Paleocene methane seep and wood-fall marine environments from Spitsbergen, Svalbard

Abstract

A recently discovered Paleocene seep locality from Fossildalen on Spitsbergen, Svalbard, is described. This is one of a very few seep communities of the latest Cretaceous-earliest Palaeogene age, and the best preserved Paleocene seep community known so far. The seep

The phylogeography and ecology of Oligobrachia frenulate species suggest a generalist chemosynthesis-based fauna in the arctic

“…Other than the few shallow water ones [ 42 , 72 , 73 ], and thereby for the majority of Arctic seep sites studied, the lack of specialist fauna represents a deviation from trends at seeps in other parts of the world. Even on geological timescales, a paucity of seep specialist fauna has been observed at Arctic seeps [ 71 , [74] , [75] , [76] , [77] ]. Based on our sediment geochemistry data, we posit that the presence of environments such as fjords and sounds with sulfidic conditions which are particularly widespread at the Nordic Seas and Barents Sea margin could have led to more generalized chemosymbiotic species than specialist ones.…”

New and Mesozoic-relict mollusks from Paleocene wood-fall communities in Urahoro Town, eastern Hokkaido, northern Japan

“…Based on the protobranch species from the Katsuhira Formation (Amano and Jenkins, 2017), the paleobathymetry of the formation can be estimated to be between 200 and 500 m in depth. According to Hryniewicz et al (2016), the Basilika Formation was deposited in an offshore prodelta. On the other hand, most Recent species of Provanna Dall, 1918 live deeper than 500 m (see Amano and Little, 2014, table 1).…”

“…Therefore, it is essential to reconstruct the evolution of these communities over geological time, especially for so-called ‘Cenozoic type’ chemosynthetic communities, including the vesicomyids and bathymodiolines, which first appeared in the middle Eocene (Amano and Kiel, 2007; Kiel and Amano, 2013). Although many Cretaceous chemosynthetic communities have been recorded (e.g., Campbell, 2006), only two Paleocene chemosynthetic communities have been reported, from the Panoche Hills in California (Schwartz et al, 2003) and Spitsbergen Island (Hryniewicz et al, 2016). Neither of these communities contained vesicomyids or bathymodiolines.…”

Crustaceans in Cold Seep Ecosystems: Fossil Record, Geographic Distribution, Taxonomic Composition, and Biology

“…Body fossils A group that is common in seeps today, but is only reported from three fossil seep localities consisting of four occurrences so far are squat lobsters (Galatheoidea and Chirostyloidea) (Figure 4). Shinkaia katapsyxis is described from the Eocene of Washington state (Schweitzer and Feldmann 2008;Kiel 2010a), "Galathea" spitzbergica and another galatheoid species were found in the late Paleocene of Spitsbergen (Hägg 1925;Gripp 1927;Vonderbank 1970;Hryniewicz et al 2016; pers. obs.…”