[5] Fossils are known from the Ruthin Quarry in Glamorgan, Wales, one of several Late Triassic to Early Jurassic British fissure deposits.

The type species, T. thomasi, was named in 1957 along with the possible trilophosaur Variodens inopinatus from Somerset, England.

[1] Although originally classified as a trilophosaur, Tricuspisaurus was reclassified as a procolophonid in 1993 by paleontologists Hans-Dieter Sues and Paul E.

[2] This was due to similarities between its tricuspid teeth and those of the newly described procolophonid Xenodiphyodon.

Along with Tricuspisaurus, Variodens and Trilophosaurus jacobsi were also considered to be procolophonids.