Ethological analysis of the trace fossil Zoophycos : hints from the Arctic Ocean

Abstract

Löwemark, L. 2011: Ethological analysis of the trace fossil Zoophycos: Hints from the Arctic Ocean. Lethaia, Vol. 45, pp. 290–298. The distribution of the trace fossil Zoophycos in Quaternary marine sediments from the Arctic Ocean was studied in twelve piston and gravity cores retrieved during the Swedish icebreaker expeditions YMER80, Arctic Ocean‐96 and LOMROG I & II. The sampled cores span an area from the Makarov Basin to the Fram Strait. Zoophycos was only found in two cores taken at more than 2 km water depth on the slope of the Lomonosov Ridge, but was absent in cores obtained at shallower depth, confirming earlier observations of the trace maker’s bathymetric preferences. The two cores containing Zoophycos are characterized by quiet sedimentation and slightly enhanced food flux compared with the general Arctic. The occurrence of Zoophycos in these cores in a setting that is characterized by extreme seasonal variations in food flux due to the total ice coverage during winters and high primary productivity during the long summer days, is interpreted to be a cache‐behaviour response to pulsed flux of food to the benthic realm. □Arctic Ocean, ethology, Quaternary, spreiten, trace fossils, Zoophycos.

Testing ethological hypotheses of the trace fossil Zoophycos based on Quaternary material from the Greenland and Norwegian Seas

“…These outflowing Arctic bottom waters are among the coldest on Earth, and form through a set of complex mechanisms in the Arctic Ocean (Rudels et al, 2005;Rudels and Friedrich, 2000). Consequently, if conditions are bad for Zoophycos-producing animals in the central Arctic, as indicated by radiograph studies showing only rare occurrences (Löwemark, 2012), then the number of larvae reaching and colonizing the Fram Strait area can be expected to be very low, resulting in few or no Zoophycos burrows. This kind of control on the distribution of benthic populations has been proposed both for intertidal (Roughgarden et al, 1988) and deep-marine communities (Bouchet and Taviani, 1992).…”

“…Previous studies have indicated a strong preference for calm conditions, relatively low sedimentation rates, intermediate organic carbon content, and possibly a preference for settings with a strong seasonal shift in the food flux (Löwemark, 2012;Löwemark et al, 2006;Löwemark and Schäfer, 2003;Wetzel and Werner, 1981). Especially the Greenland and Norwegian Seas are characterized by extremes both in the composition of the sediment, which often contains high amounts of ice rafted debris, and in the extreme differences in primary productivity between winter and summer.…”

Evolutionary trend of Zoophycos morphotypes from the Upper Cretaceous–Lower Miocene in the type pelagic sections of Gubbio, Italy

“…Modern deep‐sea Zoophycos have been also extensively studied using X‐ray radiographs (Wetzel & Werner ; Löwemark & Schäfer ; Löwemark et al . ; see Löwemark , for recent reviews), and recently by a high‐resolution digital image treatment (Dorador & Rodríguez‐Tovar ; Dorador et al . ,b; Rodríguez‐Tovar & Dorador , ).…”

“…is generally assumed to be a trace of unknown deposit feeders (or partly chemichnia), among which sipunculids, polychaete annelids, arthropods or enteropneust hemichordates are the most commonly invoked tracemakers (Wetzel & Werner ; Kotake , ; Ekdale & Lewis ; Olivero & Gaillard , ; Löwemark & Grootes ; Löwemark et al . ; Löwemark ). Zoophycos is one of the most problematic burrow systems to study and interpret in the fossil record (Seilacher ).…”

Lower Devonian tempestites in western Yangtze, South China: insight fromZoophycosichnofabrics

“…They include deposit feeding (Wetzel and Werner, 1981;Ekdale and Lewis, 1991;Olivero and Gaillard, 1996), detritus feeding (Kotake, 1989(Kotake, , 1991(Kotake, , 1992, the refuse dump model (Bromley, 1991;Löwemark and Shäfer, 2003), the cache model (Fu and Werner, 1995;Bromley et al, 1999;Miller and D'Alberto, 2001;Bromley and Hanken, 2003;Löwemark and Shäfer, 2003;Löwemark, 2012) and the gardening model (Bromley, 1991;Löwemark et al, 2004;Gong et al, 2007Gong et al, , 2008. They include deposit feeding (Wetzel and Werner, 1981;Ekdale and Lewis, 1991;Olivero and Gaillard, 1996), detritus feeding (Kotake, 1989(Kotake, , 1991(Kotake, , 1992, the refuse dump model (Bromley, 1991;Löwemark and Shäfer, 2003), the cache model (Fu and Werner, 1995;Bromley et al, 1999;Miller and D'Alberto, 2001;Bromley and Hanken, 2003;Löwemark and Shäfer, 2003;Löwemark, 2012) and the gardening model (Bromley, 1991;Löwemark et al, 2004;Gong et al, 2007Gong et al, , 2008.…”