Carpet sharks are sharks classified in the order Orectolobiformes. Sometimes the common name "carpet shark" is used interchangeably with "wobbegong", which is the common name of sharks in the family Orectolobidae. Carpet sharks have five gill slits, two spineless dorsal fins, and a small mouth that does not extend past the eyes. Many species have barbels.
Carpet shark
Full body fossil of the Jurassic genus Phorcynis
Image: Blindshark
Image: Nurse shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha and are the sister group to the Batoidea. Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as Cladoselache and Doliodus first appeared in the Devonian Period, though some fossilized chondrichthyan-like scales are as old as the Late Ordovician. The oldest confirmed modern sharks (selachimorphs) are known from the Early Jurassic, about 200 million years ago, though records of true sharks may extend back as far as the Permian.
Shark
Fossil shark tooth (size over 9 cm or 3.5 inches) with crown, shoulder, root and root lobe
A collection of Cretaceous shark teeth
Shark fossil, Lebachacanthus senckenbergianus, at Permian period