Sprinkle, James Department of Geological Sciences, University of Texas, Austin, Texas.
- Additional Readings
A small class of primitive echinoderms (subphylum Echinozoa) known from the single species Camptostroma roddyi based on about 200 specimens from the Early Cambrian (Bonnia-Olenellus Zone) in southeastern Pennsylvania. Camptostroma was originally described as a hydrozoan or jellyfish, but it was recognized as an echinoderm and the new class Camptostromatoidea was set up for it. Camptostroma has been reinterpreted as an early edrioasteroid, and as a “stem echinoderm” ancestral to several other groups including edrioasteroids. Because of Camptostroma's puzzling morphology, different reconstructions of it have been made (see illustration). It has a conical or domal theca or body with a nearly circular outline, divided into a pleated lower theca with larger and smaller overlapping plates, and a domed upper theca made up of large plates with pores on their margins surrounded by numerous smaller plates. The upper theca bears five straight to curved ambulacra protected by numerous cover plates and radiating from the central mouth, and a small anal pyramid at one edge. Camptostroma probably had the lower theca either embedded in the soft sediment or attached to objects lying on the sea floor, making it a stationary or attached, low-level suspension feeder using tube feet in the ambulacra to capture small food particles drifting by the theca. The unusual thecal plating is the main feature separating Camptostroma from later Edrioasteroidea, which it otherwise resembles, but this genus may also have been ancestral to other classes such as the Eocrinoidea. See also: Echinodermata; Echinozoa
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 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 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