It is known only from a partial skull recovered from Barremian-age rocks of the Lower Cretaceous Vectis Formation (Wealden Group) of the Isle of Wight.

This skull, BMNH R 177, is short and wide, with a eusuchian-like palate and inferred enlarged posterior teeth that would have been suitable for crushing.

Hylaeochampsa is the type genus of the family Hylaeochampsidae, which also includes Iharkutosuchus from the Late Cretaceous of Hungary.

James Clark and Mark Norell positioned it as the sister group to Crocodylia.

[4] The cladogram below results from a 2011 Buscalioni et al. phylogenetic study:[5] Hylaeochampsa vectiana† Iharkutosuchus† Pietraroiasuchus ormezzanoi† Pachycheilosuchus trinquei† Allodaposuchus† Crocodylia