Placocoeniidae

Duncan, 1884, p. 108

Placocoeniidae Duncan, 1884, p. 108 is a unavailable name.

This taxon represents a nomen dubium.

Remarks

Recently, the genus-group Placocoenioida Duncan, 1884, was introduced as "Family Placocoeniidae Duncan, 1884” (Löser, 2012). As clearly stated by Duncan (1884), he based his taxonomic framework on the descriptions provided by Milne Edwards (1860). However, on page 108 he describes the genus Placocoenia as having "…..Septa entire……Columella lamellar and well developed, or in three papillae…." The latter feature ("entire septa") he also mentions as one of the defining characteristics of his Alliance Placocoenioida. However, because the type species of the genus Placocoenia (=P. macrophthalma [Goldfuss, 1826]) has neither a columella that consists of papillae nor has it entire septa, Duncan’s Alliance differs from both the characteristics seen in the type species of the genus Placocoenia and the description of it provided by Milne Edwards (1860). Therefore, a family based on Duncan's Alliance Placocoenioida, cannot be considered synonymous with the Family Placocoeniidae Alloiteau, 1952, p. 626. Furthermore, the taxonomic position of the Alliance Placocoenioida remains unclear because based on the information provided by Duncan (1884, p. 108) it could belong to different families such as the family Columastreidae or the family Meandrinidae. These families contain taxa that generally have very minutely dentate septa which, however, may or may not be interpreted as being "entire". Therefore, the taxonomic position of Duncan's alliance cannot be clarified.

This page has been in preparation since 26-Feb-2014 16:40

This version was contributed by Rosemarie Baron-Szabo on 07-Jun-2017 13:59.

Page authors are: Rosemarie Baron-Szabo. Please contact the editor if you would like to contribute to the diagnosis of this taxon.

The editor is: Rosemarie Baron-Szabo