The Ichnofacies Paradigm - Trace Fossils as Indicators of Sedimentary Environments - page 100

conditions at the bed, food resource types and availability, water turbidity, water
salinity, depositional rates, oxygenation, and temperature. These factors tend to
change in a proximal to distal trend, such thatmarine Seilacherian ichnofacies are
properly recognized to display only a passive relationship to bathymetry (e.g.,
Ekdale, 1988; Ekdale et al., 1984; Frey et al., 1990; F¨rsich, 1975 ). Much of
the ethological focus in marine ichnofacies is related to substrate consistency
and trophic style (e.g., the food-resource paradigm), although a wide range of
behavioral and trophic groupings can be identified. Continental ichnofacies
and their distributions, by contrast, are largely independent of such proximal-
distal bathymetric trends (with the exception of some lacustrine associations)
but instead reflect organism responses to different environmental factors (see
Buatois and M ´ ngano, 2011; Melchor et al., 2012 for summaries). For the con-
tinental realm, climate is an overriding control, closely linked to the availability
of water, either as surface water or as pore water ( Buatois and M ´ ngano, 1995;
Dubois et al., 2012; Genise et al., 2000; Hasiotis et al., 2007 ). In freshwater set-
tings, energy, oxygenation, and substrate consistency remain critical factors as
well. There is also a close association between vegetation patterns and terrestrial
ichnofacies ( Buatois and M ´ ngano, 2011; Genise et al., 2010 ), which is largely
dictated by climate (temperature and precipitation).
Many ichnofacies practitioners argue that the archetypal Seilacherian ichno-
facies are proper names. As the namesake is derived from an ichnogenus, it must
be capitalized and italicized. There is only one Skolithos Ichnofacies (that is, not
“a” Skolithos Ichnofacies), and so it is also a proper name, and the word “ich-
nofacies” must be capitalized when following the namesake identifier. Suites
and ichnofabrics are not formally defined and do not have broad temporal or
spatial recurrence—hence, they are not proper names. While the ichnogenus
or ichnogenera identifiers are capitalized and italicized, the words “suite” or
“ichnofabric” are not capitalized.
Seilacher (1967) defined the six original ichnofacies, each named for a char-
acteristic ichnotaxon. These correspond to four of the five softground marine
types ( Skolithos , Cruziana , Zoophycos , and Nereites )( Table 1 ), one of three
substrate-controlled types ( Glossifungites ), and one of the six softground
continental types ( Scoyenia )( Table 2 ). Frey and Seilacher (1980) added the
Trypanites Ichnofacies to characterize borings in hardgrounds, and Bromley
et al. (1984) introduced the Teredolites Ichnofacies to encompass borings
into woodgrounds. Frey and Pemberton (1987) proposed the Psilonichnus
Ichnofacies for permanent vertical to inclined dwellings, continental biogenic
structures, and surface locomotion traces in sand-prone substrates of high inter-
tidal and supratidal coastal settings. Historically, the dataset for this ichnofacies
has been somewhat sparse, largely owing to the setting's low preservation
potential. This has been alleviated more recently through the addition of
well-described case studies (e.g., Curran, 2007; Curran and White, 1991;
Marshall, 2003; Nesbitt and Campbell, 2006; Netto and Grangeiro, 2009 ).
Buatois and M´ngano (2011) have indicated that the Psilonichnus Ichnofacies