DOI: 10.5061/dryad.nh74kg8
title: A Paleocene (Danian) marine osteoglossid (Teleostei, Osteoglossomorpha) from the Nuussuaq Basin of Greenland, with a brief review of Palaeogene marine bonytongue fishes

description: The early Palaeogene represents a key interval in the evolution of modern
 marine fish faunas. Together with the first appearances of many familiar
 fish lineages characteristic of contemporary marine environments, early
 Palaeogene marine deposits worldwide feature the occurrence of
 osteoglossid bonytongues. Their presence in marine rocks is surprising, as
 these fishes are strictly associated with freshwater environments in
 modern settings and other parts of the fossil record. Despite its possible
 relevance to faunal recovery after the K–Pg extinction, this marine
 osteoglossid radiation is relatively understudied. Here we describe an
 osteoglossid specimen from marine Danian deposits of western Greenland
 (Eqalulik Formation, northern Nuussuaq Peninsula). It consists of
 disarticulated cranial, pectoral and vertebral material belonging to a
 relatively large-bodied predator, similar to the widespread †Brychaetus
 but with some distinctive features. This specimen expands the geographic
 range of extinct osteoglossids to the Arctic and represents one of the
 earliest records of this group in marine deposits. We review other fossil
 occurrences of marine osteoglossids, highlighting temporal and
 biogeographic patterns that characterize their rise, diversification and
 sudden disappearance in the middle Eocene. It is likely that the
 transition from freshwater to marine environments occurred around the K–Pg
 boundary, possibly related to ecological replacement of predatory fish
 lineages that went extinct at the end of the Cretaceous. Further study of
 the Eqalulik Formation fauna could yield additional insight into the
 consequences of the end-Cretaceous extinction on marine fish evolution and
 on the assembly of modern marine faunas.
description: 3D bone models from NHMD
 72014 A.ply files of individual
 bones preserved in specimen no. NHMD 72014 A and segmented using Mimics v.
 19.0GreenlandOsteoglossidLeft_plyFiles.zip3D bone models from NHMD 72014 B.ply files of individual bones preserved in specimen no. NHMD 72014 B and segmented using Mimics v. 19.0GreenlandOsteoglossidRight_plyFiles.zipμCT data for NHMD 72014 A.7z file containing micro-computed tomography data for specimen NHMD 72014 A as a .mcs file (can be opened by the program Mimics). Voltage: 210 kV; current: 220 μA; filter: 2.5 mm copper; reflection target: tungsten; effective pixel size: 92 μm; scanning facility: University of Michigan CTEES.GreenlandOsteoglossidLeft_NHMD72014A.7zμCT data for NHMD 72014 B.7z file containing micro-computed tomography data for specimen NHMD 72014 B as a .mcs file (can be opened by the program Mimics). Voltage: 210 kV; current: 220 μA; filter: 2.5 mm copper; reflection target: tungsten; effective pixel size: 92 μm; scanning facility: University of Michigan CTEES.GreenlandOsteoglossidRight_NHMD72014B.7zμCT data as DICOM stack for NHMD 72014A.7z file containing micro-computed tomography data for specimen NHMD 72014 A as a DICOM image stack. Voltage: 210 kV; current: 220 μA; filter: 2.5 mm copper; reflection target: tungsten; effective pixel size: 92 μm; scanning facility: University of Michigan CTEES.GreenlandOsteoglossidLeft_NHMD72014A_dcm.7zμCT data as DICOM stack for NHMD 72014B.7z file containing micro-computed tomography data for specimen NHMD 72014 B as DICOM image stack. Voltage: 210 kV; current: 220 μA; filter: 2.5 mm copper; reflection target: tungsten; effective pixel size: 92 μm; scanning facility: University of Michigan CTEES.GreenlandOsteoglossidRight_NHMD72014B_dcm.7z