Cranial and postcranial anatomy of a juvenile baurusuchid (Notosuchia, Crocodylomorpha) and the taxonomical implications of ontogeny

The Anatomical Record, Год журнала: 2024, Номер unknown

Опубликована: Март 1, 2024

Abstract Baurusuchidae comprises a clade of top‐tier terrestrial predators and are among the most abundant crocodyliforms found in Adamantina Formation, Bauru Basin, Brazil (Campanian‐Maastrichtian). Here, we provide detailed description cranial postcranial osteology myology complete juvenile baurusuchid to date. Although preservation individuals is somewhat rare, previously reported occurrences egg clutches, yearling individual, larger, but skeletally immature specimens, comprise unique opportunity track anatomical changes throughout their ontogenetic series. Its anatomy was resolved with aid three‐dimensional model generated by acquisition computed tomography data, its inferred adductor mandibular musculature compared that mature specimens order assess possible shifts. A subsequent phylogenetic analysis included scoring Gondwanasuchus scabrosus , smallest species known date, evaluate relations relative juvenile. We find considerable differences between juveniles adults concerning skull ornamentation muscle development, which might indicate niche partitioning, also evidence G. corresponds young semaphoront lacking features.

Язык: Английский

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Determining whether a phosphatic concretion containing a Cretaceous juvenile crocodylian is a coprolite or a non-fecal concretion

Scientific Reports, Год журнала: 2025, Номер 15(1)

Опубликована: Фев. 22, 2025

Язык: Английский

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Ecomorphological patterns in trigeminal canal branching among sauropsids reveal sensory shift in suchians

Journal of Anatomy, Год журнала: 2023, Номер 242(5), С. 927 - 952

Опубликована: Янв. 20, 2023

The vertebrate trigeminal nerve is the primary mediator of somatosensory information from endings across face, extending branches through bony canals in face and mandibles, terminating sensory receptors. Reptiles evolved several extreme forms cranial somatosensation which enhanced tissues are present species engaging unique mechanosensory behaviors. However, morphology varies by clade ecology among reptiles. Few lineages approach degree tactile possessed crocodylians, only remaining members a that underwent an ecological transition terrestrial to semiaquatic habitat, also evolving specialized system. It remains be understood how osteological correlates inform adaptations for sensation crocodylians. Here we identify increase abilities Early Jurassic crocodylomorphs, preceding transitions habitat. Through quantification neurovascular canal branching patterns extant phylogenetic bracket quantify morphologies associated with behaviors representative fossil taxa, find stepwise progression increasing density, complexity, distribution primitive archosaurian derived crocodilian condition. Model-based inferences ecologies tested on quantified taxa known indicate parallel pseudosuchians. These findings establish reptile ecomorphology, revealing evolutionary ecology.

Язык: Английский

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A review of the non‐semiaquatic adaptations of extinct crocodylomorphs throughout their fossil record

The Anatomical Record, Год журнала: 2024, Номер 308(2), С. 266 - 314

Опубликована: Ноя. 25, 2024

Abstract Crocodylomorphs constitute a clade of archosaurs that have thrived since the Mesozoic until today and survived numerous major biological crises. Contrary to historic belief, their semiaquatic extant representatives (crocodylians) are not living fossils, and, during evolutionary history, crocodylomorphs evolved live in variety environments. This review aims summarize non‐semiaquatic adaptations (i.e., either terrestrial or fully aquatic) different groups from periods, highlighting how exactly those lifestyles inferred for animals, with regard geographic temporal distribution phylogenetic relationships. The ancestral condition Crocodylomorpha seems been lifestyle, linked several morphological such as an altirostral skull, long limbs allowing erect posture specialized dentition diets based on land. However, some members this clade, thalattosuchians dyrosaurids display opposite, aquatic interestingly same type observations. Finally, new techniques inferring paleobiology extinct animals put forward last decade, appearing complementary approach traditional descriptions comparisons. Such is case paleoneuroanatomical (CT scan data), histological, geochemical studies.

Язык: Английский

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New frontiers in imaging, anatomy, and mechanics of crocodylian jaw muscles

The Anatomical Record, Год журнала: 2022, Номер 305(10), С. 3016 - 3030

Опубликована: Июнь 20, 2022

New imaging and biomechanical approaches have heralded a renaissance in our understanding of crocodylian anatomy. Here, we review series the preparation, imaging, functional analysis jaw muscles crocodylians. Iodine-contrast microCT are enabling new insights into anatomy muscles, nerves, other soft tissues embryonic as well adult specimens alligators. These data muscle modeling methods offer increased accuracy sizes attachments without destructive like dissection. 3D together now enable us to see reconstruct architecture which then allows estimate resultants, but also measurements pennation ways not seen before. already revealed information on ontogeny, diversity, function heads alligators Such will lead enhanced accurate analyses form, function, evolution crocodylians, their fossil ancestors vertebrates general.

Язык: Английский

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Avian cranial kinesis is the result of increased encephalization during the origin of birds

Proceedings of the National Academy of Sciences, Год журнала: 2025, Номер 122(13)

Опубликована: Март 17, 2025

The origin of birds represents a pivotal transition in vertebrate evolution, marked by significant changes both brain size and feeding biomechanics. evolution the avian skull involved dramatic modifications, such as segmented palate development powered cranial kinesis neognath birds. Powered kinesis, ability to move parts independently, is considered key innovation behind dietary diversity evolutionary success However, processes driving emergence have remained unclear until recently. By analyzing data from Mesozoic birds, including reinterpretations homology, 3D jaw muscle biomechanics, linkage analysis, researchers quantified forces their effects on mechanics during theropods As neurocranium expanded non-avian theropods, temporal muscles shifted more rostrocaudal positions aiding segmentation pterygoid. This musculoskeletal transformation increased fore-aft force neognaths, enabling kinesis. A critical change was separation epipterygoid ossification braincase, leading breakdown primitive kinematic linkages new basicranial joint, which allowed for greater flexibility. These findings shed light how neurosensory systems coevolved bird origins offer methods identifying extinct vertebrates.

