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In typical early tetrapod posture, the upper arm and upper leg extended nearly straight horizontal from its body, and the forearm and the lower leg extended downward from the upper segment at a near right angle. The body weight was not centered over the limbs, but was rather transferred 90 degrees outward and down through the lower limbs, which ...
Centipedes have one pair of legs per body segment, with typically around 50 legs, but some species have over 200. The terrestrial animals with the most legs are the millipedes. They have two pairs of legs per body segment, with common species having between 80 and 400 legs overall – with the rare species Illacme plenipes having up to 750 legs.
Limbs are attached to the torso via girdles, either the pectoral girdle for the forelimbs, or the pelvic girdle for the hindlimbs.In terrestrial tetrapods, the pectoral girdles are more mobile, floating over the rib cage connected only via the clavicles (to the sternum) and numerous muscles; while the pelvic girdles are typically fused together anteriorly via a fibrocartilaginous joint and ...
A tetrapod is a form of wave-dissipating concrete block used to prevent erosion caused by weather and longshore drift, primarily to enforce coastal structures such as seawalls and breakwaters. Tetrapods are made of concrete , and use a tetrahedral shape to dissipate the force of incoming waves by allowing water to flow around rather than ...
In tetrapod anatomy, leg is used to refer to the entire limb. In human medicine, the precise definition refers [ 2 ] [ 3 ] [ 4 ] only to the segment between the knee and the ankle . This lower segment is also called the shank , [ 5 ] [ 6 ] and the front (anterior) of the segment is called the shin or pretibia .
However, this group represents a paraphyletic grade of primitive stem-tetrapods and is not used by many modern researchers. Phylogenetic analysis has shown Ichthyostega is intermediate between other primitive stegocephalian stem-tetrapods. The evolutionary tree of early stegocephalians below follows the results of one such analysis performed by ...
The appendicular skeleton is the portion of the vertebrate endoskeleton consisting of the bones, cartilages and ligaments that support the paired appendages (fins, flippers or limbs). In most terrestrial vertebrates (except snakes , legless lizards and caecillians ), the appendicular skeleton and the associated skeletal muscles are the ...
The water-based lateral line system was used substantially by these aquatic tetrapods to detect danger from predators. [2] Within the Osteichthyan diversification, there were no changes related to respiration in the transition as can be seen by the nasal region and palatal morphology in elpistostegalid fishes.