Wiwaxia

Fatka, Oldřich, Kraft, Petr & Szabad, Michal, 2011, Shallow-Water Occurrence ofWiwaxiain the Middle Cambrian of the Barrandian Area, Czech Republic, Acta Palaeontologica Polonica 56 (4), pp. 871-875 : 873-874

Palaeoecology of Wiwaxia

Rowlan and Gangloff (1988: 129) expressed the indirect interpretation that Wiwaxia represents a mobile deposit feeder or herbivore. Dornbos et al. (2005: 63–64) supposed that Wiwaxia lived on a muddy substrate crawling along the sediment using muscular contractions while feeding on the surface of the substrate. This mode of life was dependent on a relatively firm Proterozoic−style soft substrate with seafloor microbial mats. They summarised, that Wiwaxia belongs to forms well−adapted to a non−actualistic environmental setting. Ivantsov et al. (2005a: 75, 81) classified Wiwaxia as grazer of bacterial scum on algal thali. Because of the supposed presence of radula in Odontogriphus , Wiwaxia , and Kimberella, Caron et al. (2006) considered all these genera to be probable grazers feeding on bacterial mats. Caron and Jackson (2008: 226) classify Wiwaxia as radula−bearing epifaunal vagile grazer feeding on the co−occurring macrobenthic cyanobacteria.

In the Buchava Formation Wiwaxia occurs in an exceptional association, which is very characteristic for the basal Cambrian clastic sequence. These rocks represent shallow water sediments deposited in the early phase of marine transgression. The general composition of the specific association dominated by filtrating brachiopods and filtrating trilobites associated with the common grazing molluscs in the well aerated environment in the photic zone seems to fit well with the proposed grazing life habit of Wiwaxia . As sclerites of Wiwaxia occur in direct association with fragments of graptolites only, this assemblage can

http://dx.doi.org/10.4202/app.2009.0052

Wiwaxia corrugata Wiwaxia cf. corrugata Wiwaxia taijiangensis Wiwaxia SP.

represent inhabitants of distinct environment restricted to shallow margin of the basin.

Acknowledgements. — Petr Budil (Czech Geological Survey, Prague, Czech Republic) is kindly acknowledged for providing research support, technical assistance, and access to the collection of the late Prof. Bedřich Bouček. This study was supported by a Grant from the Czech Science Foundation (Projects N o 205/06/0395 and 205/09/1521) and the MŠM 0021620855 . This contribution was presented on the 9th Paleontological Conference (Warszawa, 10–11 October 2008) that was organised by the Institute of Paleobiology of the Polish Academy of Sciences .