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Holm, T.B., Delsett, L.L. & Alsen, P. 2022. Vertebral size ratios and the ichthyosaurian vertebral column – a case study based on Late Jurassic fossils from North-East Greenland.
Goñi, I & Cuny, G. 2022. New record of the genus Ptychodus Agassiz, 1834, (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of Bornholm (Denmark).
Waight, T., Stokholm, M., Heredia, B. & Thomsen, T.B. 2022. U-Pb zircon and titanite age of the Christiansø granite, Ertholmene, Denmark, and correlation with other Bornholm granitoids.
Bennike, O., Claudi-Hansen, L., Magnussen, B. & Wiberg-Larsen, P. 2022. Macrofossil studies of Lateglacial sediments from Regstrup, north-west Sjælland, Denmark.
Carnevale, G., Schwarzhans, W., Schrøder, A.N. & Lindow, B.E.K. 2022. An Eocene conger eel (Teleostei, Anguilliformes) from the Lillebælt Clay Formation, Denmark.
Peel, J.S. & Kouchinsky, A. 2022. Middle Cambrian (Miaolingian Series, Wuliuan Stage) molluscs and mollusc-like microfossils from North Greenland (Laurentia).
Bennike, O., Astrup, P.M., Odgaard, B.V., Pearce, C. & Wiberg-Larsen, P. 2022. Holocene development of Brabrand Fjord, eastern Jylland, Denmark.
Jésus, V.J.P., Mateus, O., Milàn, J. & Clemmensen, L.B. 2022. First occurrence of a frog-like batrachian (Amphibia) in the Late Triassic Fleming Fjord Group, central East Greenland.
Vallon, L.H. & Rindsberg, A.K. 2022. Cutting through sponge and time – a new record of Koptichnus rasmussenae (trace fossil) from the Kerteminde Marl (middle Paleocene), Denmark.
Duffin, C.J. & Milàn, J. 2022. Further holocephalian remains from the Hasle Formation (Early Jurassic) of Denmark.
Vertebral size ratios and the ichthyosaurian vertebral column – a case study based on Late Jurassic fossils from North-East Greenland
Holm, T.B., Delsett, L.L. & Alsen, P. 2022. Vertebral size ratios and the ichthyosaurian vertebral column – a case study based on Late Jurassic fossils from North-East Greenland.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 1–17.
ISSN 2245-7070. https://doi.org/10.37570/bgsd-2022-70-01
Abstract: Vertebral centra are some of the most common fossils from ichthyosaurs and thus valuable for understanding these marine reptiles. This study sets out to provide further information on the dimensional ratios of centra and how these might be used to obtain more information about an assemblage of Late Jurassic disarticulated centra found at Kingofjeldet on Kuhn Ø in North-East Greenland in 2017. The centra are used to test whether vertebral ratios (H:W and H:L) can be used to assign disarticulated and possibly weathered centra to a region in the vertebral column. In order to evaluate this, the ratios of the centra from Greenland were compared with those of five articulated and well-known ophthalmosaurid specimens, as well as classical traits based on morphology. Assigning the correct position in the vertebral column from ratios is, however, not straightforward. Firstly, comparing different ichthyosaur taxa gives different possible positions for the disarticulated centra. Secondly, centra from different vertebral regions commonly display similar ratios. Thirdly, ratios are sensitive to alteration by taphonomic processes. The ratios of the centra hints towards an ichthyosaur with a more regionalised vertebral column being present in the Late Jurassic sea of North-East Greenland. Further studies are needed to improve our understanding of the significance of the degree of regionalisation of the vertebral column among ichthyosaurs.
Keywords: Ichthyosaur, vertebrae, ratios, morphology, vertebral regionalisation, Ugpik Ravine Member, Kuhn Ø, Greenland.
