Late 19th century; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist. From scientific Latin Dicynodontia, former group name + -an.
Definition of dicynodontian in US English:
dicynodontian
adjectiveˌdʌɪsɪnəˈdɒntɪən
rare
Dicynodont.
Origin
Late 19th century; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist. From scientific Latin Dicynodontia, former group name + -an.