The early Pleistocene whale-fall community of Bargiano (Umbria, Central Italy): Paleoecological insights from benthic foraminifera and brachyuran crabs

[摘要] New insights into communities of benthic foraminifera and decapods, associated with whale-fall events (WFE) in a relatively shallow sea environment, are reported here for the first time from the early Pleistocene of Bargiano (southwestern Umbria, Italy). The inferred paleodepth of these WFEs is not greater than 100−150 m and, on the basis of more general stratigraphic data, took place over an estimated period of about 50,000 years. The foraminifera assemblages associated with these WFEs are low in number of planktonic and benthic taxa, and six benthic species dominate: the shallow infaunal species Bigenerina nodosaria, Bannerella gibbosa, Marginulinopsis costata, andVaginulina cf. V. striatissima, along with the epifaunal speciesLenticulina calcar and Siphotextularia concava. Because these opportunistic species respond to short-term favorable conditions by increasing in number and maintaining stable populations, the presence of high numbers of individuals of these species in association with three recognized WFEs provides evidence that a nutrient-rich environment favored their proliferation. The occurrence of previously unreported benthic foraminifera taxa (across the three WFEs), along with the presence of the crab species Albaidaplax ispalensis (Goneplacidae) and Chlinocephalus demissifrons (Euryplacidae) (in at least one WFE), offer new insights into shallow sea whale-fall fossil communities.

[学科分类] 地质学

[关键词] brachyuran crabsAngela Baldanza;Roberto Bizzarri;Federico Famiani;Alessandro Garassino;Giovanni Pasini;Marco Cherin;Francesco Rosatini;Decapoda;Whale-fall events;paleoecology;Calabrian;Paleo-Mediterranean Sea