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For instance, descendants of the first reptiles include modern reptiles, mammals and birds; the agnathans have given rise to the jawed vertebrates; the bony fishes have given rise to the land vertebrates; a group of amphibians, the labyrinthodonts, have given rise to the reptiles (traditionally including the mammal-like synapsids), which in ...
Unlike amphibians, reptiles do not have an aquatic larval stage. Most reptiles are oviparous, although several species of squamates are viviparous, as were some extinct aquatic clades [6] – the fetus develops within the mother, using a (non-mammalian) placenta rather than contained in an eggshell. As amniotes, reptile eggs are surrounded by ...
The skull of Python reticulatus.. The skull of a snake is a very complex structure, with numerous joints to allow the snake to swallow prey far larger than its head.. The typical snake skull has a solidly ossified braincase, with the separate frontal bones and the united parietal bones extending downward to the basisphenoid, which is large and extends forward into a rostrum extending to the ...
The world's smallest known vertebrate, Paedophryne amauensis, sitting on a U.S. dime.The dime is 17.9 mm in diameter, for scale. The word amphibian is derived from the Ancient Greek term ἀμφίβιος (amphíbios), which means 'both kinds of life', ἀμφί meaning 'of both kinds' and βίος meaning 'life'.
The earliest marine reptiles arose in the Permian. During the Mesozoic many groups of reptiles became adapted to life in the seas, including ichthyosaurs, plesiosaurs, mosasaurs, nothosaurs, placodonts, sea turtles, thalattosaurs and thalattosuchians. Marine reptiles were less numerous after mass extinction at the end of the Cretaceous.
The oldest known animal that may have been an amniote, a reptile rather than an amphibian, is Casineria [3] [4] (though it has also been argued to be a temnospondyl amphibian). [5] A series of footprints from the fossil strata of Nova Scotia, dated to 315 million years, show typical reptilian toes and imprints of scales. [6]
Scientists consider the blue whale, which grows up to 110 feet (33.5 meters) long, to be the largest known animal ever to exist on the planet. But it’s possible that the 202 million-year-old ...
Lizard is the common name used for all squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, [1] ranging across all continents except Antarctica, as well as most oceanic island chains.