Hexanchiformes - Wikipedia
The Hexanchiformes / h ɛ k ˈ s æ ŋ k ɪ f ɔːr m iː z / are a primitive order of sharks, [a] numbering just seven extant species in two families. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens.
Hexanchiformes: Cow Sharks
The hexanchiform sharks are mysterious creatures that lead secret lives, often in the deepest, darkest, coldest parts of the ocean. Due to the inaccessible depths inhabited by these sharks, we know very little about them.
What Are Cow Sharks (Or Hexanchiformes)? - sharksinfo.com
Going back to prehistoric times, the Cow sharks have been considered the ancient group of sharks belonging to an order Hexanchiformes. The fossil records of Cow sharks depicted that the specimen is somehow related to the modern-day Seven-gill sharks.
Cow shark - Wikipedia
Cow sharks are a shark family, the Hexanchidae, characterized by an additional pair or pairs of gill slits. Its 37 species are placed within the 10 genera: Gladioserratus, Heptranchias, Hexanchus, Notidanodon, Notorynchus, Pachyhexanchus, Paraheptranchias, Pseudonotidanus, Welcommia, and Weltonia. [2]
Hexanchiformes (Six- and Sevengill Sharks) | Encyclopedia.com
Hexanchiforms are an ancient lineage, as well-documented fossil skeletons of Notidanoides muensteri date from the late Jurassic (some 150 million years ago, or mya) Solnhofen limestones of southern Germany. Notidanoides was a large shark, up to 9.8 ft (3 m) in length, with features suggestive of modern hexanchiforms, such as a single dorsal fin.
Hexanchiformes - Animalia
The Hexanchiformes are a primitive order of sharks, that numbering just seven extant species in two families. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens. Species are widespread and found across most of the world.
Cow Shark - American Oceans
Cow sharks, also known as Hexanchiformes, are a group of sharks that are characterized by having six or seven gill slits on the sides of their bodies, which is more than most other shark species. There are several types of cow sharks, each …
Hexanchiformes - an overview | ScienceDirect Topics
The Hexanchiformes (Cow and Frilled Sharks) comprises two families, four genera, and seven species of morphologically distinct sharks, in that they are the only group to possess six or seven paired gill slits, a single dorsal fin, and an anal fin. Members of this group of moderately sized to very large sharks mostly occupy a benthopelagic habitat.
Evolutionary Relations of Hexanchiformes Deep-Sea Sharks …
2013年9月5日 · In this study, we determined the whole mitochondrial DNA (mtDNA) sequences of seven sharks including representatives of the five Hexanchiformes, one squaliform, and one carcharhiniform and inferred the phylogenetic relationships among those species and 12 other Chondrichthyes (cartilaginous fishes) species for which the complete mitogenome is av...
Hexanchiformes – Frilled & cow sharks - BioDB
They are often considered the most primitive type of shark, showcasing features that offer a glimpse into their ancient origins. One distinctive characteristic is the presence of a single dorsal fin, a trait harkening back to their ancient lineage.