On the genus Vanikoropsis Meek, 1876 (Gastropoda, Caenogastropoda) from the Paleocene of Denmark and West Greenland with descriptions of three new species

The predominantly Cretaceous gastropod genus Vanikoropsis Meek, 1876 is represented in the Paleocene of Denmark and West Greenland by four species, of which three are established herein as new, viz. Vanikoropsis mortenseni n. sp., Vanikoropsis (s.l.) jakobseni n. sp. and Vanikoropsis (s.l.) bashforthi n. sp. The Danish species was found in a boulder of Kerteminde Marl (Selandian, middle Paleocene) from Gundstrup, while the species from West Greenland were found in the localities Sonja Lens and Qaarsutjægerdal on the Nuussuaq peninsula (late Danian, early Paleocene). The Danish species extends the stratigraphic range of the genus into the middle Paleocene and supports the affinities of the Kerteminde Marl fauna to the Paleocene fauna of West Greenland.

The K–T boundary strata north of Korsnæb, Stevns Klint, Denmark – evolution and geometry revealed in a long, horizontal profile

A 460 m long profile of the Cretaceous–Paleogene (K–T) boundary strata at Stevns Klint was measured by the late Professor A. Rosenkrantz probably in 1944. The measured profile was inherited by Finn Surlyk around 1974 together with other original boundary data. This material was dug up in a long-forgotten drawer in connection with detailed field work by the co-authors on the boundary succession in the late spring and summer of 2021. The profile illustrates the stratigraphy, geometry and palaeotopography of the boundary strata in unprecedented detail. The part of the cliff illustrated in the profile is today partly covered by beach ridges composed of flint rubble but is situated below the finest section of the lower Danian bryozoan mounds exposed at Stevns Klint. This coastal section is situated immediately adjacent to a large limestone quarry and was planned to be quarried away around 1937, but was saved by A. Rosenkrantz who demonstrated its great scientific and educational value to the authorities.

Furongian (upper Cambrian) trilobites and agnostoids from the Alum Shale Formation of Bornholm, Denmark: revised taxonomy and biostratigraphy

The Furongian (upper Cambrian) trilobite-agnostoid fauna from the Alum Shale Formation of Bornholm, Denmark, is reviewed and revised. The study is based on the museum material stored at the Natural History Museum of Denmark, including the material originally monographed by C. Poulsen (1923) [Bornholms Olenuslag og deres fauna. Danmarks Geologiske Undersøgelse II. Række, Vol. 40, 83 pp]. A total of 8502 specimens, mostly disarticulated sclerites, have been registered. The taxonomy of all species is updated and the best preserved specimens are illustrated. A total of 39 olenid and 5 agnostoid taxa (incl. the Miaolingian Agnostus pisiformis) are recorded including one new species, Ctenopyge magna n. sp. Two specimens of Ctenopyge, treated in open nomenclature as Ctenopyge sp. 1 and sp. 2, may also rep-resent new species. 14 taxa have not been previously reported from Bornholm, viz. Ctenopyge ahlbergi, Ctenopyge tumidoides, Eurycare brevicauda, Leptoplastus abnormis, Leptoplastus crassicornis, Olenus transversus, Parabolina lobata praecurrens, Peltura acu-tidens, Peltura minor, Peltura westergaardi, Protopeltura planicauda, Protopeltura praecursor, Pseudagnostus leptoplastorum? and Sphaerophthalmus drytonensis. Ctenopyge pecten and Ctenopyge affinis are also new to Bornholm as the material formerly described under these names represent Ctenopyge tenuis and C. magna n. sp., respectively. Lotagnostus americanus, Ctenopyge fletcheri, Sphaerophthalmus alatus and Triangulopyge humilis were described under different names by C. Poulsen (1923). Peltura westergaardi and Ctenopyge tenuis are elevated from subspecies to species rank. A redescription of Leptoplastus bornholmensis is presented; the species is transferred to Eurycare. The identification of isolated skeletal parts of L. abnormis and Leptoplastus ovatus and Sphaerophthalmus flagellifer and S. drytonensis are remarked on. The presence of three agnostoid and 14 trilobite zones is confirmed by fossils and all six Furongian superzones are developed on Bornholm. At least the Leptoplastus paucisegmentatus and Leptoplastus raphidophorus zones seem to be absent. Other undocumented zones may be unfossiliferous, not exposed or truly absent. Three different trilobite assemblages (potential subzones) are discerned in the Peltura acu-tidens–Ctenopyge tumida Zone; Ctenopyge tumidoides and Sphaerophthalmus angustus range into the basal part of this zone. All exposures of the Furongian Alum Shale Formation along the Læså and Øleå streams on southern Bornholm are briefly described including GPS coordinates.

