An unusual Silurian erratic astylospongiid (Porifera) from Gotland, Sweden

A new Silurian (Llandovery, Telychian) sponge assemblage from Gotland, Sweden

“…The relatively frequent occurrence of cushion-to dome-shaped specimens of Multistella leipnitzae n. sp. from a restricted area near Lickershamn is remarkable, as is the absence of Caryoconus Rhebergen & van Kempen, 2002 at that location. This indicates at least some local variation in community ecology and localized transport from slightly different source areas.…”

“…However, when Rhebergen & van Kempen (2002) referred one species that occurred exclusively on Gotland to the new genus Caryoconus, its age was found to be Early Silurian (Llandovery to Wenlock) based on acritarchs in adhering sediment. Unfortunately, one of the samples in the first series of three had been contaminated with acritarchs from a previous sample, from younger strata exposed on Gotland (Zwier Smeenk, personal communication 2007).…”

“…However, there is no indication that he considered any of those sponges to be of 'Upper Silurian' age. Rhebergen & van Kempen (2002) summarized a discussion between Lindstr€ om, Schmidt (1891) and Stolley (Stolley 1900(Stolley , 1929 on the age and lithostratigraphical origin of the sponges. Lindstr€ om probably intended to describe at least part of the sponge assemblage, because he had drawings made by Lilljeval, but did not complete the work (Rhebergen 2007).…”

“…Additional specimens of identical or similar aberrant forms, collected by Mrs. Heilwig Leipnitz, Uelzen (Germany), led to further investigation of the collections of the Swedish Museum of Natural History (Rhebergen & von Hacht 2000). Rhebergen & van Kempen (2002) established the genus Caryoconus, by then dated as Early Silurian (Llandovery to Wenlock), as discussed below. Rhebergen (2005) also described some sponge taxa from Silurian strata exposed on Gotland, varying in age from the Lower Visby Formation (Llandovery) to the Eke Formation (Ludlow).…”

Chapter 8 Cambrian, Ordovician and Silurian non-stromatoporoid Porifera

“…De Freitas 1987, 1989, 1991Rigby & Chatterton 1989), although lithistids are also known from the Baltic (e.g. van Kempen 1983;Rhebergen & van Kempen 2002) and elsewhere. There are very few lithistids known from Avalonia, although some unstudied specimens from the Wenlock Limestone Formation exist in UK museum collections and one specimen from Ludlow siltstones of Shucknall Hill, Herefordshire in Hereford Museum (J. P. Botting pers.…”