Deep-Sea Fans - Trace Fossils as Indicators of Sedimentary Environments - page 625

that respond to short-term environmental fluctuations. There are, however,
more guesses than proofs in this matter (for a discussion, see Miller, 2007 ).
Numerous studies on deep-sea trace fossils with significant systematic des-
criptions are available, not only for the Paleozoic, for instance by Delgado
(1910) , Pfeiffer (1968) , Osgood (1970) , Chamberlain (1971) , Pickerill
(1980) , Benton (1982a) , Stepanek and Geyer (1989) , Fillion and Pickerill
(1990) , Crimes and Crossley (1991) , McCann (1993) , Orr (1995, 1996) , and
references therein, Orr et al. (1996) ; but also for the Mesozoic and Cenozoic,
for instance by Sacco (1888) , Squinabol (1890) , Azpeitia Moros (1933) , Crimes
(1973, 1977) , Ksi˛˙kiewicz (1977) , Crimes et al. (1981) , McCann and Pickerill
(1988) , Leszczy ´ ski and Seilacher (1991) , Miller (1991a, 1993) , Uchman
(1995a, 1998, 1999, 2001) , Buatois et al. (2001) , and references therein.

3. PRE-DEPOSITIONAL TRACE FOSSILS
Most of the pre-depositional forms are represented by graphoglyptids, which are
preserved often as semi-reliefs resulting from the scouring and casting of shallow
burrow systems; most of them are interpreted as agrichnia. They are common,
but never abundant on the soles of sandy turbidites. The tubes are commonly less
than 2 mm wide. For a discussion of graphoglyptids, the reader is referred to
Seilacher (1977a, 2007) , Miller (1991b) , and Uchman (1995a, 1998, 2003) .
Cosmorhaphe ( Fig. 1 A) is a hypichnial, semicircular ridge forming first- and
second-order, regular meanders.
Helminthorhaphe ( Fig. 1 B) is a hypichnial, semicircular ridge forming only
first-order, regular, high-amplitude meanders.
Lorenzinia ( Fig. 1 C) is a hypichnial structure composed of semicircular bars
and knobs radially arranged around a central empty area.
Megagrapton ( Fig. 1 D) is composed of hypichnial semicircular ridges,
forming an irregular net.
Paleodictyon ( Fig. 1 H) is composed of hypichnial semicircular ridges
forming a regular hexagonal net. The meshes of the net are usually 1 to 35,
exceptionally up to 140 mm wide.
Spirorhaphe ( Fig. 1 F) is a hypichnial semicircular ridge forming a spiral
with a loop in the centre.
Spirophycus ( Fig. 1 G) is a horizontal ridge bent at one end in a spiral. This
non-graphoglyptid trace fossil is probably a preservational variant of Nereites ,
while scoured and cast. For further details, see Ksi˛˙kiewicz (1977) and
Uchman (1998) .
Scolicia strozzii ( Taphrhelminthopsis ; Fig. 1 E) is a bilobate hypichnial

smooth ridge with a central furrow. At least in Late Jurassic and younger
sediments, it is interpreted as a washed-out and cast shallow irregular echinoid
burrow ( Uchman, 1995a ).

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