- Dromaeosauroides
-
Dromaeosauroides
Temporal range: Early Cretaceous, 140 Ma
Holotype tooth, Geological Museum (Copenhagen) Scientific classification 
Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Dinosauria Order: Saurischia Suborder: Theropoda Infraorder: †Deinonychosauria Superfamily: †Dromaeosauroidea Family: †Dromaeosauridae Genus: †Dromaeosauroides
Christiansen & Bonde, 2003Species: †D. bornholmensis
Christiansen & Bonde, 2003Dromaeosauroides (meaning "Dromaeosaurus-like") is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous of Denmark.
In the southwest of the island of Bornholm, layers of the Early Cretaceous Jydegaard Formation surface, dating to the late Berriasian age, about 140 million years ago and consisting of marine sediments, deposited in a lagoon. From the A/S Carl Nielsen site, a gravel and sand pit in the Robbedale valley, microfossils emerged since the 1980s. In the late 1990s an activation programme, "Project Fossil", was started for unemployed youth having to sieve the sand in search of bone fragments in exchange for a welfare benefit. In September 2000 palaeontologists Per Christiansen and Niels Bonde providing an excavation field course, visited the site with a group of students from Copenhagen, accompanied by a camera team of the Danish television.[1] On that occasion 18-year-old geology student Eliza Jarl Estrup found a theropod tooth,[2] the first dinosaur find on Danish territory.[3]
The type species, Dromaeosauroides bornholmensis, was named and described by Christiansen and Bonde in 2003, as the first Danish dinosaur. The generic name combines the name of Dromaeosaurus with Greek ~ides, "in the form of", referring to the resemblance between the taxa. The specific name refers to Bornholm.[4]
The holotype specimen, MGUH DK 315, was uncovered in a sand layer, three metres above the Neomiodon Bed of the Tornhøj Member of the Jydegaard Formation. It consists of a tooth crown; the shape and length of the tooth indicates that it was placed in the front part of the lower jaw.[5]
Hypothetical restoration, based on related genera
The tooth crown is 21 millimetres long, about a quarter longer than equivalent teeth of Dromaeosaurus, from which a body length for Dromaeosauroides of three metres was estimated. The tooth is relatively elongated, slightly flattened with an oval cross-section, and recurved with a sudden backwards bend.[6] The front and hindmost parts of the tooth, the cutting edges, are finely serrated, and the front part has been strongly worn; the tooth was probably shed when the animal was alive. The square shape of the denticles and the distance between the serrations of which about six are placed per millimetre, are only known from dromaeosaurids.[7]
In August 2008 a second dromaeosaurid tooth was reported by ranger Jens Kofoed. "Project Fossil" had been terminated in 2004, but the site was subsequently used as a tourist attraction providing day trips to families digging up fossils.[8] The second tooth, also from the anterior dentary, is fifteen millimetres long and has been provisionally referred to Dromaeosauroides by Bonde. The two dromaeosaurid teeth and a titanosaur tooth found by a welfare recipient in 2002, were declared Danish national heritage, Danekræ, meaning they cannot be legally sold to a private collection or exported.
Dromaeosauroides was by the describers assigned to the Dromaeosaurinae within the Dromaeosauridae. It might be the only known true dromaeosaurid from the Lower Cretaceous of Europe, depending on the identity of Nuthetes.
References
- ^ Bornholmske Dinosaurer TV2, Bornholm
- ^ Eliza Jarl Estrup, 2007, "Jurassic Park Denmark", Scient, 4(1): 12-14
- ^ Danish Dinosaur
- ^ Christiansen P. and Bonde N., 2003, "The first dinosaur from Denmark", Neues Jahrbuch der Geologie und Palaeontologie Abhandlungen 227(2): 287-299
- ^ New dinosaurs from Denmark = Nouveaux dinosaures du Danemark
- ^ Bonde N. and Christiansen P., 2003, "New dinosaurs from Denmark", Comptes Rendus Palevol. 2: 13-26
- ^ Bonde, N., Andersen, S., Hals, N., and Jakobsen, S.T. (2008). Danekræ - Danmarks bedste fossiler. Copenhagen: Gyldendal. 224 pp.
- ^ Katrine Barslev, 2008, "Tand fra dinosaur fundet på Bornholm", Kristeligt Dagblad, 15 augustus 2008
External links
Categories:- Dromaeosaurs
- Dinosaurs of Europe
- Cretaceous dinosaurs
- Theropod stubs
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