Definition of cynodont in US English:



  • A fossil carnivorous mammal-like reptile of the late Permian and Triassic periods, with well-developed specialized teeth.

    Suborder Cynodontia, order Therapsida: several families

    • ‘In both therocephalians and cynodonts, early stages in the evolution of the secondary palate consist of the gradual enlargement and final coalescence of bony plates emanating from the medial margins of the maxilla and palatine bones.’
    • ‘Some later cynodonts had both joints close together and in operation at the same time.’
    • ‘In advanced herbivorous cynodonts, like the tritylodonts, the ability to move the lower jaws in a fore-aft direction was exploited for the purpose of cutting up plant material by the cheek dentition.’
    • ‘The tritylodonts were among the last of the cynodonts to appear.’
    • ‘The cynodonts are sometimes thought to be mammalian ancestors, but there are minor features which debar them, some believe, from such position.’
    • ‘Luo and coworkers find that Haramiyavia is not even a mammaliform but an aberrant cynodont.’
    • ‘Evidence for therapsid fur centers on the presence of infraorbital pits and ridges in some lower Triassic cynodonts.’
    • ‘Among therapsids, this condition is also present in gorgonopsians and basal therocephalians, but not dinocephalians, anomodonts, or cynodonts.’
    • ‘Rhyncosaurs and cynodonts are far more common, and in fact the rhyncosaur Scaphonix accounts for half of all tetrapod fossils.’
    • ‘The Allotheria are so different from anything else that one can almost imagine their derivation from an entirely separate line of cynodonts.’
    • ‘Probably the most informative analysis of mammal-like reptiles as transitional forms is the one which focuses, in detail, on the presumed changes from advanced cynodonts to the earliest mammals.’
    • ‘The complex cheek teeth and secondary palate show that the cynodonts were able to chew and breathe at the same time.’
    • ‘Only two clades of nonmammalian cynodont are known from the Lower Jurassic: tritylodontids and tritheledontids.’
    • ‘The structure is unusually large in cynodonts and mammaliforms.’
    • ‘By Early Triassic times, cynodonts had diverged into large predaceous carnivores such as Cynognathus and moderate large omnivorous and herbivorous types such as Trirachodon and Diademodon.’
    • ‘The effect of this trend among cynodonts, toward a single lower jaw bone, was to make the jaws stronger.’
    • ‘These advanced tiny cynodonts were probably very successful, but remain poorly known, because such tiny remains are only rarely fossilized.’
    • ‘Prior to the early mammal Sinoconodon, the lower jaws of advanced nonmammalian cynodonts such as Probainognathus maintained substantial differences from those of early mammals.’
    • ‘The dicynodonts as a whole lasted some 50 million years, and the only group of therapsids to outlive them were the cynodonts, which were the direct ancestors of the mammals.’
    • ‘The model of therapsid relationships proposed by Rubidge and Sidor implies that a crista choanalis evolved at least three times, in biarmosuchians, eutherocephalians, and cynodonts.’


Late 19th century: from Greek kuōn, kun- ‘dog’ + odous, odont- ‘tooth’.