![]() claimed that the presumed Dakotaraptor furculae in fact represented a part of a turtle armour, the entoplastron of Axestemys splendida, a member of the Trionychidae. In 2015, a study by Victoria Megan Arbour e.a. Dakotaraptor had a furcula that was U- to V-shaped, similar to many other dromaeosaurids such as Velociraptor, and even the large spinosaurid theropod Suchomimus. Theropod wishbones are quite varied and often different from the strongly U-shaped furculae most modern birds possess. Like virtually all other theropods, Dakotaraptor possessed a furcula, or “wishbone”, as part of the shoulder girdle. The groove on its outer side towards the tip ends in a bone tunnel, a rare condition. The third claw too is keeled but is much smaller with a tip to joint length of seven centimetres and a curve length of nine centimetres. As these are the bony cores of the claws, they would have been covered in a keratinous sheath that extended the "nail" and ended in a sharp tip. The flexor tubercle on the third claw of the foot is almost non-existent, very reduced in size compared to other dromaeosaurids, suggesting a more minimized use of that claw. ![]() Dakotaraptor has a flexor tubercle that is larger relative to overall claw size than it is in other discovered dromaeosaurids, potentially giving it the strongest slashing strength of any known member of this group. The flexor tubercle, a large bump near the base, served as an attachment site for flexor muscles - the larger it was, the greater the slashing strength. The claw is transversely flattened and has a droplet-shaped cross-section. This equals 29% of the length of the thighbone compared to 23% with Deinonychus. It is large and robust with a diameter of sixteen centimetres and a length of twenty-four centimetres measured along the outer curve. The foot claws of Dakotaraptor include a typical dromaeosaurid raptorial second claw, or "sickle claw", which was used for killing or holding down prey. The metatarsus has an estimated length of thirty-two centimetres, which makes it rather long relative to the remainder of the hindlimb. The top of the calcaneum has but a small contact facet for the calf bone, indicating that this fibula must have had a very narrow lower end. The astragalus and calcaneum, the upper ankle bones, are fused just as in Bambiraptor. Its fibular crest ends in a hook-shaped process pointing to above, a condition that is unique in the entire Theropoda. The shinbone's cnemial crest has a sharp corner pointing to the front. It is 22% longer than the thighbone, indicating a good running capability. The holotype shinbone is with a length of 678 millimetres the longest dromaeosaurid tibia known. ![]() To the contrary the shinbone is rather elongated. It is relatively shorter and more lightly built than that of Utahraptor. The length of the thighbone is 558 millimetres. Dakotaraptor more closely resembles the agile, springy smaller dromaeosaurids and would have been well-suited at running and pursuit predation. Overall, the hindlimb is built lightly and with long elements, contrary to the robust, stocky hind limbs of Utahraptor. In addition to this, the two genera are very different proportion-wise with Dakotaraptor being less heavily built and better adapted for speed than the more powerful Utahraptor.Īpart from the large size, the description of 2015 indicated some additional distinguishing traits. Utahraptor was 7 metres (23 feet) and 500 kg (1,100 lbs), while Dakotaraptor was 6 metres (19.6 feet) and 453 kg (1,000 lbs). The status of Dakotaraptor as a chimaera, casting doubt on this placement as too basal due to the potential composite nature of the taxon.Ī common misconception is that Dakotaraptor has surpassed Utahraptor as the largest dromaeosaurid, but this is untrue. Dakotaraptor is potentially a chimaeric genus of large dromaeosaurid theropod.
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