Albertadromeus
| Albertadromeus | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Upper Cretaceous ( Campanium ) | ||||||||||||
| approx. 76 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Albertadromeus | ||||||||||||
| Brown et al., 2013 | ||||||||||||
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Albertadromeus is a genus of ornithopods . The representatives of their only species, Albertadromeus syntarsus, were around 1.6 m long, two-legged dinosaurs and ate plants. They livedon the east coast of the Western Interior Seaways during the Late Cretaceous (around 76 mya ). The fossil remains of the genus were found during excavations in Canada's Milk River Valley in 2009and come from the Oldman Formation there . It was first described in 2013 by a research group led by Caleb Brown as a new genus and species. Based on phylogenetic analyzes, the authors placed the genus in the taxon Orodrominae , where it is positioned as the closest relative of Orodromeus and Zephyrosaurus .
features
The fossil finds of Albertadromeus syntarsus only allow direct conclusions to be drawn about the pelvic girdle and the back of the spine. The reconstruction of other features is based on comparisons with closely related taxa. If one takes the proportions of the well-handed down Orodromeus makelei as a basis, a total length of 1.6 m and a weight of 13 kg can be estimated for Albertradromeus syntarsus . Albertadromeus is characterized by a combination of various osteological features: the lower third of the fibula is fused with the tibia . The tibia has two distinct extensions at the upper end and is provided with a strongly pronounced front edge.
ecology
Although no fossil material has come down to us from the skull or anterior running apparatus of Albertadromeus , since his closest relatives were all herbivores , Albertadromeus may also have fed on herbivores.
Fossil Material, Distribution, and Stratigraphy
Albertadromeus' fossil material comes from a single individual and is held in the Royal Tyrrell Museum of Paleontology under inventory number TMP 2009.037.0044. It includes some isolated vertebrae of the back and tail spine with ossified tendons , leg and foot bones. They were uncovered by David Evans during excavations on the Milk River in Canada and come from the upper section of the Oldman Formation . Based on its polarization , the find layer is dated to an age of around 76 million years and thus to the Campanium . At the time, it was found on the west coast of the Western Interior Seaways , which divided North America into Laramidia and Appalachia in the Cretaceous Period .
Systematics
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| Systematic position of Malawania according to Brown et al. (2013). The genus is the closest relative of Orodromeus and Zephyrosaurus . |
The find from the Oldman formation was used by Caleb M. Brown , David Evans, Michael Ryan and Anthony Russell as a holotype for their description of the genus Albertadromeus and the species Albertadromeus syntarsus . The generic name is made up of " Alberta ", the Canadian province of the place where it was found, and the Greek "dromeas" ( δρομέας , Latin for "dromeus") for runners. The epithet syntarsus (Greco-Latin for "united barrel") of the species derived the authors from the morphology of the fused lower leg bones.
On the basis of a matrix previously worked out by Brown and colleagues, the authors classified Albertadromeus in a cladistic analysis in a clade with Zephyrosaurus and Orodromeus . The exact sister group relationships between the three genera were not resolved.
swell
literature
- Caleb Marshall Brown, Clint A. Boyd, Anthony P. Russell: A new basal ornithopod dinosaur (Frenchman Formation, Saskatchewan, Canada), and implications for late Maastrichtian ornithischian diversity in North America . In: Zoological Journal of the Linnean Society . Vol. 163, No. 4, 2011, ISSN 0024-4082 , pp. 1157-1198, doi : 10.1111 / j.1096-3642.2011.00735.x .
- Caleb Marshall Brown, David C. Evans, Michael J. Ryan, Anthony P. Russell: New data on the diversity and abundance of small-bodied ornithopods (Dinosauria, Ornithischia) from the Belly River Group (Campanian) of Alberta . In: Journal of Vertebrate Paleontology . Vol. 33, No. 3, 2013, ISSN 0272-4634 , pp. 495-520, doi : 10.1080 / 02724634.2013.746229 .