a rare shark classified as the only shark in the genus Scymnodalatias. This genus is in the family Squalidae and the order Squaliformes, which includes the dogfish sharks, bramble sharks and rough sharks. The Sherwood dogfish shark was formerly classified in the genus Scymnodon but was reclassified due to the lack of spines on the front of its dorsal fins and the location of its front dorsal fin. The scientific name of the sherwood dogfish shark is S. sherwoodi. The body color is blackish brown, and the snout is somewhat flattened. The two dorsal, or top, fins lack the frontal spine that is commonly found in other sharks. The rear dorsal fin is slightly larger than the front dorsal, which is located at mid-body well behind the pectoral fins. There is no anal, or unpaired bottom, fin. The upper teeth are slender and have a single, narrow cusp, or point. The larger lower teeth are bladelike with a very high, single, broad cusp that may stand straight up or lean slightly toward the side. This shark also has moderately high, leaf-like dermal denticles, which are teethlike structures on the surface of the body. The broad, flat denticle crowns have three horizontal cusps coming off their edges. The only known specimen of Sherwood dogfish shark is 2.6 feet (80 centimeters) long and was found washed up onto a beach in New Zealand. Virtually nothing is known about their habits, biology or range. (See also Dogfish sharks.) |