Original: Advanced features that ties it in with the reptilian rather than amphibian group is unfused ankle bones, lack of labyrinthodont infolding of the dentin, a lack of an otic notch and a generally small skull.
Simplified: Advanced features that ties it in with the amniote rather than amphibian group is unfused ankle bones, lack of labyrinthodont infolding of the dentine in teeth, a lack of an otic notch and a generally small skull.