Hybodus
Encyclopedia
Hybodus is an extinct genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of once-common, widespread and long lived shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s, first appearing towards the end of the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

 period, and disappearing at the beginning of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

. During the Triassic, Jurassic, and Cretaceous periods the hybodonts were especially successful and could be found in shallow seas across the world. For reasons that are not fully understood, the hybodonts became extinct near the end of the Cretaceous period.
Hybodus species grew to about 2 metres (6.6 ft) in length, and are believed to have been opportunist predators. It was not very big, but had the classic streamlined shark shape, complete with two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

s that would have helped it steer with precision. The mouth was not large, and rather than ruthlessly hunt large prey, Hybodus, was capable of eating a wide range of foods. They had several distinct features that made them stand apart from other primitive sharks. Firstly, they had two different types of teeth, suggesting a wide diet. The sharper teeth would have been used to catch slippery prey, while the flatter teeth probably helped them crush shelled creatures. Secondly, they had a bony blade on their dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

 that probably served a defensive function. The males also possessed claspers, specialized organs that directly insert sperm into the female, and which are still present in modern sharks.

The first fossilized teeth from Hybodus were found in England around 1845. Since then teeth (and dorsal spines) have been recovered from around the world.

Species

  • Hybodus houtienensis
  • ?Hybodus butleri
  • ?Hybodus obtusus
  • ?Hybodus parvidens
  • ?Hybodus rajkovichi
  • ?Hybodus montanendis

In popular culture

Hybodus was featured in the third episode of the popular 1999 documentary
Documentary film
Documentary films constitute a broad category of nonfictional motion pictures intended to document some aspect of reality, primarily for the purposes of instruction or maintaining a historical record...

 series Walking with Dinosaurs
Walking with Dinosaurs
Walking with Dinosaurs is a six-part documentary television miniseries that was produced by BBC, narrated by Kenneth Branagh, and first aired in the United Kingdom, in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that...

, being attracted to the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 of an Ophthalmosaurus
Ophthalmosaurus
Ophthalmosaurus is an ichthyosaur of the Middle to Late Jurassic period , named for its extremely large eyes. It had a graceful 6 metre long dolphin-shaped body, and its almost toothless jaw was well adapted for catching squid...

 in labor
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...

. It was unidentified in this episode. Hybodus made its return in the 2003 spin-off Sea Monsters, it was shown feeding on a giant struggling Leedsichthys
Leedsichthys
Leedsichthys was a giant pachycormid that lived in the oceans of the Middle Jurassic period. The closest living relative of the pachycormids is the bowfin, Amia calva, but this is only very distantly related....

 with Metriorhynchus
Metriorhynchus
Metriorhynchus is an extinct genus of marine crocodyliform that lived in the oceans during the Middle to Late Jurassic. Metriorhynchus was named by the German palaeontologist Christian von Meyer in 1830. Metriorhynchus was a carnivore that spent much, if not all, its life out at sea...

. Hybodus name was heard by Nigel Marven
Nigel Marven
Nigel Marven is a British wildlife presenter, television producer, author, and ornithologist.-Career:Marven studied botany at Bristol University until the age of 22 when he left to begin his career at the BBC Natural History Unit in Bristol...

's voice when he saw a Hybodus shark attacking a Leedsichthys.


In 2004, the children's book "Jurassic Shark" by Deborah Diffily and colorfully illustrated by Karen Carr highlights a pregnant female Hybodus shark battling a Liopleurodon and hunting ichthyosaurs.

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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