Carlson, Sandra J. Department of Geology, University of California, Davis, California.
Last reviewed:January 2020
- Related Primary Literature
- Additional Reading
Formerly, one of the two classes of the phylum Brachiopoda. The phylum comprises solitary, exclusively marine, coelomate [having a true coelom or mesodermally lined body cavity], lophophorate [having a lophophore, a food-gathering ciliated organ], bivalved animals, with the two valves symmetrical about a median longitudinal plane. Now the former Inarticulata comprises two of the three subphyla currently recognized, Linguliformea and Craniiformea, together with a few taxa considered to be basal rhynchonelliform brachiopods. These two subphyla encompass approximately 6% of the generic diversity of the Recent (Holocene, from 10,000 years ago to the present day) and fossil brachiopods. The name Inarticulata refers to the lack of tooth-and-socket articulatory structures on the two valves of these brachiopods. The name was abandoned because of recent changes made in the classification thought to reflect a better understanding of phylogenetic relationships among several groups of Cambrian brachiopods. Because some linguliform and craniiform species have primitive forms of articulation that may or may not be homologous with articulated brachiopods, and because some early rhynchonelliforms lack articulation, the term Inarticulata no longer accurately characterizes this group of brachiopods. However, molecular and morphological evidence suggests that Linguliformea and Craniiformea are each likely to be monophyletic (evolved from a single interbreeding population), are sister groups to one another, and may form a clade, together with Phoronida at the base, that is the sister group to Rhynchonelliformea. See also: Brachiopoda; Phoronida; Rhynchonelliformea
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