Old snails
The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.
The old snails or primal snails (Diotocardia or Archaeogastropoda) were an order of the Fore-gill snails (Prosobranchia) according to the system of Johannes Thiele (1925 ). According to Thiele, they were a side line of the other snails in terms of development , which still had a number of original features. The families belonging to this group still have double auricles , double gills and double excretory organs . They have very differently shaped shells which, unlike all other snails, often still have mother-of-pearl layers in the shell. The groups that were counted among the adult snails occur mainly in the sea , but also occur in fresh water or on land. Thiele counted the archaeogastropoda superfamilies Zeugobranchia (now invalid, contained the families Haliotidae , Pleurotomariidae , Bellerophontidae and Fissurellidae ), Patelloidea , Trochoidea , Neritoidea and Cocculinoidea .
The old snail taxon has now been recognized as a polyphyletic taxon and has been abandoned.
literature
- Philippe Bouchet, Jean-Pierre Rocroi: Classification and Nomenclator of Gastropod Families. In: Malacologia. 47, Ann Arbor 2005, ISSN 0076-2997 , archive.org , ConchBooks, ISBN 978-3-925919-72-5 , pp. 1–397.
- Victor Millard (Ed.): Classification of the Mollusca. A Classification of World Wide Mollusca. Rhine Road, South Africa 1997, ISBN 0-620-21261-6 , ( online PDF; 2.46 MB) , from olivirv.myspecies.info, accessed on February 25, 2017.
- Winston Ponder & David Lindberg : Towards a phylogeny of gastropod molluscs; an analysis using morphological characters. In: Zoological Journal of the Linnean Society. 119, London 1997, ISSN 0024-4082 , doi: 10.1111 / j.1096-3642.1997.tb00137.x , pp. 83-265.