A late Paleocene fauna from shallow-water chemosynthesis-based ecosystems, Spitsbergen, Svalbard

Abstract

We present a systematic study of late Paleocene macrofauna from methane seep carbonates and associated driftwood in the shallow marine Basilika Formation, Spitsbergen, Svalbard. The fauna is composed of 22 taxa, comprising one brachiopod, 14 bivalves, three gastropods, three crustaceans, and one bony fish. The reported fish remains are among the first vertebrate body fossils from the Paleogene of Spitsbergen. One genus is new: the munidid decapod Valamunida Klompmaker and Robins gen. nov. Four new species are described: the terebratulide brachiopod Neoliothyrina nakremi Bitner sp. nov., the protobranch bivalve Yoldiella spitsbergensis Amano sp. nov., the xylophagain bivalve Xylophagella littlei Hryniewicz sp. nov., and the munidid decapod Valamunida haeggi Klompmaker and Robins gen. et sp. nov. New combinations are provided for the mytilid bivalve Inoperna plenicostata, the thyasirid bivalve Rhacothyas spitzbergensis, the ampullinid gastropod Globularia isfjordensis, and the munidid decapod Protomunida spitzbergica. Thirteen taxa are left in open nomenclature. The fauna contains a few last occurrences of Cretaceous survivors into the Paleocene, as well as first occurrences of Cenozoic taxa. It is composed of chemosymbiotic thyasirid bivalves and background species common in the northern Atlantic and Arctic during the Paleocene. Our results provide no evidence for a Paleocene origin of vesicomyid and bathymodiolin bivalves typical for Eocene and younger seep environments; instead, the Paleo cene seeps of the Basilika Formation are more similar to their Late Cretaceous equi valents rich in thyasirids.

Palaeoecological analysis of a methane seep deposit from the Upper Cretaceous (Maastrichtian) of the U.S. Western Interior

“…Palaeocene (Thanetian) shallow‐water seeps from Spitsbergen are also dominated by chemosymbiotic thyasirid bivalves of the genus Conchocele along with a high abundance of background fauna (Hryniewicz et al . 2019). Other Cretaceous and Palaeogene shallow seep faunas also typically contain seep‐obligate gastropod taxa, which are absent from the WIS (Kaim et al .…”

Cold Seeps in a Warming Arctic: Insights for Benthic Ecology

“…A distinct feature of Arctic seeps is the absence of the hallmark chemosymbiotic species (e.g., vesicomyid clams, vestimentiferan worms, and bathymodioline mussels). No evidence has yet been found for the latter two groups at Arctic seeps in recent geological time (Hryniewicz et al, 2019). Vesicomyid shells have, however, been recovered from several Arctic seep locations (Hansen et al, 2017 and references herein) ( Table 1).…”

Predation in the marine fossil record: Studies, data, recognition, environmental factors, and behavior

“…Eocene-to-Miocene seep deposits in western Washington state, USA, also showed a decline in predator abundance and increase in proportion of obligate seep taxa with depth (Kiel, 2010). Direct evidence of predation at cold seeps is rare, but drill holes have been reported at low frequencies for some sites of Eocene age and younger (see Amano and Kiel, 2007;Hryniewicz et al, 2019, and references for more examples). Durophagous predation in cold seep environments is also known.…”