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Some amphibians such as newts and salamanders, and some frogs such as fire-bellied toads and wood frogs. Some reptiles such as crocodilians, turtles, water snakes and marine iguanas. Waterbirds, especially penguins, waterfowls, storks and shorebirds. Some rodents such as beavers, muskrats and capybaras.
The high degree of overlap between marine mammal species richness and areas of human impact on the environment is of concern. [5] Most marine mammals, such as seals and sea otters, inhabit the coast. Seals, however, also use a number of terrestrial habitats, both continental and island.
The first amphibians appeared on land in the Carboniferous. During the Triassic , mammals and dinosaurs appeared, the latter giving rise to birds in the Jurassic . Extant species are roughly equally divided between fishes of all kinds, and tetrapods.
The largest living amphibian is the 1.8 m (5 ft 11 in) Chinese giant salamander (Andrias davidianus) [41] but this is a great deal smaller than the largest amphibian that ever existed—the extinct 9 m (30 ft) Prionosuchus, a crocodile-like temnospondyl dating to 270 million years ago from the middle Permian of Brazil. [42]
While the early amniotes resembled their amphibian ancestors in many respects, a key difference was the lack of an otic notch at the back margin of the skull roof. In their ancestors, this notch held a spiracle , an unnecessary structure in an animal without an aquatic larval stage. [ 25 ]
Synapsida [a] is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and birds).
A major difference between early tetrapodomorph fishes and early tetrapods was in the relative development of the front and back skull portions; the snout is much less developed than in most early tetrapods and the post-orbital skull is exceptionally longer than an amphibian's. A notable characteristic that make a tetrapod's skull different ...
Marine mammals are aquatic mammals that rely on the ocean for their existence. They include animals such as sea lions, whales, dugongs, sea otters and polar bears. Like other aquatic mammals, they do not represent a biological grouping. [26] The humpback whale is a fully aquatic marine mammal.