Glacial Environments - Trace Fossils as Indicators of Sedimentary Environments - page 297

presence of two pervasive ichnocoenoses, one dominated by arthropod
trackways, and another by non-specialized trails and shallow horizontal bur-
rows, well preserved in broad, shallow glacial basins. The arthropod
trackway-dominated ichnocoenosis is the most common in the fossil record,
being attributed to the activity of merostomes, isopod crustaceans, and aptery-
gote insects ( Fig. 1 ). A third ichnocoenosis, dominated by fish trace fossils, is
well preserved in deep, narrow Pleistocene glacial lake basins (see Supplemen-
tary Table 1 in http://booksite.elsevier.com/9780444538130 ).
In glacial Gondwana deposits, trackways include ichnospecies of Maculichna ,
Umfolozia ,and Protichnites (the last being less common; Fig. 1 A-C), but Kouph-
ichnium isp. and Orchesteropus atavus ( Fig. 1 D and G) also occur in the Falkland
and Paganzo basins, respectively, as well as Broomichnium permianum (formerly
Quadrispinichnia parvia ;see Benner et al., 2008 for further discussion) in the Karoo
Basin (see Supplementary Table 1 in http://booksite.elsevier.com/9780444538130 ) .
Crustacean resting traces are more rare, being represented by Gluckstadtella cooperi
in the Paran ´ andKaroo basins ( Fig. 1 E and F), and by Kingella natalensis , exclusive
to the Karoo Basin until now. Insect resting traces are represented by Tonganoxich-
nus isp. ( Fig. 1 I), recorded in the Paran ´ Basin. A particular suite composed exclu-
sively of myriapod trackways ( Diplichnites gouldi ) and trails ( Diplopodichnus
biformis ) also occurs in the Paran´ Basin ( Fig. 1 A, H, and J), being the most conspic-
uous trace-fossil assemblage in thin-bedded rhythmites of the Paran´ Basin
( Balistieri et al., 2002, 2003; Buatois et al., 2006, 2010 ; Nogueira and Netto,
2001 ;see Netto et al., 2009 for further discussion). Bilobate trace fossils, such as
Cruziana and Rusophycus , may be locally dominant ( Schatz et al., 2011a ). The
Pleistocene glacial trackway assemblage includes Glaciichnium liebegastensis
and Warvichnium ulbrichi as dominant ichnotaxa, but Steinsfjordichnus isp., Lusa-
tichnium slavensis , Irichnus isp., and other arthropod trackways also occur (see Uch-
man et al., 2008, 2009 and references therein; Supplementary Table 1 in http://
booksite.elsevier.com/9780444538130 ; Fig. 2 ).
The non-specialized trails and shallow burrows ichnocoenosis is composed
chiefly of Cochlichnus , Gordia , Helminthoidichnites , and Mermia (

Gordia
carickensis in Pleistocene records) ichnospecies in both Late Paleozoic Gond-
wana and Quaternary ice-age deposits (Supplementary Table 1 in http://book
site.elsevier.com/9780444538130 ) . This ichnocoenosis seems have been more
diverse in the Gondwana record, in which Helminthopsis and slightly deeper-
tier burrows of deposit feeders ( Hormosiroidea meandrica , Treptichnus pollardi ,
Treptichnus isp., Planolites isp.) and, very rarely, suspension feeders
( Palaeophycus isp.) also occur (Supplementary Table 1 in http://booksite.
elsevier.com/9780444538130 ; Fig. 3 A, D-F, I, and J). Accessory components,
including arthropod locomotion ( Cruziana problematica , Glaciichnium isp.),
and resting traces ( Rusophycus isp., R. carbonarius ), molluscan-type trails and
burrows ( Archaeonassa and Didymaulichnus , the latter which can also be pro-
duced by arthropods, Lockeia and Protovirgularia ichnospecies), non-special-
ized vertical burrows ( Arenicolites isp., Diplocraterion isp., Skolithos isp.),
and fish trails ( Undichna isp.), have also been described in Late Paleozoic

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