Stratigraphy and petrophysical characteristics of Lower Paleocene cool-water carbonates, Faxe quarry, Denmark

The Faxe limestone quarry in eastern Denmark exposes Danian (Lower Paleocene) cool-water carbonate deposits. They constitute remnants of an apparent build-up that covers about 12 km2 today. The Danian deposits at Faxe are conspicuous due to their pronounced thickness of coral limestone relative to the regional carbonate system. In the Faxe quarry, scleractinian corals are uniquely exposed in up to 30 m high mounds. The rapid accumulation of scleractinians combined with induration of the mounds may locally have protected the limestone from Quaternary glacial erosion and created a Danian thickness anomaly at Faxe. The position of Faxe above a local fault-bounded basement high and the extent of coral limestone has been better defined by new mapping. A mapped lithostratigraphic surface in the quarry reveals the large-scale organisation of nested bryozoan mounds on three elongated ridges striking NW–SE. The main scleractinian coral mounds are located above this horizon. Data for reservoir characterisation, mainly of the bryozoan mounds, were collected as photographs of the outcrop, petrophysical and petrographical data from cored boreholes, and as ground-penetrating radar sections. Old boreholes and measured sections were used to reconstruct the build-up, and new nannofossil data allow a discussion of stratigraphy and accumulation rate. The petrophysical data show that common mound-building bryozoan packstone has higher permeability and lower capillary entry pressure than chalk, whereas less commonly occurring grain-dominated packstone and grainstone deposits from local higher-energy sites of the mound complex were found to have reduced amounts of coccolith mud, significantly higher permeability and a higher degree of lithification. Based on biostratigraphic age constraints, correlation of flint – limestone couplets and recog-nised hierarchical patterns, we develop a cyclostratigraphy for the middle Danian and suggest that cyclicity in lithology and petrophysical characteristics of bryozoan limestone are controlled by precession and eccentricity of the orbit of the Earth.

Claus Heinberg (1945–2021) – Trace fossils, Greenland expeditions and bivalves of the K–T boundary strata

The eminent palaeontologist and Greenland explorer Claus Heinberg was born in 1945 and died in 1921 after prolonged illness. His scientific production was focused on two remarkably different subjects: the bivalve fauna of the Cretaceous–Palaeogene (K–T) boundary beds and the Mesozoic geology and stratigraphy of eastern North Greenland. He was employed at Roskilde University during most of his career until he retired in 2012. He was part of a cross disciplinary collaborative environment, comprising biologists, geographers, geologists, sociologists, civil engineers and chi-tects. He was a highly engaged social debater of a wide spectrum of societal subjects throughout his life. He was a fine person, a good colleague and friend.

A possible phytosaurian (Archosauria, Pseudosuchia) coprolite from the Late Trias-sic Fleming Fjord Group of Jameson Land, central East Greenland

A large, well-preserved vertebrate coprolite was found in a lacustrine sediment in the Malmros Klint Formation of the Late Triassic Fleming Fjord Group in the Jameson Land Basin, central East Greenland. The size and internal and external morphology of the coprolite is consistent with that of crocodilian coprolites and one end of the coprolite exhibits evidence of post-egestion trampling. As the associated vertebrate fauna of the Fleming Fjord Group contains abundant remains of pseudosuchian phytosaurs, the coprolite is interpreted as being from a large phytosaur.

Prognathodon (Squamata, Mosasauridae) from the Maastrichtian chalk of Denmark

Two mosasaur tooth crowns collected from the Maastrichtian chalk sequences of Stevns Klint and Møns Klint are here assigned to Prognathodon, a mosasaur genus hitherto unknown from Denmark. Together with previous records of the mosasaurs Plioplatecarpus, Mosasaurus and Carinodens, these new finds of Prognathodon document the coexistence of four mosasaurid genera in the Danish chalk and underscore simi-larities to coeval assemblages from the Maastrichtian type area in the Netherlands and Belgium.

