Results 141 to 150 of about 19,866 (206)

Redescription of the Triassic cynodont Cistecynodon parvus and reassessment of its phylogeny

open access: yesThe Anatomical Record, EarlyView.
Abstract Cynodontia is an important subclade of Therapsida that first occurred in the late Permian. It includes extinct subclades which are the non‐mammaliaform cynodonts and Mammaliaformes, with the latter ultimately giving rise to crown mammals. The systematics of non‐mammaliaform cynodonts has been extensively studied and is relatively well‐resolved,
Erin S. Lund   +4 more
wiley   +1 more source

The musculature and skeleton of the pelvic fin of the crocodile shark, Pseudocarcharias kamoharai (Matsubara, 1936) (Elasmobranchii: Lamniformes): Morphology and sexual dimorphism

open access: yesThe Anatomical Record, EarlyView.
This work brings new information on the sexual characteristics of the crocodile shark (Pseudocarcharias kamoharai) exploring the pelvic fin musculature, as well as the siphon sac and the musculature and skeleton of the clasper. Our paper is the first to point out clearly the sexual dimorphism related exclusively to the pelvic fin musculature in males ...
Laura F. Mianutti   +2 more
wiley   +1 more source

The mechanism of labor in nonhuman primates: A look inside

open access: yesThe Anatomical Record, EarlyView.
Abstract While in humans, the flexed position of the fetus and its rotating course down the birth canal are well documented, in other primates the mechanism of labor is unknown. Despite the lack of comparative data, it is commonly assumed that the human obstetric mechanism is unique, and anthropologists have disputed when and why the transition to the ...
Melissa K. Stoller
wiley   +1 more source

Developmental morphology of claspers and clasper‐glands during maturation in Potamotrygon wallacei (Chondrichthyes: Potamotrygoninae)

open access: yesThe Anatomical Record, EarlyView.
Abstract The claspers are the copulatory organs in male elasmobranchs, responsible for directing the semen into the female cloaca (C). However, the microscopic morphology of the claspers remains poorly understood. This study describes the morphology of the claspers and clasper glands (CGs) of cururu stingray (Potamotrygon wallacei) at different ...
Matheus Samuel Cunha Braga   +4 more
wiley   +1 more source

SOX6 is expressed in various cell lineages in the developing mouse heart and contributes to proper valvuloseptal development

open access: yesThe Anatomical Record, EarlyView.
Abstract Cells derived from the endocardium, epicardium, cardiac neural crest, and second heart field play a critical role in the formation of the valvuloseptal structures of the heart. Previous studies have shown that the expression of the transcription factor SOX9 in these cell populations is essential in the regulation of this process.
Hannah G. Tarolli   +6 more
wiley   +1 more source

Morphophysiological dynamics of the proximal post‐testicular ducts in Crotalus durissus Linnaeus, 1758 (Squamata: Viperidae)

open access: yesThe Anatomical Record, EarlyView.
Abstract The organization and function of reptilian excurrent ducts remain poorly characterized, particularly in Neotropical snakes. We provide the first integrative morphological, histochemical, immunohistochemical, and ultrastructural analysis of the proximal post‐testicular ducts of Crotalus durissus across reproductive stages.
Flávia Cappuccio de Resende   +9 more
wiley   +1 more source

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