Respuesta :
snout pig-like, deep nasoral groove connecting nostrils to mouth corners prominent ridge above each eye; eyes without nictitating fold five pairs of gill slits, the last three above the pectoral fin base; spiracles tiny a stout spine on the forward margin of both dorsal fins presence of an anal fin (which serves to distinguish them from the spiny dogfishes, order Squaliformes) in adults, molar-like crushing teeth in rear of the jaws that are very different from the conical grasping teeth in front (hence the group's scientific name, which means "different teeth")oviparous; egg case auger-shaped, conical with two broad flanges spiraling from apex to base bottom-dwellers in shallow coastal waters (usually less than 300 feet or 100 metres); exclusively marine, inhabiting warm temperate and tropical parts of the western and eastern Pacific and western Indian oceansa single genus (Heterodontus) in the family Heterodontidae
