Helcionelloida
| Helcionelloida Temporal range:
| |
|---|---|
| |
| Latouchella costata | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Subphylum: | Conchifera |
| Class: | †Helcionelloida Peel, 1991 |
| Orders | |
and see text | |
Yochelcionella cyrano
Helcionelloida is an extinct group of ancient molluscs (phylum
Mollusca). These are the oldest known conchiferan molluscs, that is, they had a mineralised shell. Some members of this class were mistaken for Monoplacophorans. The class was erected by Peel in 1991.[1]
Anatomy
These animals were
snorkel
"-like opening which was most likely used for breathing.
2005 taxonomy
The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005[2] categorizes members of this taxon within the Paleozoic molluscs of uncertain systematic position, but that taxonomy to not use the name Helcionelloida.
2006-2007 taxonomy
Taxonomy of helcionelloid according to the opinion of P. Yu. Parkhaev:[3][4]
Gastropoda Cuvier, 1797
Subclass Archaeobranchia Parkhaev, 2001
- Order HelcionelliformesGolikov & Starobogatov, 1975
- Superfamily Helcionelloidea Wenz, 1938
- Family HelcionellidaeWenz, 1938
- Family IgarkiellidaeParkhaev, 2001
- Family Coreospiridae Knight, 1947
- Family
- Superfamily Yochelcionelloidea Runnegar & Jell, 1976
- Family TrenellidaeParkhaev, 2001
- Family YochelcionellidaeRunnegar & Jell, 1976
- Family Stenothecidae Runnegar & Jell, 1980
- Subfamily Stenothecinae Runnegar & Jell, 1980
- Subfamily Watsonellinae Parkhaev, 2001
- Family
- Order Pelagiellifomes MacKinnon, 1985
- Family Pelagiellidae Knight, 1952
- Family Aldanellidae Linsley et Kier, 1984
Subclass Divasibranchia Minichev & Starobogatov, 1975
- Order KhairkhaniiformesParkhaev, 2001
- Family Khairkhaniidae Missarzhevsky, 1989
Subclass Dextrobranchia Minichev & Starobogatov, 1975
- Order OnychochiliformesMinichev & Starobogatov, 1975
- Family Onychochilidae Koken, 1925
References
- ISBN 978-0-521-40242-2.
- ISBN 3-925919-72-4. ISSN 0076-2997. 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278
- ^ P. Yu. Parkhaev (2006) "Adaptive radiation of the Cambrian helcionelloid mollusks (Gastropoda, Archaeobranchia). Archived 2015-06-10 at the Wayback Machine" In: S.V. Rozhnov (ed.) "Evolution of the biosphere and biodiversity. Towards the 70th anniversary of A. Y. Rozanov". 2006. Moscow, pp. 282-296.
- doi:10.1144/SP286.31.
External links
- Atkins C. J. & Peel J. S. (2008). "Yochelcionella (Mollusca, Helcionelloida) from the lower Cambrian of North America". . - slightly different taxonomic placement of Yochelcionellidae.
- https://web.archive.org/web/20080930105735/http://www.palaeos.com/Invertebrates/Molluscs/BasalMollusca/Conchifera/Helcionelloida.html