Mechanistic phylodynamic models do not provide conclusive evidence that non-avian dinosaurs were in decline before their final extinction

Cambridge Prisms Extinction, Journal Year: 2024, Volume and Issue: 2

Published: Jan. 1, 2024

Abstract Phylodynamic models can be used to estimate diversification trajectories from time-calibrated phylogenies. Here we apply two such phylogenies of non-avian dinosaurs, a clade whose evolutionary history has been widely debated. Although some authors have suggested that the experienced decline in diversity, potentially starting millions years before end-Cretaceous mass extinction, others group remained highly diverse right up until Cretaceous-Paleogene (K-Pg) boundary. Our results show model assumptions, likely with respect incomplete sampling, large impact on whether dinosaurs appear long-term or not. The are also sensitive topology and branch lengths phylogeny used. Developing comprehensive sampling bias, building larger more accurate phylogenies, necessary steps for us determine dinosaur diversity was not extinction.

Language: Английский

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A reassessment of the historical fossil findings from Bahia State (Northeast Brazil) reveals a diversified dinosaur fauna in the Lower Cretaceous of South America

Historical Biology, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 42

Published: April 11, 2024

Supposed dinosaur remains were collected between 1859 and 1906 in the Lower Cretaceous Recôncavo Basin (Northeast Brazil). Since these materials remained undescribed, most considered lost. Recently, some of historical specimens rediscovered Natural History Museum London, providing an opportunity to revisit them after 160 years. The come from five different sites, corresponding Massacará (Berriasian-Barremian) Ilhas (Valanginian-Barremian) groups. Identified bones comprise mainly isolated vertebral centra ornithopods, sauropods, theropods. Appendicular include a theropod pedal phalanx, humerus, distal half left femur with elasmarian affinities. Despite their fragmentary nature, represent earliest discovered South America, enhancing our understanding faunas Northeast Brazil. assemblage resembles coeval units Brazil, such as Rio do Peixe Basin, where ornithopods coexist sauropods This study confirms presence ornithischian dinosaurs Brazil based on osteological evidence, expanding biogeographic temporal range before continental rifting America Africa. Additionally, findings reinforce fossiliferous potential deposits Bahia State, which have been underexplored since initial discoveries.

Language: Английский

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Climatic constraints on the biogeographic history of Mesozoic dinosaurs

Current Biology, Journal Year: 2021, Volume and Issue: 32(3), P. 570 - 585.e3

Published: Dec. 17, 2021

Language: Английский

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Quantifying the effects of exceptional fossil preservation on the global availability of phylogenetic data in deep time

PLoS ONE, Journal Year: 2024, Volume and Issue: 19(2), P. e0297637 - e0297637

Published: Feb. 14, 2024

Fossil deposits with exceptional preservation (“lagerstätten”) provide important details not typically preserved in the fossil record, such that they hold an outsized influence on our understanding of biodiversity and evolution. In particular, potential bias imparted by this so-called “lagerstätten effect” remains a critical, but underexplored aspect reconstructing evolutionary relationships. Here, we quantify amount phylogenetic information available global records 1,327 species non-avian theropod dinosaurs, Mesozoic birds, squamates (e.g., lizards, snakes, mosasaurs), then compare lagerstätten content taxon selection analyses to other fossil-bearing deposits. We find groups preserve high their record theropods) are less vulnerable leads disproportionate representation taxa from one geologic unit tree. Additionally, for each taxonomic group, comparable amounts deposits, even though corresponding morphological character datasets vary greatly. Finally, unexpectedly ancient sand dune Late Cretaceous Gobi Desert Mongolia China exert anomalously large squamate suggesting can be present units traditionally considered lagerstätten. These results offer phylogenetics-based lens through which examine effects biological patterns time space, invites further quantification rock record.

Language: Английский

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A Spanish saltasauroid titanosaur reveals Europe as a melting pot of endemic and immigrant sauropods in the Late Cretaceous

Communications Biology, Journal Year: 2024, Volume and Issue: 7(1)

Published: Sept. 4, 2024

Language: Английский

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New sauropod teeth from the Upper Jurassic of Portugal and their implications for sauropod dental evolution

Papers in Palaeontology, Journal Year: 2025, Volume and Issue: 11(1)

Published: Jan. 1, 2025

Abstract The Upper Jurassic of Portugal is well known for its dinosaurian fauna, which includes five sauropod species. Although only one these species preserves associated dental material, isolated teeth are commonly found in the units Portugal. morphological diversity Portuguese has already been described and attributed to four morphotypes. Here, we report an additional 24 heart‐shaped teeth, 9 spatulate 16 compressed chisel‐shaped 10 pencil‐shaped hitherto unstudied collection Museu da Lourinhã. All morphotypes clades from fossil record, based on morphology tooth slenderness. statistical tests show a clear relation between widely used Slenderness Index (SI) taxonomy, proves be necessary correctly interpret any usage SI as taxonomic tool. As such, when it comes attribute Turiasauria, Camarasauridae, Titanosauriformes indet., Flagellicaudata. A reassessment evolution shows general trend increasing slenderness all studied groups, disappearance broad‐crowned taxa with developed tooth‐to‐tooth occlusion by end Early Cretaceous. We suggest that this may correlated batteries ornithischians, were more efficient oral food processing.

