The tubercles as inferior articular processes of the fifth sacral vertebra, known as the sacral cornea, are projected downward, and are connected to the cornua of the coccyx.
The cephaloskeleton has a dorsal cornua of consistent width until it comes to a point at the posterior end.
It is continuous behind with a flattened triangular area, the trigonum collaterale, situated between the posterior and inferior cornua.
The "cornua" of the sacrum may be palpated with a finger; the sacrococcygeal membrane lies between and inferior to these.
Dorsoventrally compressed; orbits face dorsally; widely splayed pectoral fins, with cornua common; no post-pectoral plates; plates ornamented with linear rows of tubercles; strictly benthonic?