Address: Thomas Bang Holm [tholm [at] snm [dot] ku [dot] dk], Natural History Museum of Denmark, University of Copenhagen, Gothersgade 130, DK-1123 Copenhagen K, Denmark. Lene Liebe Delsett [DelsettL [at] si [dot] edu], Department of Paleobiology, National Museum of Natural History,
Smithsonian Institution, 1000 Madison Drive NW Washington, DC-20560, USA. Peter Alsen [pal [at] geus [dot] dk], Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
New record of the genus Ptychodus Agassiz, 1834, (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of Bornholm (Denmark)
Goñi, I & Cuny, G. 2022. New record of the genus Ptychodus Agassiz, 1834, (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of Bornholm (Denmark).
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 19–25.
ISSN 2245-7070. https://doi.org/10.37570/bgsd-2022-70-02
Abstract: Nine shark teeth were collected at Arnager in the south-western part of the island of Bornholm (Baltic Sea, Denmark). They all come from the basal conglomerate of the Coniacian (Upper Cretaceous) Arnager Limestone Formation and belong to the genus Ptychodus Agassiz, 1834. Three different species are identified: P. altior, P. latissimus and P. mammillaris, which were hitherto unknown in Denmark.
Keywords: Ptychodus, shark tooth, Late Cretaceous, Coniacian, Bornholm, Denmark.
Address: Iban Goñi [iban [dot] goni [at] etu [dot] univ-lyon1 [dot] fr] and Gilles Cuny [gilles [dot] cuny [at] univ-lyon1 [dot] fr], both Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622 Villeurbanne, France.
Download PDF (1,36 Mb)U-Pb zircon and titanite age of the Christiansø granite, Ertholmene, Denmark, and correlation with other Bornholm granitoids.
Waight, T., Stokholm, M., Heredia, B. & Thomsen, T.B. 2022. U-Pb zircon and titanite age of the Christiansø granite, Ertholmene, Denmark, and correlation with other Bornholm granitoids.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 27–38.
ISSN 2245-7070. https://doi.org/10.37570/bgsd-2022-70-03
Abstract: A granitic sample from the Danish island of Christiansø in the Ertholmene island group north of Bornholm is described petrographically and geochemically, and dated using U-Pb in zircon and titanite. Zircon systematics in the sample are complicated by abundant Pb loss and a large population of zircons interpreted as being inherited. Removal of highly disturbed zircons, imprecise analyses, and assumed inherited zircons yield an upper intercept date of 1500 ± 18 Ma (MSWD = 13, n = 58). Removal of zircons with high common Pb from this population yields an identical result of 1500 ± 22 Ma (MSWD = 8, n = 34). Zircons that are ≤3% discordant give a weighted average 206Pb/238U age of 1458 ± 12 Ma (MSWD = 3.0, n = 18), and a weighted average 207Pb/206Pb age of 1495 ± 14 Ma (MSWD = 4.7, n = 19). Titanites from the sample yield a lower intercept age of 1448 ± 15 Ma (MSWD = 6.8, n = 45). The sample contains a significant number of inherited grains indicative of ages around 1.7–1.8 Ga. The relatively large MSWDs for these age determinations indicate geological complexity, likely reflecting Pb loss, and the possible presence of inherited zircons which suffered
major Pb loss during incorporation in the granitic magma. The zircon and titanite dates agree reasonably well with previous age determinations on felsic lithologies from the Bornholm mainland, as well as from the Blekinge Province of southern Sweden. Petrographically and geochemically, the Christiansø granite is indistinguishable from, and can be correlated with, the A-type granites and gneisses which occur on Bornholm. The high abundance of disturbed and inherited zircons (c. 1.7–1.8 Ga) may indicate that the granite was intruded into and assimilated a nearby region of unexposed Transscandinavian Igneous Belt rocks. The somewhat altered nature of the rock, and overall disturbance of U-Pb zircon systematics, suggest alteration associated with fluid-flow along nearby faults defining the northern margin of the Sorgenfrei–Tornquist Zone.
Keywords: Granite, Bornholm, Ertholmene, U-Pb zircon, titanite.
