Early Jurassic selachians from the Hasle Formation on Bornholm, Denmark
Jan Rees
A selachian fauna from the early Pliensbachian (Uptonia jamesoni to Prodactylioceras davoei zones) is recorded from the Hasle Formation on the island of Bornholm. Three hybodont sharks, Hybodus reticulatus, H. delabechei and Lissodus hasleensis sp. n., and three neoselachians, Synechodus occultidens, Paraorthacodus sp. and Agaleus dorsetensis, are recognized in the fauna. The enameloid ultrastructure of teeth of A. dorsetensis was examined and found to be comprised of at least two layers, confirming a neoselachian affinity, based on the overall tooth morphology. The palaeogeographical and stratigraphical records of the previously described species are extended. Pliensbachian selachian faunas are not well investigated and the described species in the Hasle fauna are all known from Sinemurian deposits elsewhere.
Key words: Selachians, hybodonts, neoselachians, palaeobiogeography, palaeoecology, Pliensbachian, Early Jurassic, Bornholm, Denmark.
Jan Rees [Jan.Rees@geol.lu.se], Department of Geology, Lund University, Sölvegatan 13, SE-223 62 Lund, Sweden.
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