Taphonomy concerns the transit of material from the biosphere to the lithosphere (Efremov 1940) and involves a huge array of biological and geological processes affecting the post-mortem history of organisms. The taphonomic agents, abrasion, bioerosion, fragmentation, and disarticulation, are examples of such processes. The term bioerosion was originally suggested by Neumann (1966) as an abbreviation of "biologic erosion" and has been used to describe every form of biologic penetration into hard substrates, i.e., lithic, skeletal, or woody (see Warme 1975; Ekdale et al. 1984; Bromley 1994). Bioerosion structures, especially borings, are in many cases associated with observational problems. Fractures of a bioeroded substrate reveal random sections through the borings and tend to confuse the observer (Ekdale et al. 1984). Accurate three-dimensional casts are therefore necessary for making detailed studies of bioerosion structures.
During the 1970s different methods were developed to cast recent and fossil bioerosion structures and also recent tracemakers. The frequently used Epon-812, which originally was developed by Mollenhauer (1964) for embedding plant and animal tissue, is no longer available, but possible replacements for Epon-812 have been introduced (e.g., Embed 812 see Mascorro and Kirby 1986, 1989, 1991). Using Epon-812, Frankel (1970) described a technique designed to embed recent microfauna occurring in unconsolidated sandy sediments. Golubic et al. (1970) applied Epon-812 (at 60°C for 40-72 hours) to cast recent tracemakers within their borings. Golubic et al. (1970) tested the use of Vestopal and Araldite with comparable results. The exact kind of Vestopal and Araldite was not given. Perkins and Halsey (1971) cast recent tracemakers, i.e., in situ endolithic fungi and algae, and made plastic-impregnated thin sections and etched slabs. Following Ginsburg et al. (1966), they impregnated unconsolidated sediments with polyester resin under vacuum and pressure. The used resin was Plaskon No. 0951 mixed with a promotor and a catalyst. Later Golubic et al. (1975) suggested a double embedding method (i.e., two infiltration phases, both requiring Araldite Durcupan no. 2) that allowed the tracemaker to be examined in situ within the cast of its boring. This method was modified by Golubic et al. (1978) and Golubic (1983) to cast fossil borings applying one infiltration phase with gradual replacement of acetone with polymerizing resin, Araldite. This is analogous to the embedding schedules suggested by Finck (1960) and Mollenhauer (1964). The infiltration phase was followed by acetone "boiling" in a sample chamber attached to an aspirator. The method by Golubic et al. (1978) and Golubic (1983) has been widely used (e.g., Vogel 1987; Vogel et al. 1987; Tavernier et al. 1992; Schmidt and Freiwald 1993; Glaub 1994).
All these methods require heating of the embedding medium, containing sample material, at about 60°C for at least 40 hours, mostly 48. In this paper we describe a simpler and less time-consuming method, excluding such aspects as pressure impregnation, gradual infiltration, and "boiling" acetone away. Our method is based on a two-component epoxy (Epofix), which originally was developed for the metallographic field. The method is especially suited for mounting samples that are sensitive to heat or pressure.