It is the type genus of the family Dercetidae, a group of slender, elongate aulopiforms, which were related to modern lizardfish and grinners.

It is known from the Late Cretaceous of Europe, the Middle East, and western North America.

[1] The initial type species, D. scutatus Agassiz, 1834 from the Campanian of Germany (Baumberge Formation), is known from a now-lost specimen and is thus considered a nomen nudum.

[1][3] Many other dercetid taxa were initially classified into Dercetis before being moved to their own genera.

It inhabited open marine environments of the northern Western Interior Seaway.