Evaluating extinct pseudosuchian body mass estimates using a femur volume‐based model

The Anatomical Record, Год журнала: 2024, Номер 308(2), С. 257 - 265

Опубликована: Апрель 18, 2024

Abstract The clade Pseudosuchia appeared 250 million years ago. exclusively semi‐aquatic Crocodylia, which includes crocodiles, alligators, caimans, and gharials is the only surviving subgroup. Investigating Crocodylia biology pivotal for inferring traits of extinct pseudosuchians. Alligator femur length widely used modeling pseudosuchian body mass, but regression influenced by sex captivity status, leading to potential accuracy problems. An alternative model results from correlation between alligator volume unaffected those covariates. Here, an volume‐based applied estimate masses non‐crocodylian pseudosuchians, encompassing goniopholids, dyrosaurs, notosuchians, thalattosuchians. For each, as predictor yields lower than does length. Morphological resemblances existing crocodylians support inference that goniopholids dyrosaurs were semi‐aquatic. Therefore, predicted should be reasonable, although larger obtained may reflect sensitivity or environmental factors. Fully terrestrial notosuchians had proportionately longer femora their sizes compared crocodylians, suggesting higher are overestimates. aquatic thalattosuchians, skeletally adapted buoyancy with reduced reliance on locomotion, pose challenges both models. this study advocate use predict particularly encourage further exploration volumetric models size predictors vertebrates.

Язык: Английский

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Biotic and abiotic factors and the phylogenetic structure of extinction in the evolution of Tethysuchia

Paleobiology, Год журнала: 2024, Номер 50(2), С. 285 - 307

Опубликована: Апрель 23, 2024

Abstract Crocodylomorpha is a large and diverse clade with long evolutionary history now restricted to modern crocodilians. Tethysuchia less-inclusive of semi-amphibious taxa that crossed two biological crises: the second Oceanic Anoxic Event (OAE 2) Cretaceous/Paleogene (K/Pg) crisis. Numerous studies have sought find driving factors explaining crocodylomorph evolution, producing contradictory conclusions. Studies included groups may be useful. Here, we study tethysuchian evolution using phylogenetically informed statistical analyses. First, tested phylogenetic structure extinction at OAE 2 K/Pg crises. We then used comparative methods test influence intrinsic (body size, snout proportion) extrinsic (temperature, paleolatitude) on diversity Finally, whether temperature influenced body size. conclude (1) was not random in regard phylogeny for crises; (2) while an important turnover follows 2, crisis followed by explosion tethysuchians, probably linked colonization emptied ecological niches; (3) tethysuchians lived warmer environments after crisis, possibly because both global warming latitudinal distribution shifts; (4) there significant change proportion crises, likely caused niche partitioning; (5) positive correlation between size temperature, longer growth season.

Язык: Английский

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Integrative paleophysiology of the metriorhynchoid Pelagosaurus typus (Pseudosuchia, Thalattosuchia)

The Anatomical Record, Год журнала: 2024, Номер 308(2), С. 394 - 411

Опубликована: Авг. 23, 2024

Paleophysiology is an emergent discipline. Organismic (integrative) approaches seem more appropriate than studies focusing on the variation of specific features because traits are tightly related in actual organisms. Here, we used such organismic approach (including lifestyle, thermometabolism, and hunting behavior) to understand paleobiology lower Jurassic (Toarcian) thalattosuchian metriorhynchoid Pelagosaurus typus. First, show that lifestyle (aquatic, amphibious, terrestrial) has effect femoral compactness profiles amniotes. The profile indicates it was with a foraging activity shallow marine environments (as suggested by presence salt glands) thermoregulatory basking behavior land osteoderms highly developed ornamentation). As for mass-independent resting metabolic rate relatively high compared sample extant ectothermic amniotes, but analysis vascular canal diameter inferences red blood cell size refute hypothesis suggesting incipient endothermy. Finally, inferred using two proxies. had maximum aerobic scope higher those measured almost motionless Iguana iguana, similar sit-and-wait predator Crocodylus porosus quantified active hunter Varanus gouldii. These results suggest may have involving slow sustained swimming or patient waiting waters, caught preys like gharials, fast sideways sweeping motions head.

