Microbioerosion - Trace Fossils as Indicators of Sedimentary Environments - page 217

A B

10 m m 10 m m

C D

30 m m 30 m m

E F

30 m m 30 m m

FIGURE 6 SEM images of casted microborings produced by fungi. (A) Saccomorpha clava , Pleis-
tocene, Rhodes, Greece. (B) Saccomorpha sphaerula , Eocene, Paris Basin, Villiers-St.-Fr´deric,
France (courtesy of Gudrun Radtke). (C) Saccomorpha cf. terminalis , recent, Kosterfjord, Sweden,
85 m water depth. (D) Polyactina araneola , recent, Kosterfjord, Sweden, 50 m water depth.
(E) Orthogonum fusiferum , recent, Kosterfjord, Sweden, 1 m water depth. (F) Flagrichnus
profundus , recent, Faial, Azores, 150 m water depth.

and Flagrichnus baiulus ( Fig. 7 B), is not known to date but is likely to be found
among the fungi ( Glaub, 1994; Wisshak and Porter, 2006 ).
Apart from the ubiquitous cyanobacteria, also other (Eu)bacteria and Archaea
are likely involved directly in the degradation of calcareous substrates ( Friedman
et al., 1971 ) and indirectly through the related process of maceration ( Freiwald,
1995, 1998 ). Bacteria, for instance, are responsible for the karstification of limestone
bedrock ( Golubic and Schneider, 1979 ) and are an important catalyst in speleogen-
esis ( Barton and Jurado, 2007 ). However, they are difficult to address, owing to their
minute size, but advances are made via molecular methods. To date, only two ich-
notaxa have been tentatively related to the activity of bioeroding bacteria ( Budd and
Perkins, 1980; Radtke, 1991 ), Scolecia serrata ( Fig. 7 C), and Scolecia maeandria ,
the former being already known from Carboniferous strata ( Wisshak et al., 2008 ).