Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods

PeerJ, Journal Year: 2023, Volume and Issue: 11, P. e15139 - e15139

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra (≥60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines). This suite features has made interpretations this group’s diet ecology difficult determine due lack analogous taxa similar together. Many extant bird groups rostral elongation, which is associated several disparate ecologies diets ( e.g ., aerial insectivory, piscivory, terrestrial carnivory). Thus, presence elongation only somewhat refines trophic predictions clade. Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition. group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference. Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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The influence of soft tissue volume on estimates of skeletal pneumaticity: implications for fossil archosaurs

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 11, 2024

Abstract Air space proportion (ASP), the volume fraction in bone occupied by air, is frequently applied as a measure for quantifying extent of skeletal pneumaticity extant and fossil archosaurs. Nonetheless, ASP estimates rely on key assumption: that soft tissue mass within pneumatic bones negligible, an assumption has rarely been explicitly acknowledged or tested. Here, we provide first comparisons between estimated air (where internal cavity assumed to be completely air-filled) true (ASPt, where tissues present cavities fresh specimens are considered). Using birds model archosaurs exhibiting postcranial pneumaticity, find ASPt significantly lower than ASP, raising important consideration should investigations evolution bulk density extinct archosaurs, well volume-based archosaur body mass. We advocate difference studies seeking quantify avoid risk systematically overestimating composed air.

Language: Английский

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3D atlas of tinamou (Neornithes: Tinamidae) pectoral morphology: Implications for reconstructing the ancestral neornithine flight apparatus

Journal of Anatomy, Journal Year: 2023, Volume and Issue: 243(5), P. 729 - 757

Published: June 26, 2023

Palaeognathae, the extant avian clade comprising flightless ratites and flight-capable tinamous (Tinamidae), is sister group to all other living birds, recent phylogenetic studies illustrate that are phylogenetically nested within a paraphyletic assemblage of ratites. As only palaeognaths have retained ability fly, may provide key information on nature flight apparatus ancestral crown palaeognaths-and, in turn, birds-as well as insight into convergent modifications wing among ratite lineages. To reveal new about musculoskeletal anatomy facilitate development computational biomechanical models tinamou function, we generated three-dimensional model Andean (Nothoprocta pentlandii) using diffusible iodine-based contrast-enhanced computed tomography (diceCT). Origins insertions pectoral musculature N. pentlandii generally consistent with those volant birds specialized for burst flight, entire suite presumed neornithine muscles present exception biceps slip. The pectoralis supracoracoideus robust, similar condition burst-flying such many Galliformes. Contrary most Neognathae (the Palaeognathae), insertion pronator superficialis has greater distal extent than profundus, although anatomical observations broadly conditions observed neognaths. This work will help form basis future comparative system, implications reconstructing clarifying underlying origins flightlessness.

Language: Английский

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Variation in the sacrum of phytosaurs: New evidence from a partial skeleton of Machaeroprosopus mccauleyi

Journal of Anatomy, Journal Year: 2024, Volume and Issue: 244(6), P. 959 - 976

Published: Jan. 29, 2024

Abstract Phytosaurs are a group of Upper Triassic semi‐aquatic archosauriform reptiles. Their variable skull morphology forms the foundation our understanding their relationships and paleoecology, while only few studies have focused on demonstrating existence postcranial variation. The numbers vertebrae in sacrum thought to vary from two, plesiomorphic condition for archosauriforms, three, with addition sacralized dorsal (i.e., dorsosacral) vertebra. In this study, we demonstrate presence first caudal caudosacral) vertebra belonging Machaeroprosopus mccauleyi . We rule out taphonomic distortion or pathology as explanations inclusion element sacrum, suggesting instead that it occurred through modifications same developmental processes likely produced dorsosacral phytosaurs. Additionally, show is common phytosaur specimens Chinle Formation Dockum Group southwestern United States suggest may be widespread among sacral potentially aided adaptation larger body sizes more terrestrial lifestyles certain taxa.

