Pawson, David L Department of Invertebrate Zoology, Smithsonian Institution, Washington, DC.
- Additional Readings
An order of sea urchins (class Echinoidea) with a large elevated apical disc that covers about one half of the upper surface of the test. The center of the disc in Salenioida has one or more large suranal plates covering the anus, which is slightly posterior in position. Ambulacral plates are very small compared with the interambulacral plates, and the pore pairs for the tube feet are arranged in groups of one, two, or three. Each interambulacral plate has a single large primary tubercle, which is crenulate and may be perforate or imperforate. The lantern (feeding and locomotor apparatus) is of the stirodont type, with the apophyses not connected at the upper end, and with keeled teeth that are T-shaped in cross section. Some years ago, two families were recognized in the Salenioida: (1) Acrosaleniidae, which included approximately six fossil genera, ranging from the Upper Triassic or Lower Jurassic to the Cretaceous of Europe, Africa, Asia, and the Caribbean; and (2) Saleniidae, with about 10 genera, ranging from the Upper Jurassic to the Recent (two extant genera) in many parts of the world. The family name Acro saleniidae has been abandoned by several authors in favor of an informal grouping—the acrosaleniids. See also: Echinodermata; Echinoidea
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. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles 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 19,000 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