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In 2004, the International Union for Conservation of Nature (IUCN) reported stating that currently birds, [172] mammals, and amphibians extinction rates were at minimum 48 times greater than natural extinction rates—possibly 1,024 times higher. In 2006, there were believed to be 4,035 species of amphibians that depended on water at some stage ...
The earliest tetrapods are grouped under class Amphibia, although several of the groups are more closely related to amniotes than to modern day amphibians. Traditionally, birds are not considered a type of reptile, but crocodiles are more closely related to birds than they are to other reptiles, such as lizards.
The sexual dimorphism in amphibians and reptiles may be reflected in any of the following: anatomy; relative length of tail; relative size of head; overall size as in many species of vipers and lizards; coloration as in many amphibians, snakes, and lizards, as well as in some turtles; an ornament as in many newts and lizards; the presence of ...
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia.In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals).
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors, including Komodo dragons.
The axolotl can grow up to 12 inches and weigh anywhere from three to eight pounds, and its average lifespan in the wild is 10-15 years. Most axolotls are dark brown with some black speckling, but ...
A cloaca (/ k l oʊ ˈ eɪ k ə / ⓘ kloh-AY-kə), pl.: cloacae (/ k l oʊ ˈ eɪ s i / kloh-AY-see or / k l oʊ ˈ eɪ k i / kloh-AY-kee), or vent, is the rear orifice that serves as the only opening for the digestive , reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilaginous ...
As such, there are over 80 species of unisex reptiles (mostly lizards but including a single snake species), amphibians and fishes in nature for which males are no longer a part of the reproductive process. [43] A female produces an ovum with a full set (two sets of genes) provided solely by the mother.