Language: Английский

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A juvenile bird with possible crown-group affinities from a dinosaur-rich Cretaceous ecosystem in North America

BMC Ecology and Evolution, Journal Year: 2024, Volume and Issue: 24(1)

Published: Feb. 9, 2024

Abstract Background Living birds comprise the most speciose and anatomically diverse clade of flying vertebrates, but their poor early fossil record lack resolution around relationships major clades have greatly obscured extant avian origins. Results Here, I describe a Late Cretaceous bird from North America based on fragmentary skeleton that includes cranial material portions forelimb, hindlimb, foot is identified as juvenile bone surface texture. Several features unite this specimen with crown Aves, its status precludes recognition distinct taxon. The American provenance supports cosmopolitan distribution birds, clashes hypothesized southern hemisphere origins living demonstrates closest relatives coexisted non-avian dinosaurs independently converged skeletal anatomy, such alvarezsaurids dromaeosaurids. Conclusions By revealing ecological biogeographic context within or near clade, Lance Formation provides new insights into contingent nature survival through Cretaceous-Paleogene mass extinction subsequent diversity.

Language: Английский

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The dinosaurian femoral head experienced a morphogenetic shift from torsion to growth along the avian stem

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2022, Volume and Issue: 289(1984)

Published: Oct. 5, 2022

Significant evolutionary shifts in locomotor behaviour often involve comparatively subtle anatomical transitions. For dinosaurian and avian evolution, medial overhang of the proximal femur has been central to discussions. However, there is an apparent conflict with regard origin femoral head, neontological palaeontological data suggesting seemingly incongruent hypotheses. To reconcile this, we reconstructed history morphogenesis end from early archosaurs crown birds. Embryological comparison living (crocodylians birds) suggests acquisition greater head dinosaurs results additional growth medial-ward direction. On other hand, fossil record that this was acquired by torsion end, which projected a more rostral direction ancestrally. We inferring dinosaur initially torsion, then superseded mediad growth. Details forms support hypothesis, their biomechanical implications are congruent general consensus regarding broader morpho-functional evolution on stem.

Language: Английский

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Homeotic and non-homeotic patterns in the tetrapod vertebral formula

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 26, 2024

Abstract Vertebrae can be differentiated into five categories along the body axis in tetrapods, with its numerical distribution known as vertebral formula. The formula is a principal tool for connecting development and phylogeny [1]. This largely due to robust relationship conserved clusters of Hox genes [2], which exhibit expression boundaries coincident divisions [3–11]. One avenue variations thus through -mediated homeotic transformations, manifest relatively fixed sum adjacent counts. expectation borne out mammalian thoracolumbar count [12], but date, no similar patterns have been found. Here we conduct systematic search by generating large dataset complete formulae diverse range tetrapod species probing variance linear combinations vertebrae. We uncover additional patterns, also unexpected balances between distal vertebrae not comprehensible regionalization. pattern appears during progression from theropods birds, demonstrating phylogenetic importance. further show that several counts correlate posterior intergenic distances HoxB gene cluster. By creating database mathematically defining our work establishes quantitative approach comparative genomics morphology.

Language: Английский

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Remarkable insights into modern bird origins from the Maastrichtian type area (north-east Belgium, south-east Netherlands)

Netherlands Journal of Geosciences – Geologie en Mijnbouw, Journal Year: 2024, Volume and Issue: 103

Published: Jan. 1, 2024

Abstract For centuries, fossils from the Maastrichtian type locality and adjacent quarries have provided key evidence of vertebrate diversity during latest Cretaceous, yet until recently area had revealed no important insights into evolutionary history birds, one world’s most conspicuous groups extant tetrapods. With benefit high-resolution micro-CT scanning, two avian now been examined in detail, offering profound, complementary birds. The holotype specimens these new taxa, Janavis finalidens Benito, Kuo, Widrig, Jagt Field, 2022, Asteriornis maastrichtensis Chen, Ksepka, 2020, were originally collected late 1990s, but only investigated detail more than twenty years later. Collectively, provide some best worldwide regarding factors that influenced stem bird extinction crown survivorship through Cretaceous-Palaeogene transition, as well origins anatomical features birds such an extensively pneumatised postcranial skeleton, a kinetic palate, toothless beak. also provides scarce Cretaceous-aged divergence time calibration within group, while together, constitute documented co-occurrence non-neornithine avialans. Here, we review by discoveries stratotype, document undescribed newly discovered potentially attributable to Avialae first histological data for , illustrating its skeletal maturity at death.

Language: Английский

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A new gansuid bird (Avialae, Euornithes) from the Lower Cretaceous (Aptian) Jiufotang Formation of Jianchang, western Liaoning, China

Cretaceous Research, Journal Year: 2024, Volume and Issue: unknown, P. 106014 - 106014

Published: Sept. 1, 2024

Language: Английский

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Birds, Diversification of

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Language: Английский

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