What makes Lamniformes unique?
Lamniform sharks have unique teeth and intestines with a ring valve (with numerous, closely stacked turns). Thresher sharks have caudal fins about equal to the length of the body, and goblin, sand tiger, megamouth, and crocodile sharks have caudal fins with relatively small lower lobes.
What is the phylogeny of sharks?
Sharks are a diverse and ecologically important group, including some of the ocean’s largest predatory animals. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks.
When did Lamniformes evolve?
The fossil record of lamniforms dates back to the Early Cretaceous ∼140 million years ago (Mya), and indicates they were diverse during the mid and Late Cretaceous (21, 22).
How many Lamniformes are there?
There are 15 species in this order of sharks. The sharks in this order range in size from 2-10 feet.
What are the characteristics of Lamniformes?
All lamnids share the following characteristics:
- body heavy, spindle-shaped with conical snout and narrow tail stalk supported by stout lateral keels.
- long gill slits, extending about 2/3 the depth of the throat.
- mouth armed with teeth that are relatively few but large.
- second dorsal and anal fins small with pivoting bases.
What makes a Lamniformes?
Lamniformes, also known as mackerel sharks, are a diverse order of sharks. Members of this order have two dorsal fins, an anal fin, five gill slits, and a mouth that extends past their eyes. Some of the world’s most popular shark species belong to this order.
Are sharks monophyletic?
ABSTRACT-Chondrichthyans (sharks, rays and holocephalans) are subjected to cladistic analysis in order to identify possible monophyletic groups. It is concluded that elasmobranchs and chi- maeroids are monophyletic sister-groups, but that sharks are not monophyletic unless holocephalans are included.
Is a great white shark a mackerel?
Mackerel sharks, also called white sharks, are large, fast-swimming sharks, found in oceans worldwide. They include the great white, the mako, and porbeagle shark. Mackerel sharks have pointed snouts, spindle-shaped bodies, and gigantic gill openings.
Are Lamniformes endangered?
Not extinct
Mackerel sharks/Extinction status
Is dog fish a shark?
However, the dogfish is a member of the shark family and does provide a dependable catch on days when little else is biting, especially as dogfish feed just as well in bright sunlight as they do at night.
Do cartilaginous fishes have bony ancestors?
They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of bone tissue….Chondrichthyes.
| Cartilaginous fishes Temporal range: Late Silurian to Present | |
|---|---|
| Infraphylum: | Gnathostomata |
| Clade: | Eugnathostomata |
| Class: | Chondrichthyes Huxley, 1880 |
| Subclasses and orders |
How does a shark give birth?
Ovoviviparity: Most sharks are ovoviviparous; they combine the first two methods. They produce eggs, but instead of hatching outside the body as in oviparity, the eggs are carried within the female for the gestation period. When the egg hatches, the shark pup continues developing inside the female until it’s born.