Tanycolagreus

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Tanycolagreus
Temporal range: Upper Jurassic
153–150 mya
Tanycolagreus.jpg
Tanycolagreus holotype, North American Museum of Ancient Life, Utah.
Scientific classification
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Tanycolagreus

Carpenter et al, 2005

Tanycolagreus is a genus of coelurosaur theropod from the Upper Jurassic of North America.

The fossil holotype was donated to science by an anonymous benefactor. It is part of the collection of Thanksgiving Point Institute, and displayed in the North American Museum of Ancient Life at Lehi, Utah. It includes an incomplete skull and mandible (lower jaws) and much of the postcranial skeleton, i.e. the parts behind the head. The size of this specimen suggests a size in life of about 3.3 meters (11 feet) long.

Habitat[change | change source]

The fossil was found in the Morrison Formation, where originally there was a great variety of life. This environment a savannah with many rivers. Along the rivers were conifer forests, with ginkgos, cycads, tree ferns, and horsetails rushes.

Insects were very similar to modern species, with termites building 30 m (100 ft.) tall nests. Along the rivers, there were fish, frogs, salamanders, lizards, crocodiles, turtles, pterosaurs, crayfish, clams, and monotremes (prototherian mammals, the largest of which was about the size of a rat). The dinosaurs were most likely along the rivers as well. Hundreds of dinosaur fossils have been discovered.

According to radiometric dating, the Morrison Formation dates from 156.3 ± 2 million years old (mya) at its base,[1] to 146.8 ± 1 mya at the top,[2] so it lasted just under 10 million years.

Phylogeny[change | change source]

Carpenter and his co-workers said that this genus most closely resembles Coelurus, though it has some more "primitive" features.[3] Although a 2007 analysis suggested it was a basal Tyrannosaur,[4] later work showed once again its basal position in the Coelurosauria.[5]

References[change | change source]

  1. Trujillo K.C; Chamberlain K.R. and Strickland A. 2006. "Oxfordian U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic correlations". Geological Society of America Abstracts with Programs 38 (6): 7. 
  2. Bilbey S.A. 1998. "Cleveland-Lloyd Dinosaur Quarry: age, stratigraphy and depositional environments". In Carpenter K; Chure D. and Kirkland J.I. (eds) (eds.). The Morrison Formation: an interdisciplinary study. Modern Geology 22. Taylor and Francis Group. pp. 87–120. ISSN 0026-7775.CS1 maint: Uses editors parameter (link)
  3. Carpenter K; Miles C. and Cloward K. 2005. New small theropod from the Upper Jurassic Morrison Formation of Wyoming. In Carpenter K. 2005. The carnivorous dinosaurs. Indiana University Press: 23-48.
  4. Senter P. 2007. A new look at the phylogeny of Coelurosauria (Dinosauria: Theropoda). Journal of Systematic Palaeontology, 5(4): 429-463
  5. Rauhut O.W.M; Milner A.C. and Moore-Fay S. 2010. Cranial osteology and phylogenetic position of the theropod dinosaur Proceratosaurus bradleyi (Woodward 1910) from the Middle Jurassic of England. Zoological Journal of the Linnean Society 158(1): 155-195