Language: Английский

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A brief review of non-avian dinosaur biogeography: state-of-the-art and prospectus

Biology Letters, Journal Year: 2024, Volume and Issue: 20(10)

Published: Oct. 1, 2024

Dinosaurs potentially originated in the mid-palaeolatitudes of Gondwana 245–235 million years ago (Ma) and may have been restricted to cooler, humid areas by low-latitude arid zones until climatic amelioration made northern dispersals feasible ca 215 Ma. However, this scenario is challenged new Carnian Laurasian fossils evidence that even earliest dinosaurs had adaptations for conditions. After becoming globally distributed Early–Middle Jurassic (200–160 Ma), experienced vicariance driven Pangaean fragmentation. Regional extinctions trans-oceanic also played a role, formation ephemeral land connections meant older patterns were repeatedly overprinted younger ones, creating reticulate biogeographic history. Palaeoclimates shaped dispersal barriers corridors, including filters differential effects on different types dinosaurs. Dinosaurian research faces many challenges, not least which patchiness fossil record. fossils, extensive databasing improved analytical methods help distinguish signal from noise generate fresh perspectives. In future, developing techniques quantifying ameliorating sampling biases modelling capacities are likely be two key components our modern programme.

Language: Английский

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Topology-Based Three-Dimensional Reconstruction of Delicate Skeletal Fossil Remains and the Quantification of Their Taphonomic Deformation

Frontiers in Ecology and Evolution, Journal Year: 2022, Volume and Issue: 10

Published: March 24, 2022

Taphonomic and diagenetic processes inevitably distort the original skeletal morphology of fossil vertebrate remains. Key aspects palaeobiological datasets may be directly impacted by such morphological deformation, as taxonomic diagnoses phylogenetic hypotheses, interpretations shape orientation anatomical structures, assessments interspecific intraspecific variation. In order to overcome these ubiquitous challenges we present a novel reconstruction workflow combining retopology retrodeformation, allowing both symmetrically asymmetrically damaged areas fossils reconstructed. As case studies, idealised three-dimensional reconstructions sternum crownward stem-bird Ichthyornis dispar , cervical vertebrae diplodocid sauropod Galeamopus pabsti . Multiple sterna were combined into single, composite representation through superimposition alignment retopologised models, this was subsequently retrodeformed. The individually retrodeformed symmetrised. Our enabled us quantify deformation individual specimens with respect our reconstructions, characterise global local taphonomic deformation. can integrated geometric morphometric approaches enable quantitative comparisons among multiple specimens, well interpolation “mediotypes” serially homologous elements missing vertebrae, haemal arches, or ribs.

Language: Английский

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Reappraisal of sauropod dinosaur diversity in the Upper Cretaceous Winton Formation of Queensland, Australia, through 3D digitisation and description of new specimens

PeerJ, Journal Year: 2024, Volume and Issue: 12, P. e17180 - e17180

Published: April 9, 2024

Skeletal remains of sauropod dinosaurs have been known from Australia for over 100 years. Unfortunately, the classification majority these specimens to species level has historically impeded by their incompleteness. This begun change in last 15 years, primarily through discovery and description several partial skeletons Cenomanian-lower Turonian (lower Upper Cretaceous) Winton Formation central Queensland, with four erected date: Australotitan cooperensis, Diamantinasaurus matildae, Savannasaurus elliottorum, Wintonotitan wattsi. The first three appear form a clade (Diamantinasauria) early diverging titanosaurs (or close relatives titanosaurs), whereas wattsi is typically recovered as distantly related non-titanosaurian somphospondylan. Through use 3D scanning, we digitised numerous sauropods, facilitating enhanced comparison between type referred specimens, heretofore undescribed specimens. We present new anatomical information on holotype specimen describe pertaining twelve individuals. Firsthand observations digital analysis enabled previously proposed autapomorphic features all named be identified newly described some exhibiting putative autapomorphies more than one species, prompting reassessment taxonomic validity. Supported specimen-level phylogenetic analysis, suggest that cooperensis probably junior synonym but conservatively regard it herein an indeterminate diamantinasaurian, meaning fauna now comprises (rather four) valid diamantinasaurian species: wattsi, latter robustly supported member time. refer provide revised diagnoses, regarded synapomorphies. Our presented data critical reappraisal sauropods facilitates comprehensive understanding mid-Cretaceous palaeobiota Queensland.

Language: Английский

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Skeletal and soft tissue completeness of the acanthodian fossil record

Palaeontology, Journal Year: 2022, Volume and Issue: 65(4)

Published: July 1, 2022

Abstract Acanthodians are a poorly understood paraphyletic grade of extinct Palaeozoic fishes. They play an increasingly prominent role in our understanding vertebrate evolution as part the chondrichthyan stem‐group even though their evolutionary history is scarce. The limited preservation mostly cartilaginous skeleton largely results bias towards isolated remains such fin spines and scales. Here, we quantify quality acanthodian fossil record by using variation Skeletal Completeness Metric (SCM), approach that calculates how complete skeletons individuals compared to theoretical skeleton. A novel Soft Tissue (STCM) introduced estimate percentage soft body tissue preserved alternate measurement completeness. scores for >1600 specimens comprising >300 taxa obtained from museum collection visits literature surveys were assembled into database. Acanthodian completeness peaks Lower–Middle Devonian, Pennsylvanian, earliest Permian. There no correlation between taxonomic richness show significantly lower distribution than many tetrapod groups, but similarly low bats. Skeletons deposited freshwater more marine environments where sea level negatively correlates with observed Our assessment reveals only weak spatial biases influencing while environmental much higher. This quantified evaluation acanthodians provides foundation further assessments likely influence character absences morphological datasets on estimates early and, therefore, gnathostome evolution.

Language: Английский

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