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The hearts of amphibians have three chambers, two atria and one ventricle. They have a urinary bladder and nitrogenous waste products are excreted primarily as urea . Most amphibians lay their eggs in water and have aquatic larvae that undergo metamorphosis to become terrestrial adults.
While reptiles and amphibians can be quite similar externally, the French zoologist Pierre André Latreille recognized the large physiological differences at the beginning of the 19th century and split the herptiles into two classes, giving the four familiar classes of tetrapods: amphibians, reptiles, birds and mammals.
A lymph heart is an organ which pumps lymph in lungfishes, amphibians, reptiles, and flightless birds back into the circulatory system. [1] [2] In some amphibian species, lymph hearts are in pairs, and may number as many as 200 in one animal the size of a worm, while newts and salamanders have as many as 16 to 23 pairs of lymph hearts.
Quadrupedalism is a form of locomotion where animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (from Latin quattuor for "four", and pes , pedis for "foot").
Reptiles, from Nouveau Larousse Illustré, 1897–1904, notice the inclusion of amphibians (below the crocodiles). In the 13th century, the category of reptile was recognized in Europe as consisting of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, lizards, assorted amphibians, and worms", as recorded by Beauvais in his Mirror of Nature. [7]
Tetrapod limbs which have evolved into fin-like structures are usually (but not always) called "flippers" rather than fins. The dorsal structure on cetaceans is called the "dorsal fin" and the large cetacean tails are referred to primarily as flukes but occasionally as "caudal fins"; neither of these structures are flippers.
Well, many cat owners know the classic tell-tale signs of a happy cat: purring, rubbing against a human's legs and feet, kneading, meowing, or asking for attention with a touch of their paw. You ...
Many animals, especially the arboreal species, have prehensile forelimbs adapted for grasping and climbing, while some (mostly primates) can also use hindlimbs for grasping. Some animals ( birds and bats ) have expanded forelimbs (and sometimes hindlimbs as well) with specialized feathers or membranes to achieve lift and fly .