Carbon isotope trends in north-west European mosasaurs (Squamata; Late Cretaceous)

The carbon stable isotope composition (δ13C) of tooth enamel in mosasaurid squa-mates reflects aspects of their diet and diving behaviour. Here we present new δ13C data for such marine squamates from the Maastrichtian of Denmark and compare these with results obtained in previous studies from the lower-latitude type area of the Maastrichtian Stage (latest Cretaceous; 72.1–66.0 Ma) in the south-east Nether-lands and north-east Belgium. For the Danish samples, there is a weak correlation between mosasaur body size and δ13C values, with larger-sized taxa having lower δ13C values, comparable to what has previously been observed for mosasaurs from the Maastrichtian type area.

A tale from the middle Paleocene of Denmark: A tube-dwelling predator documented by the ichnofossil Lepidenteron mortenseni n. isp. and its predominant prey, Bobbitichthys n. gen. rosenkrantzi (Macroridae, Teleostei)

The ichnofossil Lepidenteron provides a unique taphonomic window into the life habits of a tube-dwelling predator, probably an eunicid polychaete, and its fish prey. Here we describe a new tube-like ichnofossil Lepidenteron mortenseni n. isp. from the Kerteminde Marl (100–150 m palaeo-water depth) from the Gundstrup gravel pit near Odense, Fyn, Denmark. 110 individual tubes were examined which contain fish remains, including a variety of disarticulated bones and otoliths, by far dominated by a single gadiform taxon referred herein to as Bobbitichthys n. gen. The isolated otoliths here associated with disarticulated gadiform bones have previously been described, from the time equivalent Lellinge Greensand exposed in the Copen-hagen area, as Hymenocephalus rosenkrantzi, a grenadier fish (family Macrouridae). The abundance of associated bones and otoliths in the examined tubes allowed us to reconstruct part of the cranial configuration of Bobbitichthys rosenkrantzi and to tentatively interpret it as a stem macrourid. Bobbitichthys rosenkrantzi represents the earliest grenadier known in the fossil record. Additional, although considerably less abundant, skeletal remains and otoliths have been tentatively referred to a long-fin bonefish (family Pterothrissidae, Pterothrissus? conchaeformis), a viviparous brotula (family Bythitidae, Bidenichthys? lapierrei), a conger eel (family Congridae, possibly belonging to Rhynchoconger angulosus), and another unidentified gadiform.

Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Miaolingian Series), western North Greenland (Laurentia)

Trilobites dominantly of middle Cambrian (Miaolingian Series, Wuliuan Stage) age are described from the Telt Bugt Formation of Daugaard-Jensen Land, western North Greenland (Laurentia), which is a correlative of the Cape Wood Formation of Inglefield Land and Ellesmere Island, Nunavut. Four biozones are recognised in Daugaard-Jensen Land, representing the Delamaran and Topazan regional stages of the western USA. The basal Plagiura–Poliella Biozone, with Mexicella cf. robusta, Kochiella, Fieldaspis? and Plagiura?, straddles the Cambrian Series 2–Miaolingian Series boundary. It is overlain by the Mexicella mexicana Biozone, recognised for the first time in Greenland, with rare specimens of Caborcella arrojosensis. The Glossopleura walcotti Biozone, with Glossopleura, Clavaspidella and Polypleuraspis, dominates the succession in eastern Daugaard-Jensen Land but is seemingly not represented in the type section in western outcrops, likely reflecting the drastic thinning of the formation towards the north-west. The Ehmaniella Biozone, with Ehmaniella, Clappaspsis, Blainia and Blainiopsis, is the youngest recognised biozone. The presence of Drumian Stage strata reported elsewhere in North Greenland and adjacent Ellesmere Island has not been confirmed in Daugaard-Jensen Land. Lower beds of the Cass Fjord Formation, which directly overlie the Telt Bugt Formation, are assigned to the Guzhangian Stage. New species: Fieldaspis? iubilaei, Ehmaniella tupeqarfik.