Cranial functional specialisation for strength precedes morphological evolution in Oviraptorosauria

Communications Biology, Год журнала: 2024, Номер 7(1)

Опубликована: Апрель 10, 2024

Abstract Oviraptorosaurians were a theropod dinosaur group that reached high diversity in the Late Cretaceous. Within oviraptorosaurians, later diverging oviraptorids evolved distinctive crania which extensively pneumatised, short and tall, had robust toothless beak, interpreted as providing powerful bite for their herbivorous to omnivorous diet. The present study explores ability of oviraptorid resist large mechanical stresses compared with other theropods where this adaptation originated within oviraptorosaurians. Digital 3D cranial models constructed earliest oviraptorosaurian, Incisivosaurus gauthieri , three oviraptorids, Citipati osmolskae Conchoraptor gracilis Khaan mckennai . Finite element analyses indicate oviraptorosaurian stronger than those ( Erlikosaurus Ornithomimus ) more comparable large, carnivorous Allosaurus biomechanics align indicating an early establishment strengthened Oviraptorosauria, even before highly modified morphology. Bite modelling, using estimated muscle forces, suggests may have functioned closer structural safety limits. Low around beaks suggest convergently evolved, functionally distinct rhamphotheca, serving cropping/feeding tool rather stress reduction, when theropods.

Язык: Английский

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Preserved soft anatomy confirms shoulder-powered upstroke of early theropod flyers, reveals enhanced early pygostylian upstroke, and explains early sternum loss

Proceedings of the National Academy of Sciences, Год журнала: 2022, Номер 119(47)

Опубликована: Ноя. 14, 2022

Anatomy of the first flying feathered dinosaurs, modern birds and crocodylians, proposes an ancestral flight system divided between shoulder chest muscles, before upstroke muscles migrated beneath body. This featured dorsally positioned deltoids supracoracoideus controlling chest-bound pectoralis downstroke. Preserved soft anatomy is needed to contextualize origin system, but this has remained elusive. Here we reveal earliest theropod flyers preserved as residual skin chemistry covering body delimiting its margins. These data provide that independently validate system. The heavily constructed more weakly in early pygostylian Confuciusornis indicated by a profile, upstroke-enhanced stroke. Slender ventral profiles early-diverging Archaeopteryx Anchiornis suggest habitual use could not maintain sternum through bone functional adaptations. Increased wing-assisted terrestrial locomotion potentially accelerated loss higher breathing requirements. Lower expected downstroke requirements thermal soarer Sapeornis have driven adaption, possibly encouraged demands Confuciusornis-like upstroke. Both factors are supported slender profile. shoulder/chest insights into novel strokes loss, filling important gaps our understanding appearance flight.

Язык: Английский

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The efficacy of computed tomography scanning versus surface scanning in 3D finite element analysis

PeerJ, Год журнала: 2022, Номер 10, С. e13760 - e13760

Опубликована: Авг. 25, 2022

Finite element analysis (FEA) is a commonly used application in biomechanical studies of both extant and fossil taxa to assess stress strain solid structures such as bone. FEA can be performed on 3D that are generated using various methods, including computed tomography (CT) scans surface scans. While previous palaeobiological have CT scanned models models, little research has evaluated what degree FE results may vary when the same object compared. Surface do not preserve internal geometries structures, which typically preserved Here, we created from specimens (crania mandibles Nile crocodile, green sea turtle, monitor lizard) under identical loading parameters. It was found once solidified, they output distributions model deformations comparable their counterparts, though differing by notable magnitudes some cases, depending morphology specimen reconstruction applied. Despite similarities overall mechanical behaviour, differ exterior shape compared due inaccuracies occur during scanning reconstruction, resulting local differences distribution. Solid-fill generally lower stresses compact interiors, must accounted for use types

Язык: Английский

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A new subadult specimen of oviraptorid Yulong mini (Theropoda: Oviraptorosauria) from the Upper Cretaceous Qiupa Formation of Luanchuan, central China

Cretaceous Research, Год журнала: 2022, Номер 138, С. 105261 - 105261

Опубликована: Май 21, 2022

Язык: Английский

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Craniodental ecomorphology of the large Jurassic ichthyosaurian Temnodontosaurus

Journal of Anatomy, Год журнала: 2023, Номер 244(1), С. 22 - 41

Опубликована: Авг. 17, 2023

Abstract Marine amniotes have played many crucial roles in ocean ecosystems since the Triassic, including predation at highest trophic levels. One genus often placed into this guild is large Early Jurassic neoichthyosaurian Temnodontosaurus , only post‐Triassic ichthyosaurian known with teeth which bear a distinct cutting edge or carina. This taxonomically problematic currently composed of seven species show wide variety skull and tooth morphologies. Here we assess craniodental disparity using series functionally informative traits. We describe range morphologies detail, first examples serrated carinae ichthyosaurians. These consist false denticles created by interaction enamel ridgelets carinal keel, as well possible cryptic true visible scanning electron microscopy. also find evidence for heterodonty T. platyodon unicarinate mesial likely playing role prey capture labiolingually compressed, bicarinate distal involved processing. type appears to be convergent other marine early cetaceans. Overall, referred configurations allowing captured processed different ways – example, eurycephalus has deep snout relatively small specialised increased wound infliction grip‐and‐tear feeding, whereas more elongate yet robust larger may adapted grip‐and‐shear feeding. results suggest existence niche partitioning higher levels ichthyosaurians implications future work on taxonomy wastebasket genus, research ecology extinct megapredatory tetrapods.

