Results 171 to 180 of about 179,335 (194)

Postcranial anatomy and osteohistology of an early prozostrodont cynodont from the Upper Triassic of Brazil

open access: yesThe Anatomical Record, EarlyView.
Abstract Prozostrodon brasiliensis, a probainognathian cynodont of the clade Prozostrodontia, is recognized as a key taxon for understanding the origin of Mammaliaformes and mammals. Despite detailed investigations of its cranial anatomy, the postcranial skeleton has received comparatively less attention.
Iasmim M. Michelotti   +4 more
wiley   +1 more source

Description of large, well‐preserved Enchodus specimens from the Bearpaw Formation of Alberta, Canada

open access: yesThe Anatomical Record, EarlyView.
Abstract Fishes of the genus Enchodus were abundant and cosmopolitan in the Late Cretaceous, but are primarily known from isolated remains in Canada. Four well‐preserved fish skulls were recovered in recent years from ammolite mines sampling the Bearpaw Formation of Southern Alberta, and are here referred to Enchodus petrosus Cope, 1874.
Luke E. Nelson   +2 more
wiley   +1 more source

Tracheal chambers as a key innovation for high‐frequency emission in bat echolocation

open access: yesThe Anatomical Record, EarlyView.
Abstract Key innovations are pivotal for biodiversity and facilitating evolutionary success, enabling organisms' adaptation to various ecological niches through the diversification of phenotypic traits. In mammals, notable adaptations include evolving hypsodonty for grazing on grasses and, for bats, evolving echolocation and wing acquisition.
Nicolas L. M. Brualla   +7 more
wiley   +1 more source

Three‐dimensional digital analysis of musteloid masticatory muscle architecture

open access: yesThe Anatomical Record, EarlyView.
Musteloids span an enormous breadth of dietary modes within a single superfamily. In this study, we utilize digital dissection techniques to reconstruct the internal 3D anatomy of muscles within the musteloid feeding apparatus, and explore how dietary specializations might alter the size, orientation, and curvature of fascicles therein.
Cassidy E. Davis   +6 more
wiley   +1 more source

Scaling and ecomorphology of lagomorph body shape and appendicular skeleton

open access: yesThe Anatomical Record, EarlyView.
Abstract Body shape is one of the most prominent features of phenotypic variation. Yet, mammalian body shapes are poorly quantified and the underlying components contributing to its diversity and its relationship to other skeletal components are rarely tested.
Nia Brice, Coby Huizenga, Chris J. Law
wiley   +1 more source

Variable grouping patterns in primates: A test of the better competitor hypothesis in male Verreaux's sifaka (Propithecus verreauxi)

open access: yesThe Anatomical Record, EarlyView.
Abstract Intraspecific variation in social organization (IVSO) within primate populations can arise due to male mating competition. Verreaux's sifaka (Propithecus verreauxi) populations exhibit both single‐male and multi‐male groups, providing an opportunity to examine the relationship between male competitive ability and social organization.
Lemeng Li   +2 more
wiley   +1 more source

Local variation in age‐related cortical expansion within and between cross‐sections of distal human long bones

open access: yesThe Anatomical Record, EarlyView.
Abstract Cortical bone expansion is an age‐related process where, through endosteal resorption and periosteal apposition, cross‐sectional diameter increases while cortical thickness decreases in long bone diaphyses. Local variation has been observed in this process between cross‐sectional locations, but few studies have examined directional variation ...
Gregory J. Wehrman   +4 more
wiley   +1 more source

Fascicle measurement methods do result in lengths that are significantly different

open access: yesThe Anatomical Record, EarlyView.
A recent comparison of the most prevalent methods for measuring fascicles, in situ measurement versus chemical digestion, concluded that the measurements are indistinguishable based on data from different conspecific individuals. However, our study of contralateral muscles of the same individuals shows that the methods clearly result in statistically ...
Katherine M. Clark   +5 more
wiley   +1 more source

Evaluating Bergmann's and Allen's rules in the long bones of the eastern gray squirrel

open access: yesThe Anatomical Record, EarlyView.
Abstract Ecogeographical rules predict variation in body size and appendage proportions across climatic gradients, yet intraspecific tests using long bones from wild populations remain limited among small mammals. This study tests the hypothesis that eastern gray squirrels (Sciurus carolinensis) conform to Bergmann's rule, that is, body size increases ...
Tyler Blake, Habiba Chirchir
wiley   +1 more source

Anatomy and variation in the paraphyletic Mosasaurus lemonnieri assemblage from the Craie phosphatée de ciply, Belgium

open access: yesThe Anatomical Record, EarlyView.
Abstract Nineteenth century excavations of the Ciply‐Malogne Phosphatic Chalk Formation in Hainaut, Belgium, yielded over 50 partial mosasaur skeletons, the majority of which were referred to the species Mosasaurus lemonnieri Dollo, 1889. In the years since, this taxon has experienced a complicated taxonomic history, and its exceptional hypodigm has ...
Henry S. Sharpe   +3 more
wiley   +1 more source

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