What is "pleuroacanthitidae"

Pleuroacanthitidae is a small family of Lower Jurassic ammonoids that combines some characters of the Lytoceratida, Phylloceratida, and earliest Ammonitida, as well as special characters of its own. It is subdivided (Arkell, et al., 1957) into two subfamilies, each represented by a single genus, the Pleuroacanthitinae containing Pleuroacanthites and the Analytoceratina containing Analytoceras.