Synapsida

[n] - extinct reptiles of the Permian to Jurassic considered ancestral to mammals
Found on http://www.webdictionary.co.uk/definition.php?query=Synapsida

Synapsida

subclass Synapsida noun extinct reptiles of the Permian to Jurassic considered ancestral to mammals
Found on http://wordnetweb.princeton.edu/perl/webwn?s=Synapsida

Synapsida

(from the article `vertebrate`) ...temporal openings high up on skull; fishlike; spindle-shaped body; high tail fin; triangular dorsal fin; paddlelike legs; marine.Subclass ... ...tail (i.e., with the lower lobe longer than the upper). Limbs paddle-like; snout often elongated and beaklike.†Subclass Synapsida (mammal-like ... The...
Found on http://www.britannica.com/eb/a-z/s/199

Synapsida

The synapsida are a subclass of mammal-like reptiles now extinct.
Found on http://www.probertencyclopaedia.com/browse/BSB.HTM
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