dimetrodon
Concise Oxford English Dictionary © 2008 Oxford University Press:
dimetrodon /dʌɪˈmiːtrədɒn/
▶noun a large fossil carnivorous mammal-like reptile of the Permian period, with long spines on its back supporting a sail-like crest.
– origin mod. L., from di- ‘twice’ + Gk metron ‘measure’ + odous, odont- ‘tooth’ (taken in the sense ‘two long teeth’).
'dimetrodon' also found in these Oxford entries:
