It can
be distinguished from the horn shark (Heterodontus francisci)
by the low supraorbital ridges, a first dorsal that
originates over the pectoral base and large spots that
are larger than half of eye length, although some specimens
have no spots and a subtle bar between the supraorbital
ridges. The Cortez bullhead shark (Heterodontus sp.)
is known from the Sea of Cortez and has moderately high
supraorbital ridges, with the height of the eye being
equal to the distance between the top of the eye and
the top of the surpaorbital ridge. The ridges are less
squared off posteriorly and longer anteriorly than in
H. francisci The snout is longer than H. francisci and
the dorsal fins higher and more falcate than in H. francisci
and H. mexicanus. The dorsum and lateral surface of
the Cortez bullhead shark is brown and without spots,
their is no pale line between the supraorbital ridges
and the ventrum is lighter in color. This species is
also found in the Sea of Cortez to Peru.