Язык: Английский

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A new specimen of the early branching crocodyliform Platyognathus hsui extends the record of gobiosuchids back 67 million years

Zoological Journal of the Linnean Society, Год журнала: 2025, Номер 204(2)

Опубликована: Июнь 1, 2025

Abstract Crocodyliforms are poorly known from the Early Jurassic Lufeng Formation of China, and a new specimen Platyognathus hsui is by far most complete yet known. It shares with missing holotype neotype very unusual features dentary caniniform that polygonal in cross-section fusion symphysis, provides four additional diagnosing species. Features such as relatively broad rostrum posteroventrolateral process on squamosal place it taxa closer to extant crocodylians than Orthosuchus Protosuchus, an early branching relative Gobiosuchidae. The oldest previous record gobiosuchid lineage was late Barremian stage Cretaceous, this extends fossil back 67 Myr. We recognize superfamily, Gobiosuchoidea, include gobiosuchids.

Язык: Английский

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Anatomically grounded estimation of hindlimb muscle sizes in Archosauria

Journal of Anatomy, Год журнала: 2022, Номер 242(2), С. 289 - 311

Опубликована: Окт. 7, 2022

Abstract In vertebrates, active movement is driven by muscle forces acting on bones, either directly or through tendinous insertions. There has been much debate over how size and force are reflected the muscular attachment areas (AAs). Here we investigate relationship between physiological cross‐sectional area (PCSA), a proxy for production of muscle, AA hindlimb muscles in Nile crocodiles five bird species. The limbs were held fixed position whilst blunt dissection was carried out to isolate individual muscles. AAs digitised using point digitiser, before removed from bone. Muscles then further dissected fibre architecture measured, PCSA calculated. raw measures, as well ratio AA, studied compared intra‐observer error intra‐ interspecies differences. We found large variations both within across species, but fascicle lengths conserved whether this tinamou. Whilst discriminant analysis able separate crocodylian avian data, ratios all species most can be represented single equation. remaining have specific equations represent their scaling, often relatively high success at predicting PCSA. Coelophysis bauri , dinosaur, estimate PCSAs therefore maximal isometric forces. results somewhat consistent with other methods estimating production, suggest that, least some archosaurian muscles, that it possible use sizes. This method complementary such digital volumetric modelling.

Язык: Английский

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Biomechanical analysis and new trophic hypothesis for Riojasuchus tenuisceps, a bizarre-snouted Late Triassic pseudosuchian from Argentina.

Acta Palaeontologica Polonica, Год журнала: 2023, Номер 68

Опубликована: Янв. 1, 2023

Ornithosuchids are a Late Triassic pseudosuchian archosaur group, consisting of four species (three from South America, and one Scotland).All them have triangular skulls with protruding premaxilla, large nostrils, an extensive diastema in their narrow snout, short jaw that does not reach the anterior end skull, serrated posteriorly curved teeth.For this clade, carnivorous scavenger habits been previously proposed.Within Ornithosuchidae, Riojasuchus tenuisceps (from Argentina) has most morphologically extreme characteristics.Based on CT scans preserved we generated 3D model, over this, estimated volumes adductors abductor muscles force exerted by each.From these data built finite element model measured bite (1.8-2.3 kN).Lateral, tractive, torsional forces were applied to snout evaluate structural response skull during feeding.The results show R. could resist tractive stresses better than lateral stress.Additionally, analysed peculiar morphological characteristics functional implications.We observed upper lower dental rows laterally separated each other, preventing generation cutting line occlusion, therefore, would fed small-sized prey it swallow whole.The premaxilla mandible allow tip (ruling out scavenging hypothesis), but instead more adequate capturing suspended fluid.This set allows us propose had zoophagous diet wading habit, being able feed fish, amphibians, or any small animals they catch shoreline.

Язык: Английский

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Anatomy and ontogeny of the “carnivorous aetosaur”: New information on Coahomasuchus kahleorum (Archosauria: Pseudosuchia) from the Upper Triassic Dockum Group of Texas

The Anatomical Record, Год журнала: 2024, Номер 308(2), С. 671 - 735

Опубликована: Ноя. 18, 2024

Abstract A newly referred specimen of Coahomasuchus kahleorum (TMM 31100‐437) from the lower part Upper Triassic Dockum Group Texas preserves much skeleton including majority skull. Introduced in literature 1980s as “carnivorous aetosaur”, TMM 31100‐437 bears recurved teeth that previously were considered unique among aetosaurs. The small size individual led to speculation it represents a skeletally immature retains plesiomorphic dentition for Archosauromorpha. We provide detailed evaluation anatomy and phylogenetic relationships this specimen. Apomorphies osteoderms braincase support referral C. . Histological analysis femur demonstrates does not represent juvenile form another known aetosaur. Thus, 31000‐437 provides case demonstrating aetosaur species spanned wide range maximum body sizes, approximately 1.5 m over 5 length. Reanalysis type , along with information 31000‐437, lateral are autapomorphic described have distinct medial flanges well dorsal eminence. Overall, key details regarding diet an early occurring

Язык: Английский

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