楔齿龙类
楔齿龙类（学名：Spenacodontia）是个演化支，包括楔齿龙科与牠们所有后代（包括哺乳类）。牠们首次出现于晚宾夕法尼亚纪。共有衍征包括：上颌骨的内部变厚、大型的犬齿型牙齿、前上颌骨的牙齿位在齿槽里。所有其他（姐妹分类单元与更原始的物种）合弓动物演化支的牙齿都位在浅的齿槽里。
基础的楔齿龙类构成早期盘龙目到兽孔目祖先的演化过渡阶段。有研究认为楔齿龙类是原始兽孔目动物。
Sphenacodontia
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Sphenacodontia 楔齿龙类
Sphenacodontia is a stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes Haptodus baylei, Haptodus garnettensis and Sphenacodon ferox, but not Edaphosaurus pogonias". They first appear during the Late Pennsylvanian epoch.
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