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Tetrapod. A tetrapod (/ ˈtɛtrəˌpɒd /; [5] from Ancient Greek τετρα- (tetra-) 'four' and πούς (poús) 'foot') is any four- limbed vertebrate animal of the superclass Tetrapoda (/ tɛˈtræpədə /). [6] Tetrapods include all extant and extinct amphibians and amniotes, with the latter in turn evolving into two major clades, the ...
Reptile. See text for extinct and stem groups. Reptiles, as commonly defined, are a group of tetrapods with usually an ectothermic ('cold-blooded') metabolism and amniotic development. Living reptiles comprise four orders: Testudines (turtles), Crocodilia (crocodilians), Squamata (lizards and snakes), and Rhynchocephalia (the tuatara).
Fish physiology is the scientific study of how the component parts of fish function together in the living fish. [2] It can be contrasted with fish anatomy, which is the study of the form or morphology of fishes. In practice, fish anatomy and physiology complement each other, the former dealing with the structure of a fish, its organs or ...
The heart is muscular and located in the anterior part of the visceral mass. In the great majority of species, it has two chambers; an auricle, which receives haemolymph from the gill or lung, and a ventricle, which pumps it into the aorta. However, some primitive gastropods possess two gills, each supplying its own auricle, so that their heart ...
Swim bladder. The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish (but not cartilaginous fish [1]) to control their buoyancy, and thus to stay at their current water depth without having to expend energy in swimming. [2] Also, the dorsal position of the swim ...
The tuatara is the only living tetrapod with well-developed gastralia and uncinate processes. In the early tetrapods, the gastralia and ribs with uncinate processes, together with bony elements such as bony plates in the skin (osteoderms) and clavicles (collar bone), would have formed a sort of exoskeleton around the body, protecting the belly ...
Marine vertebrates are vertebrates that live in marine environments. These are the marine fish and the marine tetrapods (primarily seabirds, marine reptiles, and marine mammals). Vertebrates are a subphylum of chordates that have a vertebral column (backbone). The vertebral column provides the central support structure for an internal skeleton.
[3] Through convergent evolution , lungfishes have evolved internal nostrils similar to the tetrapods' choana , [ 4 ] and a brain with certain similarities to the Lissamphibian brain (except for the Queensland lungfish, which branched off in its own direction about 277 million years ago and has a brain resembling that of the Latimeria ).