Order Orchocladina Rauff, 1894next section
Family Anthaspidellidae Miller, 1889
Genus Fibrocoelia Van Kempen, 1978
Fibrocoelia tubantiensis Van Kempen, 1978
Discussion — Van Kempen (1978) established Fibrocoelia tubantiensis based on a single specimen from Early Pleistocene fluvial deposits in a sand- and gravel-pit near Kloosterhaar, the Netherlands. This type specimen was housed in the palaeontological collections of the Geological Institute of the Amsterdam University (registration number PA 8690). After the closing of the Institute, the specimen was temporarily in Van Kempen’s private collection. After his death in 2002, his collection moved to the (then) Nationaal Natuurhistorisch Museum, Leiden. However, the present author, acting as solicitor, noticed that a small number of registered sponges were missing. Some time ago, Mrs. Van Kempen re-discovered a box, containing among others the actual holotype. The specimen is now reposited in the collections of the Netherlands Centre for Biodiversity – Naturalis, Leiden, registered as RGM 550 579.
An unnumbered specimen of Fibrocoelia tubantiensis from Pliocene fluvial deposits on the Island of Sylt, northwestern Germany, appeared to be in the same box. It had been donated by the late Ulrich von Hacht of Hamburg, apparently after the publication of Fibrocoelia in 1978, because the latter specimen was not described by Van Kempen. The scarcity of material warrants a repository in the same collections as where the holotype is housed, registered as RGM 550 580.
Family Astylospongiidae von Zittel, 1877
Genus Syltrochos Von Hacht, 1981
Syltrochos pyramidoidalis Von Hacht, 1981
Discussion — Specimens of Syltrochos pyramidoidalis Von Hacht, 1981, were, until recently, known exclusively as erratics (Rhebergen, 2009). Their age was established based upon co-occurring guide fossils, such as trilobites and brachiopods (Krueger, 1990), which indicate the Baltic regional Jöhvi Substage (D1 ) to Keila Stage (D2 ). As a result of intensive silicification, spicules were dissolved by chalcedony, skeletal structures devistated and only the canal system was recognisable. As a result, Finks & Rigby (2004) assigned Syltrochos as an endemic genus in open nomenclature to uncertain order and family. However, new material from the Dutch-German border region revealed the skeleton to be composed of spheroclones. On account of this characteristic, Syltrochos pyramidoidalis Von Hacht, 1981, has to be assigned to the family Astylospongiidae von Zittel, 1877.
Genus Carpospongia Rauff, 1893
Carpospongia langei Von Hacht, 1994
Discussion – Von Hacht (1994) established the astylospongiid species Carpospongia langei, in order to distinguish globular sponges with extremely long tubercles from Carpospongia castanea (Roemer, 1861). Recently, the present author studied a sponge assemblage in the collections of the VSEGEI in St. Petersburg (Russia). The material had been collected from the Shundorovo Formation, which is exposed in a quarry southwest of St. Petersburg (Iskyul & Fedkovets, 2008). It is coeval with the upper part of the Estonian Idavere Substage (C3 ), and possibly with a part of the lavender-blue silicifications in Germany and the Netherlands, which is associated with the Lausitz-Sylt sponge assemblage.
A number of specimens appeared to be identical to C. langei, but were labelled Carpospongia pogrebowi Asatkin, 1949. The assemblage was very similar to the astylospongiid part of the erratic Lausitz-Sylt sponge assemblage mentioned above. Asatkin had collected sponges from about the same outcrop during the 1920s. In his first paper on this subject, Asatkin (1931) described the sponge as Carpospongia sp. In his posthumously published chapter in the Russian Atlas (Asatkin, 1949), he described it as the new species C. pogrebowi.
Unfortunately, his publications remained unnoticed in the European and American literature (Rhebergen, 2009). They are of such importance that they will be subject of a future paper, because they deal with the first sponge association from bedrock from Baltica to be recorded, including the oldest astylospongiids worldwide (Mehl-Janussen, 1999). Then, the coeval Russian, Estonian and erratic sponge associations will be compared extensively. At present, I confine myself to the conclusion that, on account of priority, the name Carpospongia langei Von Hacht, 1994, is invalid, being a junior synonym of Carpospongia pogrebowi Asatkin, 1949.