Eilenodontinae are an extinct clade of reptiles belonging to Sphenodontia.

[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.

[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.