Язык: Английский

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Transitional chelal digit patterns in saprophagous astigmatan mites

Experimental and Applied Acarology, Год журнала: 2024, Номер 92(4), С. 687 - 737

Опубликована: Апрель 15, 2024

Abstract Changes in the functional shape of astigmatan mite moveable digit profiles are examined to test if Tyrophagus putrescentiae (Acaridae) is a trophic intermediate between typical micro-saprophagous carpoglyphid ( Carpoglyphus lactis ) and common macro-saprophagous glycyphagid Glycyphagus domesticus ). Digit tip elongation these mites decoupled from basic physics optimising inertia. Investment basal ramus/coronoid process compared that for mastication length varies with feeding style. A differentiated ascending ramus indicated C. T. different reasons. Culturing affects relative investments . markedly style inferred carpoglyphid. The acarid does not have an pattern form other two species. Mastication surface complexity confirms be heterodontous. particularly variably formed species trophically. plausible evolutionary path gradation forms illustrated. strengthening resist bending under occlusive loads explored detail. Extensions analytical approach suggested confirm decoupling cheliceral chelal adaptations. Caution expressed when interpreting ordinations multidimensional data mites.

Язык: Английский

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Functional and Character Disparity Are Decoupled in Turtle Mandibles

Ecology and Evolution, Год журнала: 2024, Номер 14(11)

Опубликована: Ноя. 1, 2024

Turtles have high shape variation of their mandibles, likely reflecting adaptations to a broad variety food items and ingestion strategies. Here, we compare functional disparity measured by biomechanical proxies character discrete morphological characters. Functional disparities vary between clades ecological groups are thus decoupled. Comparisons with cranial also indicate decoupled patterns within the turtle skull. Exploration mandibular reveals that several configurations or state combinations can lead same feeding type (i.e., convergence) be achieved at low exhaustion (e.g., cryptodires). Dietary specialists show larger than generalists, but phylogenetically widespread generalist ecology leads signals in ecotype. Whereas generally shows phylogenetic signal, correspond dietary specializations, which may occur convergently across different groups. Despite this, individual measurements overlapping ranges ecogroups do not always conform expectations. Jaw opening closing advantages model trade-offs force transmission opening/closing speeds, turtles values try synthesize into "jaw types". Closing mechanical advantage retain levels anterior jaw end compared other pseudosuchians). This possibly explained as an evolutionary adaptation bite forces small head sizes.

Язык: Английский

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“Dragons” on the landscape: Modeling the abundance of large carnivorous dinosaurs of the Upper Jurassic Morrison Formation (USA) and the Upper Cretaceous Dinosaur Park Formation (Canada)

The Anatomical Record, Год журнала: 2022, Номер 306(7), С. 1669 - 1696

Опубликована: Июль 11, 2022

Abstract Counts of the number skeletal specimens “adult” megaherbivores and large theropods from Morrison Dinosaur Park formations—if not biased by taphonomic artifacts—suggest that big meat‐eaters were more abundant, relative to plant‐eaters, than one would expect on basis abundance carnivores herbivores in modern mammalian faunas. Models megaherbivore population density (number individuals per square kilometer) attempt take into account ecosystem productivity, size structure populations, individual energy requirements, when combined with values theropod/megaherbivore ratio, suggest may have been abundant landscape estimates extrapolated versus body mass relationship carnivores. meat production populations requirements herbivore productivity insufficient support associated theropods, unless production/biomass ratio was substantially higher, and/or theropod requirement markedly lower, expectations based mammals. Alternatively, or addition both these other factors, likely included dinosaurs as significant components their diet.

Язык: Английский

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Functional morphology of the Triassic apex predator Saurosuchus galilei (Pseudosuchia: Loricata) and convergence with a post‐Triassic theropod dinosaur

The Anatomical Record, Год журнала: 2023, Номер 307(3), С. 549 - 565

Опубликована: Авг. 16, 2023

Abstract Pseudosuchian archosaurs, reptiles more closely related to crocodylians than birds, exhibited high morphological diversity during the Triassic and are thus associated with hypotheses of ecological this time. One example involves basal loricatans which non‐crocodylomorph pseudosuchians traditionally known as “rauisuchians.” Their large size (5–8+ m long) similarities post‐Triassic theropod dinosaurs, including dorsoventrally deep skulls serrated dentitions, suggest were apex predators. However, hypothesis does not consider functional behaviors that can influence refined roles predators in their environment, for example, degree carcass utilization. Here, we apply finite element analysis a juvenile but three‐dimensionally well‐preserved cranium loricatan Saurosuchus galilei investigate its morphology compare stress distributions from Allosaurus fragilis assess degrees convergence between carnivores. We find similar magnitudes two study taxa under same simulations, indicating had somewhat strong skull some theropods. also weak bite an animal (1015–1885 N) is broadly equivalent force modern gharials ( Gavialis gangeticus ). infer potentially avoided tooth–bone interactions consumed softer parts carcasses, unlike theropods other loricatans. This deduced feeding mode increases highlights differences

Язык: Английский

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Morphological evolution and functional consequences of giantism in tyrannosauroid dinosaurs

iScience, Год журнала: 2024, Номер 27(9), С. 110679 - 110679

Опубликована: Авг. 5, 2024

Язык: Английский

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