Results 51 to 60 of about 41,570 (260)

Breaking evolutionary and pleiotropic constraints in mammals: On sloths, manatees and homeotic mutations

open access: yesEvoDevo, 2011
Background Mammals as a rule have seven cervical vertebrae, except for sloths and manatees. Bateson proposed that the change in the number of cervical vertebrae in sloths is due to homeotic transformations. A recent hypothesis proposes that the number of
Varela-Lasheras Irma   +5 more
doaj   +1 more source

Histovariability and fossil diagenesis of Pissarrachampsa (Pseudosuchia, Notosuchia, Baurusuchidae) from the Upper Cretaceous of Southeast Brazil

open access: yesThe Anatomical Record, EarlyView.
Abstract Notosuchians were key components of western Gondwanan Cretaceous ecosystems in terrestrial predator niches and exhibited remarkable taxonomic and ecological diversity. Previous research has explored their physiology, metabolism, and histology, revealing varied growth patterns and life history strategies.
Tito Aureliano   +5 more
wiley   +1 more source

Anatomo-radiographic description of the axial skeleton of the crab-eating fox (Cerdocyon thous)

open access: yesPesquisa Veterinária Brasileira, 2012
The aim of this study was to describe the axial skeleton of a wild Brazilian carnivorous, the crab-eating fox (Cerdocyon thous). Five specimens of crab-eating fox were previously unfrozen for radiographic exams and their bones went through dissection and
Janaína D. Barisson   +5 more
doaj   +1 more source

Inside a duck‐billed dinosaur: Vertebral bone microstructure of Huallasaurus (Hadrosauridae), Upper Cretaceous of Patagonia

open access: yesThe Anatomical Record, EarlyView.
Abstract Dinosaurs evolved a unique respiratory system with air sacs that contributed to their evolutionary success. Postcranial skeletal pneumaticity (PSP) has been used to infer the presence of air sac systems in some fossil archosaurs. While unambiguous evidence of PSP is well documented in pterosaurs and post‐Carnian saurischians, it remains absent
Tito Aureliano   +3 more
wiley   +1 more source

Congenital fusion of cervical vertebrae: a review on embryological etiology [PDF]

open access: yesReviews in Clinical Medicine, 2016
Congenital fusion of cervical vertebrae is a rare anomaly. In this condition, two fused vertebrae appear structurally and functionally as one. This anomaly may be symptomatic or asymptomatic.
Mohammad Mardani   +2 more
doaj   +1 more source

A contribution to the anatomy of two rare cetacean species: The hourglass dolphin (Cephalorhynchus cruciger) and the spectacled porpoise (Phocoena dioptrica)

open access: yesThe Anatomical Record, EarlyView.
Abstract The anatomical description of the hourglass dolphin (Cephalorhynchus cruciger) and the spectacled porpoise (Phocoena dioptrica) remains largely unexplored, due to limited specimen availability and preservation challenges. This study employed digital imaging techniques, conventional histology, and computed tomography to provide visualization of
Jean‐Marie Graïc   +26 more
wiley   +1 more source

Early Pliocene Varanus (Squamata, Varanidae) remains from Megalo Emvolon, Thessaloniki, Greece

open access: yesThe Anatomical Record, EarlyView.
The article describes new cranial and postcranial varanid material from Megalo Emvolon Lower Pliocene vertebrate fossil site near Thessaloniki. The fossils, likely representing a single individual, are referred to Varanus cf. marathonensis. Abstract This study describes new fossil varanid material from a recently discovered fossil spot (MVL site) at ...
Chara Drakopoulou   +3 more
wiley   +1 more source

The research on safe range of the anterior transpedicular screw in lower cervical vertebrae [PDF]

open access: green, 2022
Sen-qi Ye   +5 more
openalex   +1 more source

Osteological correlates of the respiratory and vascular systems in the neural canals of Mesozoic ornithurines Ichthyornis and Janavis

open access: yesThe Anatomical Record, EarlyView.
Abstract In birds, the neural canal houses a variety of anatomical structures including the spinal cord, meninges, spinal vasculature, and respiratory diverticula. Among these, paramedullary diverticula and the extradural dorsal spinal vein may leave behind osteological correlates in the form of pneumatic foramina and fossae, and a bilobed geometry of ...
Jessie Atterholt   +5 more
wiley   +1 more source

Skeletal pathologies in extant crocodilians as a window into the paleopathology of fossil archosaurs

open access: yesThe Anatomical Record, EarlyView.
Abstract Crocodilians, together with birds, are the only extant relatives to many extinct archosaur groups, making them highly important for interpreting paleopathological conditions in a phylogenetic disease bracketing model. Despite this, comprehensive data on osteopathologies in crocodilians remain scarce.
Alexis Cornille   +6 more
wiley   +1 more source

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