Sprinkle, James Department of Geological Sciences, University of Texas, Austin, Texas.
Last reviewed:January 2020
- Phylogeny and morphology
- Related Primary Literature
- Additional Reading
Enigmatic extinct echinoderms whose members are characterized by a flattened body form and the complete lack of pentameral (five-sided radial) symmetry. Previously considered the fifth subphylum of echinoderms, homalozoans (commonly called carpoids) originally included four extinct classes of early echinoderms that had a theca or body protected by calcite plates showing diagnostic stereom (a unique skeletal microstructure resembling a network or mesh of interconnected holes). About 92 homalozoan genera have been described, assigned to the following classes: Stylophora (also called Calcichordata), including the two orders Cornuta (Middle Cambrian–Late Ordovician) and Mitrata (Early Ordovician–Early Pennsylvanian), with a total of about 66 genera; Soluta (also called Homoiostelea; Middle Cambrian–Early Devonian), with 12 genera; Cincta (also called Homostelea; Middle Cambrian), with 11 genera; and Ctenocystoidea (Middle Cambrian), with three genera. See also: Echinodermata
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 10,000 highly qualified scientists and 46 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