Smith, Andrew B. Department of Paleontology, Natural History Museum, London, United Kingdom.
Show previous versions
- Links to Primary Literature
- Additional Readings
A former primitive order of brittle stars (class Ophiuroidea) reassigned to the order Ophiurida. The order Oegophiurida is an invalid taxon of brittle stars. Formerly comprising a single living genus, Ophiocanops, the members of this former order have been incorporated into the order Ophiurida. In the oegophiurid brittle stars, the gonads, together with outpouches of the digestive system (gastric ceca), extend from the central body cavity into the arms. This is a characteristic shared with asteroids (class Asteroidea). The digestive system is confined to the disk in all other ophiuroids, and the gonads extend into the arms in only a small number of primitive taxa. In addition, although paired and firmly united, the vertebral ossicles that make up the arms are not fused distally, whereas left and right vertebral ossicles are always fused in other extant ophiuroids. The oegophiurid brittle stars also primitively lack radial and oral shields in their disk, as well as lacking ventral arm plates. See also: Asteroidea; Echinodermata; Ophiuroidea
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 42 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 17,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information