Abstract
The intricate geological evolution of the Arctic Ocean is paralleled by complexities in the biogeographical and phylogenetical histories of the Arctic biota, including bryozoans. Here we present revised taxonomic descriptions for all known species of the bryozoan genus Pseudoflustra, and use the present-day distributions and phylogenetic relationships between these species to infer the historical biogeography of the genus. Nine species belonging to the genus Pseudoflustra are recognized in the Arctic and North Atlantic. One new species, previously identified as Ichthyaria aviculata, is described as Pseudoflustra radeki sp. nov. Another species, previously assigned to Smittoidea as S. perrieri, is transferred to Pseudoflustra. Biogeographical analysis of Pseudoflustra reveals that species distributions mostly match current patterns pertaining in the North Atlantic and Arctic Ocean. Distributions were probably shaped by recent geological history as present-day current directions in the Arctic Ocean are believed to have been similar for at least the last 120 000 years. Phylogenetic analysis of Pseudoflustra places the five Arctic-North Atlantic species in a clade crownward of a paraphyletic grouping of North Atlantic species. Given that the Arctic Ocean was fully glaciated until 18 000 years, the most likely explanation for this phylogeographical pattern is that species of Pseudoflustra colonized the Arctic relatively recently from North Atlantic sources. However, a fuller understanding of the origin of Pseudoflustra in the Arctic will require molecular and fossil data, neither of which are currently available.
Highlights
Animal and plant species making up the marine biota currently inhabiting the Arctic Ocean have undergone varied evolutionary histories
Molecular studies of the red alga Phycodrys rubens, which is currently distributed throughout the Arctic and North Atlantic, show that it originated in the Pacific and colonized the North Atlantic after the opening of the Bering Strait about 3–3.5 Ma [2]
Colonization was accomplished by the few survivors that had been able to retreat into the North Atlantic or North Pacific, or had taken refuge in unglaciated shelf areas of the East Siberian Sea, the Beaufort Sea or deeper bathyal parts of the Arctic Ocean [1,3]
Summary
Animal and plant species making up the marine biota currently inhabiting the Arctic Ocean have undergone varied evolutionary histories. During the last major glaciation of the Arctic, which reached its zenith around 18 000 years ago and ended some 6000 years ago, vast areas of the Arctic continental shelf were covered by ice sheets [1,3,8] These ice sheets extended over North America, Greenland, Iceland, Scandinavia, the Barents Sea and the Kara Sea; only parts of the continental shelves of the Chukchi, Beaufort and East Siberian seas remained largely unglaciated, despite being almost entirely emergent [1,8]. During this period the Arctic shelf fauna was almost eradicated. Colonization was accomplished by the few survivors that had been able to retreat into the North Atlantic or North Pacific, or had taken refuge in unglaciated shelf areas of the East Siberian Sea, the Beaufort Sea or deeper bathyal parts of the Arctic Ocean [1,3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
