Avialan-like brain morphology in Sinovenator (Troodontidae, Theropoda)

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

Published: Feb. 10, 2024

Many modifications to the skull and brain anatomy occurred along lineage encompassing non-avialan theropod dinosaurs modern birds. Anatomical changes endocranium include an enlarged endocranial cavity, relatively larger optic lobes that imply elevated visual acuity, proportionately smaller olfactory bulbs suggest reduced capacity. Here, we use micro-computed tomographic (μCT) imaging reconstruct its neuroanatomical features from exceptionally well-preserved of Sinovenator changii (Troodontidae, Theropoda). While overall morphology resembles typical other troodontids, also exhibits unique are similar paravian taxa non-maniraptoran theropods. Landmark-based geometric morphometric analysis on shape avialan points most closely resembling Archaeopteryx, thus indicating acquisition avialan-grade in troodontids wide existence such architecture Maniraptora.

Language: Английский

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Artificial intelligence in paleontology

Earth-Science Reviews, Journal Year: 2024, Volume and Issue: 252, P. 104765 - 104765

Published: April 2, 2024

The accumulation of large datasets and increasing data availability have led to the emergence data-driven paleontological studies, which reveal an unprecedented picture evolutionary history. However, fast-growing quantity complication modalities make processing laborious inconsistent, while also lacking clear benchmarks evaluate collection generation, performances different methods on similar tasks. Recently, artificial intelligence (AI) has become widely practiced across scientific disciplines, but not so much date in paleontology where traditionally manual workflows been more usual. In this study, we review >70 AI studies since 1980s, covering major tasks including micro- macrofossil classification, image segmentation, prediction. These feature a wide range techniques such as Knowledge-Based Systems (KBS), neural networks, transfer learning, many other machine learning automate variety research workflows. Here, discuss their methods, datasets, performance compare them with conventional studies. We attribute recent increase most lowering entry bar training deployment models rather than innovations fossil compilation methods. present recently developed implementations diffusion model content generation Large Language Models (LLMs) that may interface future. Even though yet significant part paleontologist's toolkit, successful implementation is growing shows promise for paradigm-transformative effects years come.

Language: Английский

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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

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

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Simple shell measurements do not consistently predict habitat in turtles: a reply to Lichtig and Lucas (2017)

Peer Community Journal, Journal Year: 2025, Volume and Issue: 5

Published: Jan. 2, 2025

Inferring palaeoecology for fossils is a key interest of palaeobiology. For groups with extant representatives, correlations aspects body shape ecology can provide important insights to understanding extinct members lineages. The origin and ancestral turtles debated various shell or limb proportions have been reported correlate habitat among turtles, such that they may be informative inferring the fossil including early shelled stem turtles. One recently described method proposes simple measurements effectively quantify doming plastron width differentiate classes in linear discriminant analysis, whereby aquatic low domed shells narrow plastra. respective study unorthodox predictions lifestyles turtle Proganochelys quenstedtii meiolaniform Meiolania platyceps, terrestrial habits Proterochersis robusta. Here, we show these published results are consequence questionable methodological choices as omission species data which do not conform preconceived shape-ecology association. When reversed, corrected, phylogenetic flexible analysis applied, cannot correctly predicted based on measurements. This invalidates well proposed palaeohabitats fossils.

Language: Английский

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Cursorial ecomorphology and temporal patterns in theropod dinosaur evolution during the mid-Cretaceous

Royal Society Open Science, Journal Year: 2025, Volume and Issue: 12(1)

Published: Jan. 1, 2025

Coelurosauria, including modern birds, represents a successful group of theropod dinosaurs that established high taxonomic diversity and significant morphological modifications. In the evolutionary history this group, specialized foot morphology, arctometatarsus, evolved independently in several lineages has been considered an adaptation for cursoriality. While its functional significance extensively studied, temporal pattern parallel evolution, as well origin influencing factors, remains largely unresolved. Here, we show evolution cursorial traits, arctometatarsus hind limb proportions. Our study reveals proportional elongation distal segments preceded ornithomimosaurs oviraptorosaurs. contrast, tyrannosauroids, alvarezsaurs troodontids, tibia metatarsals occurred with acquisition arctometatarsus. The further highlights presence phylogenetic constraint outside specialization is restricted to members group. Finally, our date estimation, based on compiled patterns, demonstrates these traits emerged during mid-Cretaceous (93–120 Ma), suggesting selection locomotor performance throughout interval.

Language: Английский

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Avian telencephalon and cerebellum volumes can be accurately estimated from digital brain endocasts

Biology Letters, Journal Year: 2025, Volume and Issue: 21(1)

Published: Jan. 1, 2025

For studies of the evolution vertebrate brain anatomy and potentially associated behaviours, reconstructions digital endocasts from computed tomography scans have revolutionized our capacity to collect neuroanatomical data. However, measurements must be validated as reflecting actual anatomy, which is difficult because collection soft tissue information through histology laborious time-consuming. In birds, reliability endocast volume proxies for two largest regions—the telencephalon cerebellum—remains despite their use proxies, e.g. cognitive performance or flight ability. We here dataset date, including 136 species 25 avian orders, compare surface area with volumes telencephalon, cerebellum whole-brain endocast. Using linear phylogenetically informed regression analyses, we demonstrate that surfaces are strongly correlated counterparts both absolute relative size. This provides empirical support using endocast-derived cerebellar telencephalic areas in existing future living extinct potential expand dinosaur—bird transition future.

Language: Английский

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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

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

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First unambiguous record of pneumaticity in the axial skeleton of alvarezsaurians (Theropoda: Coelurosauria)

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

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New tools suggest a middle Jurassic origin for mammalian endothermy

BioEssays, Journal Year: 2022, Volume and Issue: 44(4)

Published: Feb. 16, 2022

We suggest that mammalian endothermy was established amongst Middle Jurassic crown mammals, through reviewing state-of-the-art fossil and living mammal studies. This is considerably later than the prevailing paradigm, has important ramifications for causes, pattern, pace of physiological evolution synapsids. Most hypotheses argue selection either enhanced aerobic activity, or thermoregulation primary driver synapsid evolution, based on a range characters have been linked to endothermy. that, rather alternative being selective force entirety endothermic these evolved quite independently time, across family tree, principally as response shifting environmental pressures ecological opportunities. Our interpretations can be tested using closely proxies both factors, derived from study fossils Cretaceous mammaliaforms early mammals.

Language: Английский

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Simple shell measurements do not consistently predict habitat in turtles: a reply to Lichtig and Lucas (2017)

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

Published: March 28, 2024

Abstract Inferring palaeoecology for fossils is a key interest of palaeobiology. For groups with extant representatives, correlations aspects body shape ecology can provide important insights to understanding extinct members lineages. The origin and ancestral turtles debated various shell or limb proportions have been reported correlate habitat among turtles, such that they may be informative inferring the fossil including early shelled stem turtles. One recently described method proposes simple measurements effectively quantify doming plastron width differentiate classes in linear discriminant analysis, whereby aquatic low domed shells narrow plastra. respective study unorthodox predictions lifestyles turtle Proganochelys quenstedtii meiolaniform Meiolania platyceps , terrestrial habits Proterochersis robusta . Here, we show these published results are consequence questionable methodological choices as omission species data which do not conform preconceived shape-ecology association. When reversed, corrected, phylogenetic flexible analysis applied, cannot correctly predicted based on measurements. This invalidates well proposed palaeohabitats fossils.

Language: Английский

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