Environmental Engineering Reference
In-Depth Information
Chapter 3
Trace-Fossil Systematics
Dirk Knaust
1
Statoil ASA, Stavanger, Norway
1
Corresponding author: e-mail: dkna@statoil.com
1. INTRODUCTION
The application of trace-fossil studies to sedimentological investigations, particu-
larly the reconstruction of depositional environments, is largely dependent on the
exact recognition of ichnotaxa. The heterogeneous composition of many ichnogen-
era, with ichnospecies of similar morphology and size, but contrasting in behavior
and paleoecological requirements of their producers, inmany cases calls for an exact
determination of the ichnotaxa at the ichnospecies level. Unfortunately, the taxo-
nomical treatment of trace fossils is not straightforward and is far away from being
resolved (
Bertling, 2007
). Ichnotaxonomy, themanner inwhich to name and classify
trace fossils, has been the subject of many proposals and discussions (see
Miller,
2012; Rindsberg, 2012
), and regularly arranged workshops on special issues of ich-
notaxonomy have resulted in further guidelines toward a uniform approach in the
procedure of naming trace fossils (
Bertling et al., 2006; Rindsberg, 1990
).
Moreover, the lack of a consistent classification scheme for trace fossils often
hinders integrated studies in which ichnological information is fully employed
in sedimentological analysis. Our current basis for taxonomical and systematic
work of invertebrate trace fossils is the
Treatise on Invertebrate Paleontology,
Part W
, compiled in its second edition by
H¨ntzschel (1975)
, and listing ichno-
genera in alphabetical order. Before and after that milestone, there were several
attempts to classify trace fossils by using various criteria, such as their ethology
(
Chamberlain, 1971; de Gibert et al., 2004; Krejci-Graf, 1932
), supposed
producers (
Dzik, 2005, 2007; Lessertisseur, 1956; Vialov, 1968
), preservation
(
Martinsson, 1965, Seilacher, 1964
), overall morphology (
Ksi˛˙kiewicz,
1970, 1977; Richter, 1927; Simpson, 1975
), or a combination (
Seilacher,
1953; Zherikhin, 2003
).
Gong and Si (2002)
attempted to distinguish and
describe morphological characteristics of trace fossils by topological parameters
as the basis for the classification and evolution of metazoan traces. Furthermore,
Ekdale and Lamond (2003)
employed trace-fossil phenograms to depict evolu-
tionary relationships of behavioral components reflected in some common trace
fossils.
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