Scleractinian Corals from the Upper Cretaceous and Lower Tertiary of Nûgssuaq, West Greenland.

Abstract

Localities and deposits in north-west Nûgssuaq yielding fossil corals of the order Scleractinia are described. The age of the corals is Campanian ?, Maastrichtian and Lower Paleocene (Danian), on the basis of other marine fossils. 22 species are considered; 7 are described as new and are indigenous, 2 are possibly North American forms, 3 are known from Europe, and 10 are identifiable only to generic level. The following genera and subgenera are represented: Haimesiastraea (Haimesiastraea), H. (Peruviastrea) ? , Discotrochus ? , Astrangia ( Coenangia) ?, Oculina, Caryophyllia, Trochocyathus, Paracyathus, Stephanocyathus (Stephanocyathus), Desmophyllum ?, Lophelia ?, Parasmilia, Flabellum, Balanophyllia, and Dendrophyllia. In addition, two new genera are described: Kangiliacyathus and Faksephyllia. Certain Danian corals from Scandinavia are also revised. In a survey of habitats, the lithology of the coral localities is considered together with bathymetric and thermal ranges known for scleractinian genera and species from other parts of the world. Depth and temperature of the Campanian and Maastrichtian seas in Greenland cannot be estimated with any accuracy. The Lower and Upper Danian seas were generally rather shallow. There is little evidence on which to judge the Danian climate. Two species were perhaps hermatypic (no reef structures have been found). The remaining scleractinians are presumed to have been ahermatypic. A non-reef coral association has been found. Lower Danian rather sparsely populated polytypic coral thickets show signs of continual disturbance from water turbulence. The approximate depth of formation of these thickets appears to have been 80 m or shallower, which appears to be less than is usual for coral structures of this type. Some Lower Paleocene species provide conclusive evidence of a direct connection between the Danian seas of West Greenland and of Scandinavia.