Science, Journal Year: 2022, Volume and Issue: 375(6578)
Published: Jan. 20, 2022
The analysis of dinosaur ecology hinges on the appropriate reconstruction and biodiversity. Benson et al. question data used in our subsequent interpretation results. We address these concerns show that their reanalysis is flawed. Indeed, when occurrences are filtered to include only valid taxa, revised dataset strengthens earlier conclusions.
Language: Английский
The Anatomical Record, Journal Year: 2023, Volume and Issue: 307(5), P. 1897 - 1917
Published: Sept. 29, 2023
Abstract Tyrannosaurus has been an exemplar organism in feeding biomechanical analyses. An adult could exert a bone‐splintering bite force, through expanded jaw muscles and robust skull teeth. While function of thoroughly studied, such analyses have yet to expand other tyrannosauroids, especially early‐diverging tyrannosauroids ( Dilong, Proceratosaurus , Yutyrannus ). In our analysis, we broadly assessed the cranial performance at varying body sizes. Our sample size included small Dilong ), medium‐sized Teratophoneus large Tarbosaurus, Daspletosaurus Gorgosaurus ) incorporation tyrannosaurines different ontogenetic stages (small juvenile Raptorex mid‐sized We used muscle force calculations finite element analysis comprehend tyrannosauroids. Scaled subtemporal fenestrae areas calculated forces show that broad‐skulled exhibited higher than similarly sized Gorgosaurus, The proceratosaurid lower stress most tyrannosaurids. This suggests structural adaptations tyrannosaurids maintained adequate safety factors greater but their crania did not notably decrease bone stress. Similarly, experienced similarly‐sized earlier consistent with adductor juveniles, no more predecessors. As tyrannosauroid increased, so too relative manifested even juveniles giant adults.
Language: Английский
Citations
5
Historical Biology, Journal Year: 2021, Volume and Issue: 34(11), P. 2230 - 2240
Published: Dec. 8, 2021
It has been argued that, throughout the Mesozoic, immature growth forms of megaherbivorous dinosaurs competitively excluded small herbivorous dinosaur species, leading to left-skewed species richness-body mass distributions their fossil assemblages. By corollary, where large and herbivores coexisted over a geologically significant period time, they must have exhibited niche partitioning. We use multivariate ecomorphological analysis Late Cretaceous ornithischian assemblage North America examine this prediction. Our results indicate good separation most, but not all, at body size, although more work is required demonstrate that these patterns were adaptive. Calculation browse profiles using corrected abundance data bracketed estimates energy requirements suggests megaherbivores – most particularly hadrosaurids outstripped coexisting in control resource base.
Language: Английский
Citations
11
Cretaceous Research, Journal Year: 2024, Volume and Issue: 163, P. 105957 - 105957
Published: June 29, 2024
Taxonomic diversity in the derived tyrannosaurine Daspletosaurus has been hypothesized to represent a variety of evolutionary patterns by different authors. The recent description D. wilsoni, third species this genus, was proposed support paraphyly and participation its within single anagenetic lineage terminating at base clade formed Tyrannosaurus other gigantic tyrannosaurines (Tarbosaurus, Zhuchengtyrannus). However, reanalysis including additional data challenged interpretation, instead recovering as monophyletic sister group closest relatives, characterized several cladogenetic events. Here we show that incorporating further correcting erroneous interpretations relevant anatomical features overturns result. Using novel phylogenetic analysis specimens, recover paraphyletic Daspletosaurus, with genus forming successive taxa Tyrannosaurus-line tyrannosaurines. This result facilitates an interpretation currently recognized representing lineage, agreement stratigraphic distribution specimens qualitative range morphological variation observable wilsoni.
Language: Английский
Citations
1
Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)
Published: July 25, 2024
Tyrannosaurids were the most derived group of Tyrannosauroidea and are characterized by having two body plans: gracile, long-snouted robust, deep-snouted skulls. Both groups lived sympatrically in central Asia. Here, we report a new tyrannosaurid, Asiatyrannus xui gen. et sp. nov., from Upper Cretaceous Ganzhou City, southeastern China, which has produced large-bodied Qianzhousaurus. Based on histological analysis, holotype is not somatically mature adult, but it already passed through rapid growth stages. small to medium-sized tyrannosaurine, with skull length 47.5 cm an estimated total 3.5-4 m; or around half size Qianzhousaurus other tyrannosaurines similar sympatric tyrannosaurid genera Maastrichtian China. differs that proportionally deeper snout, longer premaxilla, maxilla, dentary, cornual process lacrimal inflated without developing discrete horn. The different proportions sizes suggest likely had feeding strategies occupied ecological niches.
