Paleontology #11a
SYNAPSIDS
 Pelycosauria     
----     Therapsida   Two shearing mechanisms  Dinocephalian therapsids   Dicynodont therapsids   Theriodont therapsids 
--       
-- --   |
rev. Aug. 2017
|
Pelycosauria
---- Therapsida Two shearing mechanisms Dinocephalian therapsids Dicynodont therapsids Theriodont therapsids
--
-- -- |