Address: Tod Waight [todw [at] ign [dot] ku [dot] dk], Department of Geosciences and Natural Resource Management (Geology Section), University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark. Mikael Stokholm mikael [dot] stokholm [at] snm [dot] ku [dot] dk], Department of Geosciences and Natural Resource Management (Geology Section), University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark. Benjamin Heredia [behe [at] geus [dot] dk] and Tonny B. Thomsen [tbt [at] geus [dot] dk], Geological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen K, Denmark.
Download PDF (2,76 Mb) Electronic appendix (60,07 Kb)Macrofossil studies of Lateglacial sediments from Regstrup, north-west Sjælland, Denmark.
Bennike, O., Claudi-Hansen, L., Magnussen, B. & Wiberg-Larsen, P. 2022. Macrofossil studies of Lateglacial sediments from Regstrup, north-west Sjælland, Denmark.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 39–51.
ISSN 2245-7070. https://doi.org/10.37570/bgsd-2022-70-04
Abstract: Studies of macrofossils indicate that the vegetation near Regstrup in north-west Sjælland, Denmark, from c. 13 600 to 13 500 cal. years BP was dominated by dwarf-shrub heaths. Betula pubescens (downy birch) arrived at c. 13 500 cal. years BP and became common after c. 13 200 cal. years BP. Open forests with B. pubescens and Populus tremula (aspen) dominated until c. 12 500 cal. years BP, indicating that an Allerød-type environment persisted for c. 350 years after the cooling at the onset of the Younger Dryas, which is dated to c. 12 850 years BP in ice cores from Green-land. Betula nana was common after c. 12 500 cal. years BP, indicating a return to a tundra-like landscape with dwarf-shrub heaths. The fauna included Rangifer taran-dus (reindeer), Castor fiber (Eurasian beaver) and possibly Lemmus lemmus (Norway lemming). The lake deposits contain remains of many species of aquatic plants and animals, including three species of fish. The flora and fauna indicate that the lake water was fairly nutrient-rich and alkaline.
Keywords: Lateglacial, Allerød, Younger Dryas, vegetation history, fauna history, Denmark.
Address: Ole Bennike [obe [at] geus [dot] dk], Geological Survey of Denmark and Greenland (GEUS), C.F. Møllers Allé 8, DK-8000 Aarhus C, Denmark. Lone Claudi-Hansen [lch@vestmuseum. dk], Museum Vestsjælland, Forten 10, DK-4300 Holbæk, Denmark. Betina Magnussen [betina [dot] magnussen [at] sund [dot] ku [dot] dk], GLOBE Institute, SUND, University of Copenhagen, Øster Voldgade 5-7, DK-1350 København K. Peter Wiberg-Larsen [pwl [at] ecos [dot] au [dot] dk], Institute for Ecoscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark.
Download PDF (6,74 Mb)An Eocene conger eel (Teleostei, Anguilliformes) from the Lillebælt Clay Formation, Denmark.
Carnevale, G., Schwarzhans, W., Schrøder, A.E. & Lindow, B.E.K. 2022. An Eocene conger eel (Teleostei, Anguilliformes) from the Lillebælt Clay Formation, Denmark.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 53–67. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-05-rev
File replaced 2022–04–22: Erroneous author name is now correct.
Original publication: https://doi.org/10.37570/bgsd-2022-70-05
Abstract: A conger eel (Anguilliformes, Congridae) is described from the lower Lutetian concretionary nodules of the Lillebælt Clay Formation exposed at Trelde Næs, eastern Jutland, based on two partially complete articulated cranial skeletons. One of the cranial specimens exhibits an otolith void from which a cast was taken, used by Schwarzhans (2007) to describe the extinct Pseudoxenomystax treldeensis, which is placed herein within the new genus Smithconger gen. nov. Smithconger treldeensis (Schwarzhans, 2007) is characterized by well-developed lateral processes on the frontals, supraoccipital crest absent, sphenotic spine rather large, anteriorly pointed and exposed on the flattened surface of the skull roof, otic bullae considerably reduced, maxilla almost straight and distally pointed, maxillary and dentary teeth numerous and arranged in multiple rows, dentary with slightly convex ventral profile, opercle with smooth posterior margin and subopercle short. The otoliths of Smithconger treldeensis show high dorsal rim, broad and deep dorsal depression, no ventral furrow, sulcus straight, shallow, centrally positioned with anteriorly reduced colliculum, and ostial channel at anterior tip of colliculum short, not reaching the predorsal rim. The otolith-based species Bathycongrus waihaoensis Schwarzhans, 2019 from the Kaiatan (Bartonian/Priabonian) of New Zealand is also assigned to the genus Smithconger. Smithconger is tentatively referred to the congrid subfamily Congrinae due to the lack of hypohyals in the hyoid bar. This new Eocene genus of conger eel shows a certain degree of similarity with the extant Bassanago. The diversity and relationships of other Eocene congrids is also briefly discussed.
