 |
Business | Industries | Finance | Tax |
| Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|||||
| First Prev [ 1 2 ] Next Last |
| Amphibia
| ||||||||
|---|---|---|---|---|---|---|---|---|
| Scientific classification | ||||||||
| ||||||||
| Orders | ||||||||
|
Subclass Labyrinthodontia - extinct Subclass Lepospondyli - extinct Subclass Lissamphibia Urodela Anura Gymnophiona |
Amphibians developed with the characteristics of pharyngeal slits/ gills, a dorsal nerve cord, a notochord, and a post-anal tail at different stages of their life. They have persisted since the dawn of tetrapods 390 million years ago in the Devonian period, when they were the first four-legged animals to develop lungs. During the following CarboniferousThe Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period (about 280 million years before the present (BP)) to the beginning of the Permian period (about 340 million Years BP). As with most older geol period they also developed the ability to walk on land to avoid aquatic competition and predation while allowing them to travel from water source to water source. As a group they maintained the status of the dominant animal for nearly 75 million years. Throughout their history they have ranged in size from the 15 foot long Devonian IchthyostegaIchthyostega is an early tetrapod and lived during the Late Devonian period. Being one of the first animals with legs, arms, and finger bones, Ichthyostega was a hybrid between a fish and an amphibian. Ichthyostega had legs but its limbs probably weren't, to the slightly smaller 6 foot long EryopsEryops ("big eye") is a genus of extinct, semi-aquatic amphibian found primarily in the Permian-aged Admiral Formation of Archer County, Texas, but fossils are also found in New Mexico and parts of the eastern United States. Eryops averaged a little over, and down to the tiny 1 centimeter long Psyllophryne didactyla , commonly known as the Brazilian Gold Frog. Amphibians have mastered almost every climate on earth from the hottest deserts to the frozen arctic, and have adapted to climatic change with ease.
Traditionally the amphibians are taken to include all tetrapods that are not amniotes. Recent amphibians all belong to a single subgroup of these, called the Lissamphibia. Recently there has been a tendency to restrict the class Amphibia to the Lissamphibia, i.e. to exclude tetrapods that are not more closely related to modern forms than they are to modern reptiles, birds, and mammals.
There are two ancientFor the span of recorded history starting roughly 5,000-5,500 years ago, see Ancient history''. Ancient is a Norwegian band that, while not really troll metal, had troll metal themes on their 1994 EP 'Trolltaar'. The band started as a solo project of guit, extinct, subclassIn object-oriented programming, subclass is a class that is derived from another class or classes. A subclass is also called a child class or derived class. The class from which a subclass is derived is known as a parent class or base class. Object-orientes:
Of the remaining modern subclass Lissamphibia there are three orderOrder is one of the levels of scientific classification of organisms. Orders are grouped into classes and themselves contain families. The standard groupings of taxonomy from most general to most specific are: Domain Kingdom Phylum (animals); Division (pls:
Authorities disagree on whether Salientia is a Superorder that includes the order Anura, or whether Anura is a sub-order of the order Salientia. In effect Salientia includes all the Anura plus a single Triassic proto-frog species, Triadobatrachus massinoti . Practical considerations seem to favour using the former arrangement now.
| Politics | Business | Finance |
 |
 |
 |
|