Ammopemphix hemisphaericus sp. nov., a new attached agglutinated foraminifer from the Pleistocene of the Arctic Ocean, a
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ORIGINAL ARTICLE
Ammopemphix hemisphaericus sp. nov., a new attached agglutinated foraminifer from the Pleistocene of the Arctic Ocean, and the taxonomic status of the genus Ammopemphix Loeblich, 1952 Anna Waśkowska1 · Michael A. Kaminski2 Received: 21 March 2018 / Accepted: 15 May 2018 / Published online: 4 June 2018 © The Author(s) 2018
Abstract The new species Ammopemphix hemisphaericus sp. nov. is described from Pleistocene sediments of the Central Arctic Ocean. The species is a finely agglutinated monothalamous form with hemispherical shape and a terminal aperture located at the top of the test, often occurring in pseudocolonies. A. hemisphaericus sp. nov. attaches itself to inorganic or organic substrates, often growing attached to the inside surfaces of calcareous or agglutinated foraminiferal tests. Pseudocolonies of A. hemisphaericus sp. nov. may also attach themselves to previous generations of Ammopemphix individuals. Based on our study of numerous specimens of Ammopemphix from the Central Arctic Ocean, we propose modifications to the description of the genus. The genus may be pseudocolonial or consist of isolated individuals, and in the case of pseudocolonial forms, individual specimens may be arranged randomly or symmetrically. The genus Ammopemphix is found mostly in polar regions, and is here reported for the first time from the fossil record. Keywords Agglutinated foraminifera · Arctic Ocean · Pleistocene
Introduction The glacial environment of the deep Arctic Ocean yields species that are predisposed to life in cold and oligotrophic conditions. Because of profound changes in sea-ice cover, surface productivity, and sedimentation linked to glacial/interglacial cycles, the benthic foraminiferal and ostracode assemblages found in the glacial Arctic Ocean are much less abundant and diverse than in the interglacial faunas [2]. Glacial assemblages reported from sediment cores are sparse and typically only consist of a few species of agglutinated forms [6, 7, 13]. During the summer of 2014, four long kastenlot cores and 36 gravity cores were collected on the Lomonosov Ridge during Expedition 87 of the R/V Polarstern. The Pleistocene foraminiferal assemblages from these cores consist of * Anna Waśkowska [email protected] 1
Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, al. Mickiewicza 30, 30‑059 Kraków, Poland
Geosciences Department, College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum and Minerals, PO Box 701, Dhahran 31261, Saudi Arabia
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approximately 20 species of agglutinated foraminifera [13]. The taxonomy and biostratigraphy of the benthic foraminiferal assemblages from the PS87 cores will be described separately. The purpose of this paper is to describe an enigmatic new species that lives attached to sediment particles, or most often to fragments of other specimens of agglutinated foraminifera. The genus Ammopemphix has been previously reported from the Arctic and Antarctic seas [e.g., 3, 14, 15
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