Язык: Английский

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New data on the bone histology of Araripesuchus buitreraensis (Crocodylomorpha: Notosuchia) from the Late Cretaceous of Argentinean Patagonia

Historical Biology, Год журнала: 2024, Номер 37(2), С. 293 - 303

Опубликована: Янв. 10, 2024

Araripesuchus is a genus of Notosuchia from the Upper Cretaceous southern continents. A previous paleohistological study performed in individuals assigned to one South American species (Araripesuchus buitreraensis) has revealed, among other palaeobiological inferences, cyclical and slow growth dynamics. To increase knowledge about dynamics intraskeletal interspecific histological variation, here we analyse microstructure femur, tibia, fibula, metatarsal (II, III IV) two osteoderms an individual referred cf.buitreraensis (MPCA-Pv 263) Late Argentina. All elements present cortex formed by both parallel fibred lamellar bone tissues interrupted lines arrested (LAGs), revealing general rate annually interrupted. similar strategy been inferred for notosuchians, as Iberosuchus macrodon, but important variation regarding this parameter evident clade. Although tissue suggests that reached sexual maturity (i.e. increasing intrinsic fibre arrangement outer cortex), absence external fundamental system indicates somatic maturation not attained. MPCA-Pv 263 exhibit discrete layer WFB cortical whose origin still unambiguous.

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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Pseudosuchian thermometabolism: A review of the past two decades

The Anatomical Record, Год журнала: 2024, Номер 308(2), С. 315 - 341

Опубликована: Дек. 16, 2024

Abstract Pseudosuchia, one of the two main clades Archosauria, is today only represented by some 20 extant species, crocodilians, representing a fraction its extinct diversity. Extant crocodilians are ectotherms but present morphological and anatomical features usually associated with endothermy. In 2004, it was proposed that pseudosuchians were ancestrally endothermic observed in remains this lost legacy. This contribution has parts: first part covers years studies on subject, exploring evidence for loss endothermy before covering variety proxies used to infer thermophymetabolic regime pseudosuchians. second part, quantitative results these previous integrated into comprehensive ancestral state reconstruction discuss potential scenario evolution thermometabolism. Pseudosuchian would then have been close node Crocodylomorpha. The end‐Triassic mass extinction played role filter, leading survival ectothermic ones. difference Pseudosuchia compared those dinosaurs, their metabolism also considered. might different level than dinosaurian more expected clarify question.

Язык: Английский

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On the origins of endothermy in amniotes

iScience, Год журнала: 2024, Номер 27(4), С. 109375 - 109375

Опубликована: Март 2, 2024

Язык: Английский

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Life history and growth dynamics of a peirosaurid crocodylomorph (Mesoeucrocodylia; Notosuchia) from the Late Cretaceous of Argentina inferred from its bone histology

Journal of Anatomy, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

Abstract Notosuchia were a successful lineage of Crocodyliformes that achieved remarkable diversity during the Cretaceous Gondwana, particularly in South America. Although paleohistology has expanded our knowledge paleobiology notosuchians, several clades this remain poorly understood aspect. Here we help to address gap by conducting first histological analysis appendicular bones peirosaurid. To increase about growth dynamics and examine intraeskeletal interspecific variation, analyze microstructure tibia, fibula, phalanx, fragment ornamented element (possible osteoderm or skull bone) possible long bone an individual assigned Peirosauridae indet. (MAU‐Pv‐437). The peirosaurid studied here appears have reached sexual but not somatic maturity minimum age inferred from results lower estimated than osteoderms previous study on same individual. cortical MAU‐Pv 437 is formed vascularized parallel fibered bone/lamellar which indicates experienced moderate rate. This different what been observed for other notosuchians specimens, suggesting lack uniform pattern clade.

Язык: Английский

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On the inference of red blood cell size from fossils

The Anatomical Record, Год журнала: 2025, Номер unknown

Опубликована: Фев. 13, 2025

Язык: Английский

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Phylogenetic structure of the extinction and biotic factors explaining differential survival of terrestrial notosuchians at the Cretaceous–Palaeogene crisis

Palaeontology, Год журнала: 2023, Номер 66(1)

Опубликована: Янв. 1, 2023

Abstract Although the clade Crocodylomorpha is represented by few extant species (Crocodylia), it has a rich fossil record. Hundreds of species, adapted to terrestrial, semi‐aquatic and marine environments, have existed over more than 200 million years. Numerous studies attempted characterize factors driving diversification extinction events Crocodylomorpha, resulting in ambiguous even contradictory conclusions, which points need for phylogenetically temporally smaller‐scaled studies. Here, we focus on differential survival at Cretaceous–Palaeogene (K–Pg) crisis Notosuchia, diverse mostly terrestrial that achieved great diversity during Cretaceous. More precisely, tested effect body size palaeotemperatures notosuchian probability K–Pg as well diet evolution their size. We find Notosuchia showed an evolutionary trend towards larger sizes through time, associated with shift from omnivorous carnivorous diet. This may explain why sebecids were only notosuchians survive crisis. also corroborate conclusions previous detected Lagerstätten occurring Adamantina Formation (Upper Cretaceous, Brazil, Bauru Group). work confirms value finely‐scaled macroevolutionary understanding history complex group such Crocodylomorpha.

Язык: Английский

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