Language: Английский
Citations
1
PLoS ONE, Journal Year: 2022, Volume and Issue: 17(10), P. e0275240 - e0275240
Published: Oct. 12, 2022
Removal or protection from biostratinomic agents of decomposition, such as predators and scavengers, is widely seen a requirement for high-quality preservation soft tissues in the fossil record. In this context, extremely rapid burial an oft-cited mechanism shielding remains degradation, but not all fossils fit nicely into paradigm. Dinosaurian mummies particular seemingly require two mutually exclusive taphonomic processes to preserve under that framework: desiccation burial. Here we present recently prepared Edmontosaurus mummy reveals alternate fossilization pathway resistant (e.g., skin nails). While on specimen well-preserved three dimensions contains biomarkers, it deflated marked by first documented examples injuries consistent with carnivore activity dinosaurian tissue during perimortem interval. Incomplete scavenging carcass provided route gases, fluids, microbes associated decomposition escape, allowing more durable persist through weeks months required prior entombment fossilization. This actualistic observations explains why skin, while rare, commonly preserved than expected if extreme circumstances were its preservation. More broadly, our assumptions guide collection research, presence biomolecules demonstrably rapidly buried, mummy, suggests types evidence may be substantially common previously assumed.
Language: Английский
Citations
7
Journal of African Earth Sciences, Journal Year: 2022, Volume and Issue: 193, P. 104595 - 104595
Published: May 24, 2022
Among the footprints found in Imilchil (Central High Atlas, Morocco) are two large ichnites that we characterize as "colossal" to distinguish them from "giant" theropod usage of other authors. These discoveries add scarce record very footprints, and contribute knowledge spatial-temporal distribution such colossal footprints. We classify sites with dinosaur tracks by their geographic location age Temporal Geographical Circumscriptions (TGCs) lead separation nine TGCs containing tracks. analyzed total content described relate footprint populations size. This analysis, which extends Middle Jurassic Upper Cretaceous, distributes geographically a limited (non-random) way. As consequence above, hypothesze may be zonal possibly due latitude, climate or geographical barriers. localized different according geological period.
Language: Английский
Citations
5
The Anatomical Record, Journal Year: 2022, Volume and Issue: 306(7), P. 1669 - 1696
Published: July 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.
Language: Английский
Citations
5
Historical Biology, Journal Year: 2021, Volume and Issue: 34(7), P. 1137 - 1145
Published: Aug. 22, 2021
The morphology of the neurovascular canal in jaw has been analysed several fossil reptiles, including theropod dinosaurs. However, details dentary theropods have not fully elucidated. In this study, we described well-preserved Tyrannosaurus rex, using computed tomography techniques, and compared its distribution pattern with other dinosaurs extant crocodiles. results show that exhibits a rather complex branching amongst sampled dinosaurs, complexity is comparable to crocodilians. likely related high tactile sensitivity dentary, suggesting tip may played an essential role as sensitive sensor.
Language: Английский
Citations
7
Frontiers of Biogeography, Journal Year: 2021, Volume and Issue: 14(2)
Published: Dec. 17, 2021
Marshall et al. recently estimated population densities, range sizes, instant and cumulative total sizes for Tyrannosaurus rex with narrow ranges of uncertainly. I revisit the assumptions that led them to these conclusions show many parameters are associated much wider margins error than they estimated. Biogeographic estimates seem have been especially unrealistic, seriously hampering effort calculate level parameters. posit biogeographic ecological uncertainties make it extremely unlikely be able estimate long-extinct species.
Language: Английский
Citations
4
Vertebrate Anatomy Morphology Palaeontology, Journal Year: 2022, Volume and Issue: 10(1)
Published: Nov. 28, 2022
Tyrannosaurid dinosaurs were ecologically unique vertebrates as the sole clade of large terrestrial carnivores (adults >400 kg) in their continent-spanning habitats. Expanded ligaments between metatarsals, inferred by gross morphology attachment correlates, have been hypothesized to strengthened specialized arctometatarsus. We tested hypothesis ligament presence with scanning electron microscopy and histological thin sections putative sites a third metatarsal tyrannosaurid Gorgosaurus libratus, compared section from unspecialized metatarsals early theropod Coelophysis bauri. In metatarsal, Sharpey´s fibers rough, pitted surface textures consistent coalescence occur at expansive distal regions localized rugosities are ideally located for resisting torsional loading on foot. Sparser Sharpey’s expected locations other arctometatarsus-bearing coelurosaurs. contrast, lacked or rugosity sectioned location, acting definitive negative control identifying these features tyrannosaurids. With soft-tissue correlates confirmed entheses, we conclude that tyrannosaurids possessed distinctive specific attachments lacking carnivorous dinosaurs. Histological evidence extensive intermetatarsal is greater agility derived than earlier lineages theropods.
Language: Английский
Citations
3