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Amniotes

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Infraphylum:	Tetrapoda
Microphylum:	Amniota

Extant subgroups

Synapsida

Mammalia (mammals)

Sauropsida

    Anapsida
       Testudines (turtles)
    Diapsida
       Lepidosauria
          Squamata ( lizards and snakes)
          Sphenodontida (tuatara)
       Archosauria
          Crocodilia ( crocodileCrocodylus Osteolaemus Tomistoma A crocodile can be any of the 14 species of large, water-loving reptiles in the family Crocodylidae (sometimes classified instead as the subfamily Crocodylinae . The term is also used more loosely to include all members ofs and alligatorThis article refers to the large reptile. For information on the place, see Alligator, Mississippi. Alligators American alligator : Animalia : Chordata : Reptilia : Crocodylia : Alligatoridae Alligator Alligator mississippiensis ''Alligator sinensis Alligs)
          Aves (birds)

The amniotes are a group of vertebratePetromyzontidae ( lampreys) Placodermi extinct Chondrichthyes (cartilaginous fish) Acanthodii extinct Actinopterygii (ray-finned fish) Actinistia ( coelacanths) Dipnoi ( lungfish) Amphibia ( amphibians) Reptilia ( reptiles) Aves ( birds) Mammalia ( mammals, comprising the mammals, birdFor other meanings of bird see bird (disambiguation). Many see text Birds are bipedal, warm-blooded, egg-laying vertebrates characterized primarily by feathers, forelimbs modified as wings, and hollow bones. There are almost 9000 known species of birds ins, and various other groups collectively referred to as reptileCrocodilia Crocodilians Rhynchocephalia Tuataras Squamata Suborder Sauria Lizards Suborder Serpentes Snakes Testudines Turtles Superorder Dinosauria Saurischia Ornithischia The reptiles are a group of vertebrate animals. Most reptiles are tetrapods, and ts. Most are adapted to a fully terrestrial existence, although some are secondarily aquatic. In contrast, amphibians are only partially terrestrial and pass through an aquatic stage. The name comes from the amniotic egg, in which the developing embryo is protected by a series of membranes and a hard shell which resists desiccation. Their kidneys and large intestines are also designed to retain water. Most mammals do not lay eggs, but corresponding structures may be found inside the placenta. Most reptiles also have protective scales, which are modified in birds to form feathers.

There are three main lines of amniotes, which may be distinguished by the structure of the skull and in particular the number temporal fenestrae (openings) behind the eye. In anapsids there are none, in synapsids there is one, and in most diapsids there are two.

The skeletal remains of amniotes can be identified by their having at least two pairs of sacral ribs and an astragalus bone in the ankle.

Chordates

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Topics: Amniote, Amniotic Sac, Amniotic Band Syndrome...

Amniotic sacThe amniotic sac is a tough but thin transparent pair of membranes which holds a developing embryo (and later fetus) until shortly before birth. The inner membrane, the amnion contains the amniotic fluid and the fetus. The outer membrane, the chorion cont

Amniotic Band SyndromeAmniotic Band Syndrome is a congenital disorder caused by entrapment of fetal parts (usually a limb or digits) in fibrous amniotic bands while in utero. Epidemiology Amniotic Band Syndrome (ABS) affects approximately 1:1200 live births. It is also believe

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