Cycloneritimorpha

Cycloneritimorpha
Family Neritidae: Nerita plicata on intertidal rock surfaces at Turtle Island, Fiji
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Neritimorpha
(unranked):	clade Cycloneritimorpha Frýda, 1998[1]
Families
See text

Cycloneritimorpha (nerites and false-limpets^[2]) is a clade of land snails, freshwater snails, and sea snails. These are gastropod molluscs within the larger clade Neritimorpha. 14 of the families in the clade are still extant, and 8 of the families are extinct.

According to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), as well as the Cycloneritimorpha, the clade Neritimorpha also contains the (entirely fossil) clade Cyrtoneritimorpha, plus a number of other fossil families that are currently unassigned.

The earliest evolutionary forms of Cycloneritimorpha show double visceral organs, double gills, and normally a double-chambered heart.^[3]

Taxonomy

The taxonomy of Cycloneritimorpha is based on work by Kano et al. (2002)^[4], that recognizes 4 clades. These clades are established on genetic analysis (28S rRNA) of recent species only. These clades proposed by Kano are ranked as superfamilies in taxonomy of the Gastropoda (Bouchet & Rocroi, 2005).

Clade Cycloneritimorpha contains:

• Superfamily Helicinoidea
  • Family Helicinidae
  • † Family Dawsonellidae
  • † Family Deaniridae
  • Family Neritiliidae
  • Family Proserpinellidae
  • Family Proserpinidae
• Superfamily Hydrocenoidea
  • Family Hydrocenidae
• Superfamily Neritoidea
  • Family Neritidae
  • Family Phenacolepadidae
  • † Family Pileolidae
• Superfamily Neritopsoidea
  • Family Neritopsidae
  • † Family Cortinellidae
  • † Family Delphinulopsidae
  • † Family Plagiothyridae
  • † Family Pseudorthonychiidae
  • Family Titiscaniidae
• Superfamily Symmetrocapuloidea
  • † Family Symmetrocapulidae

References

1. ^ http://wwmcat.it/malaco/photos/gastropoda/PF_GASTROPODA.htm
2. ^ http://molluscsoftasmania.net/Order%20pages/Neritimorpha%20-%20Cycloneritimorpha.html
3. ^ http://www.discoverlife.org/mp/20o?search=Gastropoda
4. ^ Kano Y., Chiba S. & Kase T. 2002. Major adaptive radiation in neritopsine gastropods estimated from 28S rRNA sequences and fossil records. Proceedings of the Royal Society of London, B, 269: 2457-2465.