Keywords: Anguilliformes, Congridae, Smithconger gen. nov., Eocene, Lutetian, Lillebælt Clay Formation, eastern Jutland.
Address: Giorgio Carnevale [giorgio [dot] carnevale [at] unito [dot] it], Dipartimento di Scienze della Terra, Uni-versità degli Studi di Torino, Via Valperga Caluso 35, I-10125 Torino, Italy. https://orcid.org/0000-0002-3433-4127. Werner Schwarzhans [wwschwarz [at] aol [dot] com], Ahrensburger Weg 103, D-22359 Hamburg, Germany; also Natural History Museum of Denmark, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark. https://orcid.org/0000-0003-4842-7989. Ane Elise Schrøder [aneelises [at] snm [dot] ku [dot] dk], Natural History Museum of Denmark, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark; also Fossil and Moclay Museum, Museum Mors, Skarrehagevej 8, Nykøbing Mors, DK 7900, Denmark. https://orcid.org/0000-0001-9371-400X. Bent Erik Kramer Lindow [lindow [at] snm [dot] ku [dot] dk], Natural History Museum of Denmark, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark. https://orcid.org/0000-0002-1864-4221.
Download PDF (2,32 Mb)Middle Cambrian (Miaolingian Series, Wuliuan Stage) molluscs and mollusc-like microfossils from North Greenland (Laurentia).
Peel, J.S. & Kouchinsky, A. 2022. Middle Cambrian (Miaolingian Series, Wuliuan Stage) molluscs and mollusc-like microfossils from North Greenland (Laurentia).
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 69–104. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-06
Abstract: Diverse assemblages of helcionelloid molluscs and mollusc-like microfossils are described from the upper Henson Gletscher Formation (Cambrian, Miaolingian Series, Wuliuan Stage) of Lauge Koch Land and western Peary Land, North Greenland (Laurentia). The fauna compares closely to an assemblage of similar age from the Coonigan Formation of Australia, although the latter is preserved as silica replicas while the North Greenland fossils are dominantly preserved as phosphatized internal moulds. These internal moulds often retain a detailed impression of the inner surface of the shell, with a fine pitted texture typically present. Prominent deep grooves on the sub-apical surface in the erect helcionellids Dorispira and Erugoconus, corresponding to ridges on the shell interior, seem to be associated with control of water flow through the mantle cavity. Well-developed shell pores, preserved as tubercles on the internal mould, are common in species of the laterally compressed Mellopegma. New taxa: Dorispira avannga sp. nov., Dorispira septentrionalis sp. nov., Dorispira tavsenensis sp. nov., Dorispira tippik sp. nov., Erugoconus acuminatus gen. et sp. nov., Scenella? siku sp. nov., Sermeqiconus gen. nov., Tavseniconus erectus gen. et sp. nov., Vendrascospira troelseni gen. et sp. nov., Vendrascospira frykmani gen. et sp. nov.
Keywords: Molluscs, Henson Gletscher Formation, Miaolingian Series (Wuliuan Stage), North Greenland, Laurentia.
Address: John S. Peel [john [dot] peel [at] pal [dot] uu [dot] se], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden. Artem Kouchinsky [artem. kouchinsky [at] gmail [dot] com], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden.
Download PDF (4,95 Mb)Holocene development of Brabrand Fjord, eastern Jylland, Denmark.
