The Lowoceratidae is a small family of discosorids, early nautiloid cephalopods, from the Middle Silurian in which the characteristic bullette is found only in early growth stages.

Both are strongly compressed, exogastric brevicones with the ventral side more narrowly rounded than the dorsal.

Shells enlarge moderately to the middle of the mature body chamber, then contract gently toward the aperture.

The siphuncle of Tuyloceras, genotype T. percurvatum, starts off with slender, subquadrate segments with thick rings and swollen bullettes, but later in life the segments become expanded, rings thinner, and bullettes simple and unswollen.

Lowoceras, genotype L. southamptonense, is like Tuylocrdas, but with endocones in the siphuncle like the later Discosorus.