Eogastropoda

Common limpet ( Patella vulgata ')

The Eogastropoda are a large group of snails, which is now usually regarded as a subclass. To her the taxa are provided, which are commonly referred to as " True limpets " Patellogastropoda and the extinct Euomphalida and possibly the Neomphalida. Compared to the other sub- class Orthogastropoda is the much smaller portion of the types of the screw.

History

Ponder and Lindberg (1997 ) showed that the previous large group Prosobranchia is paraphyletic within the auger. According to the rules of cladistics a paraphyletic group must be dissolved and split into monophyletic groups. After the cladistic analysis of Ponder and Lindberg 1997, the snails can therefore divided into two major groups, the Orthogastropoda and the ' Eogastropoda '. They may be treated in linneisch hierarchical sense as subclasses. The Orthogastropoda include part of the so-called Prosobranchia and Opisthobranchia and Pulmonata the. The subclass of Eogastropoda also contains some taxa that had previously been assigned to the Prosobranchia, but also the groups that can be called a " True limpets " ( Patellogastropoda ). In addition, some extinct groups are expected to Eogastropoda.

Definition

The Eogastropoda or Patellogastropoda are characterized by Ponder & Lindberg (1997) by the following apomorphic features. The features are in the fossil groups usually undetectable.

  • The rear housing is greater than the extension of front or side of the housing extension
  • The protoconch is deducted from Juvenilgehäuse
  • The shell has a foliate microstructure on
  • Blood vessels run through the shell muscles
  • No Propodium in the adult stage
  • Simple kidney on the right side of the pericardium
  • Pine from two to praise, which are fused dorsal
  • The number of tooth-bearing cartilage ( the radula ) are reduced from 3 or more pairs of two pairs
  • Nervous system: Fußknoten around the foot positioned a few compounds
  • Statozysten dorsal (or slightly to the rear) on the Fußganglien.

System

In the system of the recent snails Eogastropoda and Patellogastropoda largely correspond. The Eogastropoda only in that they also include the extinct order Euomphalida with differ.

  • Subclass Eogastropoda Order † Euomphalida de Koninck, 1881 Superfamily † Euomphaloidea White, 1877
  • Superfamily † Macluritoidea Carpenter, 1861
  • Superfamily † Clisospiroidea Miller, 1889
  • Superfamily † Loxonematoidea Koken, 1889
  • Superfamily † Ophiletoidea Koken, 1907
  • Superfamily † Straparollinoidea Wagner, 2002
  • Superfamily † Trochonematoidea Zittel, 1895
  • Superfamily Patelloidea Rafinesque, 1815
  • Superfamily Nacelloidea Thiele, 1891
  • Superfamily Lottiodea Gray, 1840
  • Superfamily Neolepetoidea McLean, 1990

The order Neomphalida McLean, 1981 is also provided by some authors to the Eogastropoda. Bouchet and Rocroi (2005) lead the group on the other hand, as a family under the Vetigastropoda.

David R. Lindberg Laurent-Guillaume de Koninck
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