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An arch extending from the top of the centrum is called a neural arch, while the haemal arch or chevron is found underneath the centrum in the caudal vertebrae of fish. The centrum of a fish is usually concave at each end (amphicoelous), which limits the motion of the fish.
An arch extending from the top of the centrum is called a neural arch, while the haemal arch is found underneath the centrum in the caudal (tail) vertebrae of fish, most reptiles, some birds, some dinosaurs and some mammals with long tails. The vertebral processes can either give the structure rigidity, help them articulate with ribs, or serve ...
The first arch, as the first to form, separates the mouth pit or stomodeum from the pericardium. By differential growth the neck elongates and new arches form, so the pharynx has six arches ultimately. Each pharyngeal arch has a cartilaginous stick, a muscle component that differentiates from the cartilaginous tissue, an artery, and a cranial ...
The body of the vertebra and the vertebral arch form the vertebral foramen, the larger, central opening that accommodates the spinal canal, which encloses and protects the spinal cord. Vertebrae articulate with each other to give strength and flexibility to the spinal column, and the shape at their back and front aspects determines the range of ...
The earliest recorded incidence of a Weberian apparatus is from the fossil fish Santanichthys diasii dating from the Early Cretaceous of Northeastern Brazil. In the aforementioned taxon, the Weberian apparatus is fairly developed; there is a distinguishable intercalarium and a tripus which articulate with the second and third vertebrae ...
The second arch becomes the hyoid and jaw support. [5] In fish, the other posterior arches contribute to the brachial skeleton, which support the gills; in tetrapods the anterior arches develop into components of the ear, tonsils, and thymus. [7] The genetic and developmental basis of pharyngeal arch development is well characterized.
Neural spine of Maraapunisaurus as drawn by E.D. Cope with parts labeled. The key rebbachisaurid features are the spinopostzygapophyseal laminae that extends dorsomedially from the postzygapophyses to join and form the postspinal lamina, and the pneumatic neural spine and arch.
Cartilaginous fish; Genus Species Location Material Notes Images Acrodontidae indet. [2] ... [46] and a possible tooth and neural arch from two other specimens." [43]