Author: Müller and Henle, 1839
Diagnostic Features:
Body cylindrical or moderately depressed, with prominent ridges on sides. Head very broad and flattened, without lateral flaps of skin, snout truncated; eyes laterally situated on head, without subocular pockets; spiracles much smaller than eyes, behind but not below them; gill slits very large, fifth well separated from fourth; internal gill slits with unique filter screens, consisting of transverse lamellae that cross each gill slit, with ramose processes on their inner surfaces that interconnect to form the filters; nostrils with rudimentary barbels and no circumnarial folds and grooves; mouth ext'remely large, terminal on head, and transverse, without a symphyseal groove on chin; teeth not strongly differentiated in jaws, with a medial cusp, no cusplets and no labial root lobes; tooth rows extremely numerous, in over 300 rows in either jaw of adults and subadults. Caudal peduncle with strong lateral keels and an upper precaudal pit. First dorsal much larger than second, first dorsal with origin well anterior to the pelvic origins, and insertion over the pelvic bases; pectoral fins very large, relatively narrow and falcate, much larger than pelvic fins, with fin radials expanded into fin web nearly to its distal edge; pelvic fins somewhat smaller than first dorsal but slightly larger than second dorsal and anal fins; anal fin about as large as second dorsal, with its origin about opposite first third of second dorsal base; anal fin with broad base and angular apex, separated by a space somewhat greater than base length from lower caudal origin; caudal fin with its upper lobe at a high angle above the body axis, less than a third as long as the entire shark, with a vestigial terminal lobe and subterminal notch and a very strong ventral lobe or a very short one. Supraorbital crests present on cranium, these laterally expanded. Valvular intestine probably of ring type. A unique colour pattern of light spots and vertical and horizontal stripes, in the form of a checkerboard.
Interest to Fisheries:
See the account of the single species.
Remarks:
The spelling Rhiniodontidae, is an amended version of Rhinodontes Müller and Henle, 1839 first mentioned in Compagno (1973c).