria is a group of morphologically distinctive, medium- to small-sized later-diverging coelurosaurian theropod dinosaurs, whose record ranges from the Late Jurassic Cretaceous. This clade had widespread distribution in Laurasia what now Europe, Asia, and North America, although there are also several Cretaceous taxa Gondwana Argentina that all belong family Alvarezsauridae. Although alvarezsaurid taxonomic diversity anatomical knowledge has expanded over last decade, internal phylogenetic relationships remain highly debated. In this contribution, we describe new material review previously reported specimens middle Campanian—lower Maastrichtian Allen Formation discovered at Salitral Ojo de Agua locality Río Negro province, Patagonia, Argentina. these were collected different times without precise original provenance information, here gathered X-ray diffraction data associated sediments suggests come same site stratigraphic level as holotype Bonapartenykus ultimus . Based on information morphological similarity considered specimens, tentatively refer them genus These newly referred add shed light body plan Patagonykinae by permitting more complete reconstruction neck, pectoral girdle, hindlimb, tail.

Language: Английский

Citations

0
First unambiguous record of pneumaticity in the axial skeleton of alvarezsaurians (Theropoda: Coelurosauria) DOI Creative Commons
Guillermo J. Windholz, Jorge Gustavo Meso, Matt Wedel

et al.

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(4), P. e0320121 - e0320121

Published: April 2, 2025

Bonapartenykus ultimus is an alvarezsaurid theropod from the Upper Cretaceous of Patagonia, Argentina. This species represented by holotype specimen and several referred specimens, many which have pneumatic structures. Pneumaticity involves invasion interior skeleton means air sac diverticula. Such occurs cortical openings (foramina) that communicate with internal spaces. Despite previous studies on structures in there are no focusing family Alvarezsauridae. Here we address this gap presenting first contribution features using both external skeletal anatomy as well computed tomographic images showing details. The specimens studied show axial B. was invaded structures, reaching middle section tail. Our study suggests pneumaticity among alvarezsaurids did not a linear evolutionary trajectory, but instead shows more random pattern variability. important step paves way for future to uncover extent its macroevolutionary implications.

Language: Английский

Citations

0
A digging theropod? Enigmatic ankylosed phalanges from the Upper Cretaceous of Uzbekistan DOI
Alexander O. Averianov

PalZ, Journal Year: 2025, Volume and Issue: unknown

Published: April 16, 2025

Language: Английский

Citations

0
Assessing the palaeobiology of Vespersaurus paranaensis (Theropoda, Noasauridae), Cretaceous, Bauru Basin – Brazil, using Finite Element Analysis DOI
Gabriel Gonzalez Barbosa, Max C. Langer,

Neurides de Oliveira Martins

et al.

Cretaceous Research, Journal Year: 2023, Volume and Issue: 150, P. 105594 - 105594

Published: May 27, 2023

Language: Английский

Citations

5
Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria DOI Creative Commons
Jorge Gustavo Meso, Diego Pol, Luis M. Chiappe

et al.

Cladistics, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 11, 2024

Some of the smallest examples dinosaurian body size are from alvarezsaurians, an enigmatic group maniraptoran coelurosaurians with a peculiar combination anatomical features unique among theropods. Despite large number alvarezsaurian species described worldwide and increased understanding this has provided, body-size macroevolution alvarezsaurians received little attention. Here we reconstruct analyse directional trends evolution through integrated analysis mass, ontogenetic age, morphological rate data enabled by comprehensively revised phylogeny. Our analyses identify four periods high (Bathonian-Callovian, Hauterivian-early Berriasian, early Cenomanian, late Cenomanian-Turonian) that link to key effects animal changes for first time, including novelty, structural reduction simplification, elevated homoplasy, behavioral associated miniaturization. In doing so, study provides holistic example miniaturization in Mesozoic vertebrate offers framework other detailed studies evolution, more disparate groups.

Language: Английский

Citations

1
Osteology, relationship, and feeding ecology of the theropod dinosaur Noasaurus leali, from the Late Cretaceous of North-Western Argentina DOI
Christophe Hendrickx, Mauricio A. Cerroni, Federico L. Agnolín

et al.

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 202(4)

Published: Dec. 1, 2024

Abstract Noasaurus leali is a small (~2 m) carnivorous theropod and the nominal genus of clade Noasauridae, one two radiations abelisauroid ceratosaurs predominantly present in Southern Hemisphere during Mesozoic. This eponymous from Maastrichtian Lecho Formation Salta, Argentina, known an incomplete skeleton which strongly curved manual ungual most peculiar element. We here provide for first time comprehensive description holotypic specimens Noasaurus, whose phylogenetic position was explored using three independent datamatrices on relationships. species diagnosed by several apomorphies such as dorsal ridge maxillary fossa, arched quadrate, cervical neural arch with anterior epipophyseal prongs, subtriangular flexor fossa delimited V-shaped ridge. Results analyses recovered closely related to Velocisaurus, Masiakasaurus, Laevisuchus, together form Late Cretaceous radiation small-bodied noasaurids restricted Hemisphere. The morphology lateral dentition unguals suggests that opportunistic carnivore feeding prey items possible piscivore gaffing fish its specialized hand claws.

Language: Английский

Citations

0
The appendicular osteology of the Early Jurassic theropod Piatnitzkysaurus floresi and its implications on the morphological disparity of non-coelurosaurian tetanurans DOI
Luciano A. Pradelli, Diego Pol, Martín D. Ezcurra

et al.

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 203(1)

Published: Dec. 28, 2024

Abstract Piatnitzkysaurus floresi is a theropod dinosaur from the Cañadón Asfalto Formation (Chubut Province, Argentina) and one of few Early Jurassic tetanurans known worldwide. This species two specimens plays key role in our understanding early evolution tetanuran theropods. Nevertheless, published information about its postcranium limited to original description 1980s drawings views. Here, we redescribe detail appendicular skeleton Piatnitzkaysaurus integrate new into phylogenetic morphological disparity analyses focused on non-coelurosaurian tetanurans. Our results agree with recent studies that place Piatnitzkysauridae (including Condorraptor, Marshosaurus, Piatnitzkysaurus, Xuanhanosaurus) as earliest diverging group Allosauroidea within monophyletic Carnosauria (Allosauroidea + Megalosauroidea). Morphological show occupy different morphospace Cretaceous species. Condorraptor are found occupied by Middle Northern Hemisphere, which indicates presence similar body plans for during Early–Middle The improves knowledge

Language: Английский

Citations

0