Macroevolutionary trends in theropod dinosaur feeding mechanics

Current Biology, Год журнала: 2021, Номер 32(3), С. 677 - 686.e3

Опубликована: Дек. 16, 2021

Язык: Английский

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Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology

Science, Год журнала: 2023, Номер 379(6639), С. 1348 - 1352

Опубликована: Март 31, 2023

Large theropod dinosaurs are often reconstructed with their marginal dentition exposed because of the enormous size teeth and phylogenetic association to crocodylians. We tested this hypothesis using a multiproxy approach. Regressions skull length tooth for range theropods extant varanid lizards confirm that complete coverage dinosaur extraoral tissues (gingiva labial scales) is both plausible consistent patterns observed in living ziphodont amniotes. Analyses dental histology from crocodylians dinosaurs, including Tyrannosaurus rex, further indicate most likely condition was tissue when mouth closed. This changes our perceptions about appearance oral configuration these iconic predators has broad implications interpretations other terrestrial animals large teeth.

Язык: Английский

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Exceptionally preserved stomach contents of a young tyrannosaurid reveal an ontogenetic dietary shift in an iconic extinct predator

Science Advances, Год журнала: 2023, Номер 9(49)

Опубликована: Дек. 8, 2023

Tyrannosaurids were large carnivorous dinosaurs that underwent major changes in skull robusticity and body proportions as they grew, suggesting occupied different ecological niches during their life span. Although adults commonly fed on dinosaurian megaherbivores, the diet of juvenile tyrannosaurids is largely unknown. Here, we describe a remarkable specimen Gorgosaurus libratus preserves articulated hindlimbs two yearling caenagnathid inside its abdominal cavity. The prey selectively dismembered consumed separate feeding events. This predator-prey association provides direct evidence an ontogenetic dietary shift tyrannosaurids. Juvenile individuals may have hunted small young until reached size when, to satisfy energy requirements, transitioned megaherbivores. both mesopredator apex predator roles span, factor been key evolutionary success.

Язык: Английский

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Estimation of maximum body size in fossil species: A case study using Tyrannosaurus rex

Ecology and Evolution, Год журнала: 2024, Номер 14(7)

Опубликована: Июль 1, 2024

Among extant species, the ability to sample extremes of body size-one most useful predictors an individual's ecology-is highly unlikely. This improbability is further exaggerated when sampling already incomplete fossil record. We quantify likelihood uppermost limits size in record using

Язык: Английский

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Prey size and ecological separation in spinosaurid theropods based on heterodonty and rostrum shape

The Anatomical Record, Год журнала: 2024, Номер unknown

Опубликована: Авг. 28, 2024

Members of the dinosaur clade Spinosauridae had numerous traits attributed to feeding in or around water, and their apparatus has often been considered analogous modern crocodylians. Here we quantify craniodental morphology compare it Crocodylia. We measured from spinosaurid crocodylian skeletal material area alveoli as a proxy for tooth size determine size-heterodonty. Geometric morphometrics were also conducted on crowns bearing regions skull. Spinosaurids overall relatively large alveoli, both they, crocodylians, isolated enlarged alveoli. Spinosaurines along caudal dentary that baryonychines lacked, which instead additional positions. Size-heterodonty was positively allometric, spinosaurids overlapped with generalist/macro-generalist crocodylians similar sizes. Spinosaurid crown shape morphologies certain slender-longirostrine yet lacked molariform distal typical most rostra mandibles deep undulating margins correlating local sizes, may indicate developmental constraint. particularly long concavity rosette anterior cranial teeth, corresponding bulbous rostral dentary. The well suited quickly striking creating punctures, but not cutting flesh durophagy. jaws interlocked secure prey move deeper into mouth. probably did little oral processing, spinosaurines could have processed vertebrates. Overall, there is no indication restricted fish small aquatic prey.

Язык: Английский

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Biomechanical analyses of pterygotid sea scorpion chelicerae uncover predatory specialisation within eurypterids

PeerJ, Год журнала: 2022, Номер 10, С. e14515 - e14515

Опубликована: Дек. 9, 2022

Eurypterids (sea scorpions) are extinct aquatic chelicerates. Within this group, members of Pterygotidae represent some the largest known marine arthropods. Representatives family all have hypertrophied, anteriorly-directed chelicerae and commonly considered Silurian Devonian apex predators. Despite a long history research interest in these appendages, pterygotids been subject to limited biomechanical investigation. Here, we present finite element analysis (FEA) models four different pterygotid chelicerae-those

Язык: Английский

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Mammal‐bearing gastric pellets potentially attributable to Troodonformosus at the Cretaceous Egg Mountain locality, Two Medicine Formation, Montana, USA