Bennike, O., Astrup, P.M., Odgaard, B.V., Pearce, C. & Wiberg-Larsen, P. 2022. Holocene development of Brabrand Fjord, eastern Jylland, Denmark.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 105–115. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-07
Abstract: The Brabrand Sø area west of Aarhus in eastern Jylland, Denmark, was deglaciated about 18 000 to 17 000 years ago. Coring in the present-day lake area revealed Early Holocene stream deposits overlain by marine deposits. The area was transgressed by the sea at c. 8500 cal. years BP and a 12 km long, narrow fjord was formed. In the beginning, the fjord housed a species-poor marine or brackish-water fauna with molluscs Hydrobia sp. (mudsnail), Littorina littorea (winkle), Mytilus edulis (blue mussel) and Cerastoderma sp. (cockle). This phase was followed by a phase during which the fjord housed a species-rich fauna that included Ostrea edulis (European flat oyster) and Ruditapes decussatus (palourde clam). During this phase the salinity and summer water temperatures were higher than in present day Aarhus Bugt and we also see evidence for strong bottom currents. This phase was probably characterised by a fairly large tidal amplitude. Two radiocarbon ages of O. edulis shells of c. 6250 and 6700 cal. years BP indicate that such conditions peaked during the period of the Ertebølle culture. The high-salinity phase was followed by a phase with a more species-poor fauna, this phase was also characterised by a high sedimentation rate – a feature seen in other fjords in the region. We suggest that the shift could be due to a decrease in tidal amplitude. Brabrand Fjord was eventually transformed into a lake due to land uplift and closure of the connection to Aarhus Bugt due to longshore sediment transport but the timing of the transition from fjord to lake is still unknown.
Keywords: Quaternary, Brabrand Sø, Littorina Sea, relative sea-level changes, tidal amplitude, Ostrea.
Address: Ole Bennike [obe [at] geus [dot] dk], Geological Survey of Denmark and Greenland (GEUS), Universitetsbyen 81, DK-8000 Aarhus C, Denmark. Denmark. Peter Moe Astrup [pma@ moesgaardmuseum.dk], Moesgaard Museum, Moesgård Allé 15, DK-8270 Højbjerg. Bent V. Odgaard [bvo [at] geo [dot] au [dot] dk] and Christof Pearce [christof [dot] pearce [at] geo [dot] au [dot] dk], Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C, Denmark. Peter Wiberg-Larsen [pwl [at] ecos [dot] au [dot] dk], Institute for Ecoscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark.
Download PDF (1,93 Mb)First occurrence of a frog-like batrachian (Amphibia) in the Late Triassic Fleming Fjord Group, central East Greenland.
Jésus, V.J.P., Mateus, O., Milàn, J. & Clemmensen, L.B. 2022. First occurrence of a frog-like batrachian (Amphibia) in the Late Triassic Fleming Fjord Group, central East Greenland.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 117–130. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-08
Abstract: During the Triassic, Batrachia diverged into ancestors of frogs (Salientia) and salamanders (Caudata). Fossils of Triassic batrachians are rare and found only in a few outcrops, such as the Middle Sakamena Formation of Madagascar (Induan). Only three Triassic taxa have been described, the two early frogs Triadobatrachus and Czatkiobatrachus and the early salamander Triassurus. Here we describe a right ilium, collected in 1991, attributed to the first batrachian from the Late Triassic Carlsberg Fjord Member (Ørsted Dal Formation, Fleming Fjord Group) in the Jameson Land Basin, located in central East Greenland. The fossil specimen only displays the proximal part of a right ilium, missing its shaft. After a thorough comparison with several clades (lizards, temnospondyls, salamanders and frogs), we consider the specimen as a lissamphibian sharing feature with salientians and anurans: squarish acetabular region, deeply concave acetabular surface, laterally projecting acetabular rim, flat mesial surface. It is the youngest Triassic specimen of Batrachia to date and one of the northernmost of the Late Triassic.
Supplementary file: Features potentially used for differentiating ilia of anurans and urodeles with updated nomenclature and specimen NHMD-154502, Triadobatrachus, Czatkobatrachus, Triassurus and Kokartus.
