Definition of pelycosaur in English:



  • A large fossil reptile of the late Carboniferous and Permian periods, typically having a line of long bony spines along the back supporting a sail-like crest.

    Order Pelycosauria, subclass Synapsida: several families and genera, including Dimetrodon and Edaphosaurus

    • ‘The transition between pelycosaurs and therapsids has not been documented.’
    • ‘It is a box-like construction, more like a pelycosaur than a mammal, with the large flat maxillae forming the sides, the nasal the top, the the tall premaxilla at the rostral end.’
    • ‘This gap is all the more extreme because pelycosaurs and therapsids are each large, internally-diverse groups.’
    • ‘A characteristic pelycosaur was Dimetrodon, a large predator from the Permian of Texas.’
    • ‘An interesting example of convergent evolution is seen between these pelycosaurs and the unrelated dinosaurs.’
    • ‘Whereas the Early Permian pelycosaur record is extensive, Carboniferous pelycosaur remains are rare and poorly known.’
    • ‘It may be intermediate in structure between the pelycosaurs and the therapsids.’
    • ‘All groups of pelycosaurs went extinct by the end of the Permian.’
    • ‘Between the Carboniferous pelycosaurs and the first Jurassic mammals, the jaw articulation changed.’
    • ‘Nevertheless these primitive animals were more advanced on the road the to mammalian evolution, and, like the pelycosaurs, diverged along several lines as herbivores, carnivores, or omnivores.’


Late 19th century: from Greek pelux, peluk- ‘bowl’ + sauros ‘lizard’.