Palaeontology, Год журнала: 2021, Номер 64(5), С. 699 - 725

Опубликована: Июль 28, 2021

Abstract Fossil gastric pellets (regurgitalites) have distinct taphonomic characteristics that facilitate inferences of behavioural ecology in deep time, despite their rarity the fossil record. Using patterns both extant and small mammals from more recent geologic deposits as a guide, we assess taphonomy three unusual multi‐individual aggregates mammal skeletons palaeosols at Egg Mountain, dinosaur nesting locality Upper Cretaceous Two Medicine Formation, Montana, USA. One aggregate consists two individuals multituberculate Filikomys primaevus . This specimen is characterized by brecciated crania, articulated postcrania, an absence digestive markings, all suggestive non‐predatory origin. additional consist 3 11 individuals, respectively, primarily marsupialiform Alphadon halleyi High proportions crania indigestible elements (e.g. teeth), extensive disarticulation breakage, corrosion patterns, phosphatic ground mass are indicative regurgitalites align with features prey diurnal raptor pellets. We interpret these specimens oldest known mammal‐bearing regurgitalites. The discrepancy implies separation between mammalian taxa locality. Abundant shed teeth evidence favours non‐avian theropod Troodon formosus predator responsible for regurgitalites, congruent previous small‐bodied diet, manipulation during feeding, heightened metabolic processes, potential nocturnality this taxon.

Язык: Английский

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Biomechanical performance of the cranio‐mandibular complex of the small notosuchian Araripesuchus gomesii (Notosuchia, Uruguaysuchidae)

The Anatomical Record, Год журнала: 2021, Номер 305(10), С. 2695 - 2707

Опубликована: Июнь 15, 2021

Notosuchia is a clade of crocodyliforms that was highly successful and diverse in the Cretaceous Gondwana. Araripesuchus gomesii small notosuchian from Early Brazil belongs to Uruguaysuchidae, one subgroups notosuchians first radiated, during Aptian-Albian. Here we present finite element analysis A. based on model reconstructed CT scans performed using published bone properties for crocodiles. The adductor musculature their respective attachment areas were Extant Phylogenetic Bracket. Different functional scenarios tested applying an estimated 158 N bite force: unilateral bite, bilateral pullback, head-shake, head-twist. results obtained compared with those Alligator mississippiensis, its closest living relatives. In different simulations, skull lower jaws suffers more stress head-shake movement, followed by pullback bites focalized premaxillary region. contrast, head-twist smaller values. possess oreinirostral may provide greater overall resistance average, unlike has platyrostral less dorsoventral mechanical loads. Previous hypotheses considered as omnivorous coupled our results, size, likely limited force, suggest this taxon probably fed prey other trophic items could catch handle entirely mouth, such insects vertebrates.

Язык: Английский

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Ontogenetic dietary shifts in North American hadrosaurids (Dinosauria: Ornithischia)

Cretaceous Research, Год журнала: 2022, Номер 135, С. 105177 - 105177

Опубликована: Фев. 23, 2022

Ontogenetic niche shifts, the phenomenon whereby animals change their resource use with growth, were probably widespread in dinosaurs, but most studies of duck-billed dinosaur ontogeny have so far focused mainly on development cranial ornamentation. Here, we quantify allometry 13 ecomorphological variables skull and examine tooth microwear a sample North American hadrosaurids to better understand ecological functioning growth. Our results indicate that, consistent Jarman-Bell principle relating body size fibre intake feeding selectivity, juvenile relatively more selective than adult counterparts subsisted softer, low-growing browse cropped using lateral rotations neck. Chewing movements jaw did not differ greatly between growth stages. findings invite further investigation ontogenetic hadrosauromorphs broadly, possible role shifts structuring Late Cretaceous herbivore communities.

Язык: Английский

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First application of dental microwear texture analysis to infer theropod feeding ecology

Palaeontology, Год журнала: 2022, Номер 65(6)

Опубликована: Ноя. 1, 2022

Abstract Theropods were the dominating apex predators in most Jurassic and Cretaceous terrestrial ecosystems. Their feeding ecology has always been of great interest, new computational methods have yielded more detailed reconstructions differences theropod behaviour. Many approaches, however, rely on well‐preserved skulls. Dental microwear texture (DMT) analysis is potentially applicable to isolated teeth, here employed for first time investigate dietary theropods. In particular, we test whether tyrannosaurids show DMT associated with hard‐object than compared Allosaurus ; this would be a sign higher levels osteophagy, as often suggested. We find no significant difference complexity roughness enamel surfaces between tyrannosaurids, which conflicts inferences frequent osteophagic behaviour Tyrannosaurus other Orientation wear features reveals pronounced bi‐directional puncture‐and‐pull mode tyrannosaurids. Our results further indicate ontogenetic niche shift theropods crocodylians, based significantly larger height parameters juvenile might scavenging, resulting bone–tooth contact during feeding. Overall, found very similar extant large, broad‐snouted crocodylians shows similarity throughout Cretaceous.

Язык: Английский

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