Eilenodontinae are an extinct clade of reptiles belonging to Sphenodontia. They are either considered a subgroup of Opisthodontia,[1] or Sphenodontidae.[2] They had deep jaws with broad, closely packed teeth with thick enamel and noticeable wear facets. They were likely herbivorous, and probably chewed with a proal (forward stroke) movement, with food shredded between the edges of opposing sharp-edged wear facets. Members of the group are known from South America, North America and Europe.[3] The earliest known member of the group, Sphenotitan, is known from the Late Triassic of South America.[2] while the youngest members are known from the Late Cretaceous of South America.[4] The group contains some of the largest known sphenodontians, with Priosphenodon suggested to be the largest known non aquatic sphenodontian, with an estimated body length of over 1 metre (3.3 ft).[5]