Resolving the long-standing enigmas of a giant ornithomimosaur Deinocheirus mirificus. 2014. Lee, Y.-N., et al. Science.
a, MPC-D 100/127. b, MPC-D 100/128. c, Composite reconstruction of MPC-D 100/127 with a simple proportional enlargement of MPC-D 100/128.
Abstract: The holotype of
Deinocheirus mirificus was collected by the 1965 Polish–Mongolian Palaeontological Expedition at Altan Uul III in the southern Gobi of Mongolia. Because the holotype consists mostly of giant forelimbs (2.4 m in length) with scapulocoracoids, for almost 50 years
Deinocheirus has remained one of the most mysterious dinosaurs. The mosaic of ornithomimosaur and non-ornithomimosaur characters in the holotype has made it difficult to resolve the phylogenetic status of
Deinocheirus.
Here we describe two new specimens of
Deinocheirus that were discovered in the Nemegt Formation of Altan Uul IV in 2006 and Bugiin Tsav in 2009. The Bugiin Tsav specimen (MPC-D 100/127) includes a left forelimb clearly identifiable as
Deinocheirus and is 6% longer than the holotype. The Altan Uul IV specimen (MPC-D 100/128) is approximately 74% the size of MPC-D 100/127.
Cladistic analysis indicates that Deinocheirus is the largest member of the Ornithomimosauria; however, it has many unique skeletal features unknown in other ornithomimosaurs, indicating that
Deinocheirus was a heavily built, non-cursorial animal with an elongate snout, a deep jaw, tall neural spines, a pygostyle, a U-shaped furcula, an expanded pelvis for strong muscle attachments, a relatively short hind limb and broad-tipped pedal unguals.
Ecomorphological features in the skull, more than a thousand gastroliths, and stomach contents (fish remains) suggest that
Deinocheirus was a megaomnivore that lived in mesic environments.
In 1866, the Peabody Museum of Natural History was founded with a gift from George Peabody. The same year his nephew, O.C. Marsh (Oct. 29, 1831 - Mar. 18, 1899), was also named its Professor of Paleontology, the first such appointment in the United States. In 1869 Marsh used the inheritance from his uncle to start to amass large collections of vertebrate fossils. He went on to long and successful career as a vertebrate paleontologist, most of which was spent feuding with is rival, E.D.Cope.
and extended the knowledge of Canadian geology. Dawson was born and raised in Pictou, Nova Scotia, where the many sandstone and coal formations provided fertile ground for his first scientific explorations, which culminated in the publication of Acadian Geology. He made many important discoveries of fossil life, great and small. These included fossil plants, trackways of lowly invertebrates, footprints, skeletons of reptiles and amphibians, millipedes and the earliest land snails. When the famous geologist Charles Lyell visited coal deposits in Pictou, Dawson acted as his guide.
Nova Scotia. They discovered the remains of some of the earliest known reptiles, Hylonomus lyelli, along with other rare fossils, propelling this part of the world into the international spotlight.
understanding of intercontinental migrations of animal species in past geological times. Simpson specialized in early fossil mammals, leading expeditions on four continents and discovering in 1953 the 50-million-year old fossil skulls of dawn horses in Colorado.
