Morphological and molecular diversity of monothalamids (Rhizaria, Foraminifera), including two new species and a new genus, from SW Greenland

Single-chambered (monothalamous) foraminifera are poorly known compared to their multichambered relatives. In this first study of monothalamids from Greenland, we describe one new genus and two new species belonging to different clades from the Nuuk fjord system. Nujappikia idaliae Gooday & Holzmann gen. nov. sp. nov. (Clade Y) has a bottle-shaped test terminating in a single aperture located on a short neck. The flexible wall is basically organic but with a very fine agglutinated veneer. Bathyallogromia kalaallita Gooday & Holzmann sp. nov. (Clade C) has a broadly ovate test with an organic wall and a mound-like apertural structure. It is larger and genetically distinct from the two other Bathyallogromia species, both from the Southern Ocean. A survey of the morphological diversity of monothalamids in our samples revealed 49 morphospecies, of which 19, including the two new species, yielded DNA sequences. Five were assigned to the genera Bathysiphon, (Clade BM), Micrometula. (Clade BM), Psammophaga. (Clade E), Hippocrepinella (Clade D) and Crithionina (Clade J). The remaining twelve represented unknown taxa branching in clades A, C, F, and Y and one new clade. Our results add to grow-ing evidence that monothalamids are common and diverse in fjords and other high-latitude settings.(c) 2022 Elsevier GmbH. All rights reserved.