Keywords: Lissamphibia, frogs, salamanders, ilium, Late Triassic, Fleming Fjord Group.
Address: Valerian J. P. Jésus [valerian [dot] jesus [at] mail [dot] com], Museu da Lourinhã 2530-158 Lourinhã, Portugal. Octávio Mateus [omateus [at] fct [dot] unl [dot] pt], GEOBIOTEC, Departamento de Ciências da Terra, FCT-UNL Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Portugal & Museu da Lourinhã, Portugal. Jesper Milàn [jesperm [at] oesm [dot] dk], Geomuseum Faxe, Østsjællands Museum, Rådhusvej 2, DK-4640 Faxe, Denmark. Lars B. Clemmensen [larsc [at] ign [dot] ku [dot] dk], Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
Download PDF (3,63 Mb) Download supplementary file (14,65 Kb)Cutting through sponge and time – a new record of Koptichnus rasmussenae (trace fossil) from the Kerteminde Marl (middle Paleocene), Denmark.
Vallon, L.H. & Rindsberg, A.K. 2022. Cutting through sponge and time – a new record of Koptichnus rasmussenae (trace fossil) from the Kerteminde Marl (middle Paleocene), Denmark.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 131–137. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-09
Abstract: A new trace fossil, Koptichnus rasmussenae, was recently reported from the Cretaceous of Denmark. This burrow is thickly lined with cuboids that the tracemaker cut from siliceous sponges. A newly discovered specimen from the lower Selandian Kerteminde Marl, found in a loose boulder in the Gundstrup gravel pit (Fyn, Denmark), extends the stratigraphical range of this ichnotaxon from the previously known Coniacian to the middle Paleocene and demonstrates that this distinct behaviour of harvesting and shaping building material survived the K-Pg extinction event.
Keywords: domichnia, armoured burrow, sponge, Selandian, K-Pg extinction event.
Address: Lothar H. Vallon [kv [at] oesm [dot] dk], Geomuseum Faxe, Østsjællands Museum, Rådhusvej 2, 4640 Faxe, Denmark. Andrew K. Rindsberg [arindsberg [at] uwa [dot] edu], Dept. of Biological & Environmental Sciences, University of West Alabama, Livingston, AL 35470, USA.
Download PDF (1,89 Mb)Further holocephalian remains from the Hasle Formation (Early Jurassic) of Denmark.
Duffin, C.J. & Milàn, J. 2022. Further holocephalian remains from the Hasle Formation (Early Jurassic) of Denmark.
Bulletin of the Geological Society of Denmark, Vol. 70, pp. 139–149. ISSN 2245-7070.
https://doi.org/10.37570/bgsd-2022-70-10
Abstract: Oblidens bornholmensis, known from isolated upper posterior (palatine) and lower posterior (mandibular) tooth plates, was the first myriacanthid holocephalian to be described from the Hasle Formation (Pliensbachian, Early Jurassic) of Bornholm (Denmark). Further collecting in the Hasle Formation has yielded seven more specimens of myriacanthid tooth plates. Two mandibular tooth plates are assigned to Myriacanthus paradoxus, thereby extending both the geographical and stratigraphic range of the genus. In addition to new material of Oblidens bornholmensis, some distinctive myriacanthid palatine and mandibular tooth plates are described and left in open nomenclature. The Early Pliensbachian deposits of Bornholm preserve the most diverse myriacanthid fauna known to date.
Keywords: Bornholm, tooth plate, Holocephali, Myriacanthidae, Pliensbachian, Early Jurassic.
Address: Christopher J. Duffin [cduffin [at] blueyonder [dot] co [dot] uk], Earth Sciences Department, The Natural History Museum, Cromwell Road, London SW7 5BD, UK and 146, Church Hill Road, Cheam, Sutton, Surrey SM3 8NF, UK. Jesper Milàn [jesperm@oesm. dk], Geomuseum Faxe/Østsjællands Museum, Østervej 2, DK-4640 Faxe, Denmark.
Download PDF (8,18 Mb)