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All vertebrate jaws, including the human jaw, evolved from early fish jaws. The appearance of the early vertebrate jaw has been described as "perhaps the most profound and radical evolutionary step in the vertebrate history". [4] [5] Fish without jaws had more difficulty surviving than fish with jaws, and most jawless fish became extinct.
Helicoprion is an extinct genus of shark-like [1] eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown.
The tiger shark is the only species in its family that is ovoviviparous; its eggs hatch internally and the young are born live when fully developed. [7] Tiger Sharks are unique among all sharks in the fact that they employ embrytrophy to nourish their young inside the womb. The young gestate in sacks which are filled with a fluid that nourishes ...
Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish, with some species reaching lengths of about 7–7.6 m (23–25 ft). [1]
Once it reaches a small shrimp or fish, it unhinges its enormous jaw to impale the creature and trap it inside its mouth. When it has caught its prey, it shuts its mouth and the little fish stays ...
Otodus megalodon fossil shark jaw (reconstruction) (late Cenozoic) 2. A commonly referred to transition is the evolution of Isurus hastalis, the extinct giant mako, into the great white shark, Carcharodon carcharias. There exist teeth that are believed to represent the transition between the two species.
Wobbegong is the common name given to the 12 species of carpet sharks in the family Orectolobidae.They are found in shallow temperate and tropical waters of the western Pacific Ocean and eastern Indian Ocean, chiefly around Australia and Indonesia, although one species (the Japanese wobbegong, Orectolobus japonicus) occurs as far north as Japan.
The smalltooth sand tiger or bumpytail ragged-tooth (Odontaspis ferox) is a species of mackerel shark in the family Odontaspididae, with a patchy but worldwide distribution in tropical and warm temperate waters. They usually inhabit deepwater rocky habitats, though they are occasionally encountered in shallow water, and have been known to ...