Heteractinida
| Heteractinida | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Porifera |
| Informal group: | †"Heteractinida" Hinde, 1887 |
| Included groups | |
|
See text | |
| Synonyms | |
| |
The Heteractinids are a grade of sponges that are paraphyletic with respect to Hexactinellida.[1] Their distinctive trait is their six-pronged (snowflake-like) spicules, whose symmetry historically suggested a relationship with the triradial Calcarean sponges.[1] Nevertheless, they actually represent a polyphyletic grade, from which the hexactinellids arose.[1]
Families
The following families are placed in Heteractinida:[2]
- †Astraeospongiidae Miller, 1889
- †Eiffeliidae Rigby, 1986
- †Nuchidae Pickett, 2002
- †Wewokellidae King, 1943
References
- ^ a b c Botting, J. P.; Butterfield, N. J.; Valentine, J. W. (2005). "Reconstructing early sponge relationships by using the Burgess Shale fossil Eiffelia globosa, Walcott". Proceedings of the National Academy of Sciences of the United States of America. 102 (5): 1554–1559. doi:10.1073/pnas.0405867102. JSTOR 3374469. PMC 547825. PMID 15665105.
- ^ Pickett, J. (2002). "†Order Heteractinida Hinde, 1887". In Hooper, J.N.A.; Van Soest, R.W.M.; Willenz, P. (eds.). Systema Porifera: A Guide to the Classification of Sponges. Boston, MA: Springer. pp. 1121–1140. doi:10.1007/978-1-4615-0747-5_117. ISBN 978-0-306-47260-2.
 | This poriferan- (or sponge-) related article is a stub. You can help Wikipedia by expanding it. |