Rajiformes Temporal range: middle Eocene–Recent |
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Little skate (Raja erinacea) | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Superorder: | Batoidea |
Order: | Rajiformes L. S. Berg, 1940 |
Rajiformes is one of the four orders of batoids, flattened cartilaginous fishes related to sharks.
Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the body, and the gill slits on the underside. They have flattened, crushing teeth, and are generally carnivorous, although manta rays are filter feeders. Most species give birth to live young, although some lay eggs with a horny capsule ("mermaid's purse").
Classification
The following families are recognized:
- Family Anacanthobatidae (smooth skates)
- Family Rajidae (skates)
- Family Rhinidae (bowmouth guitarfishes)
- Family Rhinobatidae (guitarfishes)
- Family Rhynchobatidae (wedgefishes)
A fossil family is Rhombodontidae, from the Maastrichtian stage of the Cretaceous period of Europe, Asia, Africa and the Americas.[1]
References
- ^ http://www.elasmo.com/frameMe.html?file=genera/cretaceous/rhombodus.html&menu=bin/menu_genera-alt.html Rhombodus DAMES 1881 Extinct myliobatoid ray — Upper Cretaceous by Elasmo.com
- Froese, Rainer, and Daniel Pauly, eds. (2011). "Rajiformes" in FishBase. February 2011 version.
- Batoids: Sawfishes, Guitarfishes, Electric Rays, Skates, and Sting Rays
- J. D. McEachran, K. A. Dunn, T. Miyake (1996). "Interrelationships of the batoid fishes (Chondrichthyes: Batoidea)". In Interrelationships of Fishes, Academic Press.
- "Skate or Ray?". ReefQuest Centre for Shark Research. Accessed 20 March 2008.
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