Dakotaraptor
- Name meaning: Dakota Raptor
- Length: 4.8-5.7 m (15-17 feet)
- Weight: 220+ kg
- Height: 1.7-1.8 m (5-6 feet)
- Time Period: 68-65 mya
- Habitat: North America
- Speed: 40+ mph
- Sickle Claw Size: 24 cm at the outer curve
Dakotaraptor steini is a species of large carnivorous theropod dromaeosaurid dinosaur from the Late Cretaceous of North America.The first fossils of Dakotaraptor were found in South Dakota, USA, in 2005. In 2015, the genus Dakotaraptor received its name, meaning "plunderer of Dakota", when the type species Dakotaraptor steini was described. The fossils contain an incomplete skeleton without a skull and some individual bones. They have been found in the Maastrichtian-age Hell Creek Formation, dated to the very end of the Cretaceous period, making Dakotaraptor one of the last surviving dromaeosaurids.
Dakotaraptor was about five to six metres long, which makes it one of the largest dromaeosaurids known. It had long arms. One of the lower arm bones shows bumps for feathers, proving that Dakotaraptor had wings. It also had long rear legs with a very large sickle claw on the second toe. The claw could be used to kill relatively large plant-eating dinosaurs. Dakotaraptor lived in the same time and area as Tyrannosaurus rex.
Apart from the large size, the description of 2015 indicated some additional distinguishing traits. On the fourth foot claw, the boss that serves as an attachment for the tendon of the flexor muscle is reduced in size. The "blood groove" on the outer side of the fourth claw of the foot, towards the tip is fully enclosed over half of its length, forming a bony tubular structure. The second and third claws of the foot have sharp keels at their undersides. The second foot claw, the "sickle claw", equals 29% of the thighbone length. On the shinbone, the crista fibularis, the crest that contacts the calfbone, is long and lightly built with a height that does not exceed 9% of the crest length. The upper edge of this crest ends in a hook. On the second metacarpal, of the two condyles that contact the finger, the inner one is almost as large as the outer one. The outer side of the second metacarpal has but a shallow groove for the ligament that connects it to the third metacarpal. When the arm is seen in a flat position, of the second metacarpal the edge between the wrist joint and the upper shaft is straight in top view. The teeth have fifteen to twenty denticles per five millimetres on the rear edges and twenty to twenty-seven denticles on the front edges.
Because of its co-existence with Tyrannosaurus, the Dakotaraptor most likely took upon the niche of the medium sized predator, the only other competitor in that niche was probably Nanotyrannus, wether it was a separate species or a Tyrannosaurus juvenile. It almost certainly hunted in packs much like their more famous relatives such as Velociraptor and Deinonychus. Their main prey would've probably been Hadrosaurs such as saurolophus and Edmontosaurus.
Dakotaraptor was about five to six metres long, which makes it one of the largest dromaeosaurids known. It had long arms. One of the lower arm bones shows bumps for feathers, proving that Dakotaraptor had wings. It also had long rear legs with a very large sickle claw on the second toe. The claw could be used to kill relatively large plant-eating dinosaurs. Dakotaraptor lived in the same time and area as Tyrannosaurus rex.
Apart from the large size, the description of 2015 indicated some additional distinguishing traits. On the fourth foot claw, the boss that serves as an attachment for the tendon of the flexor muscle is reduced in size. The "blood groove" on the outer side of the fourth claw of the foot, towards the tip is fully enclosed over half of its length, forming a bony tubular structure. The second and third claws of the foot have sharp keels at their undersides. The second foot claw, the "sickle claw", equals 29% of the thighbone length. On the shinbone, the crista fibularis, the crest that contacts the calfbone, is long and lightly built with a height that does not exceed 9% of the crest length. The upper edge of this crest ends in a hook. On the second metacarpal, of the two condyles that contact the finger, the inner one is almost as large as the outer one. The outer side of the second metacarpal has but a shallow groove for the ligament that connects it to the third metacarpal. When the arm is seen in a flat position, of the second metacarpal the edge between the wrist joint and the upper shaft is straight in top view. The teeth have fifteen to twenty denticles per five millimetres on the rear edges and twenty to twenty-seven denticles on the front edges.
Because of its co-existence with Tyrannosaurus, the Dakotaraptor most likely took upon the niche of the medium sized predator, the only other competitor in that niche was probably Nanotyrannus, wether it was a separate species or a Tyrannosaurus juvenile. It almost certainly hunted in packs much like their more famous relatives such as Velociraptor and Deinonychus. Their main prey would've probably been Hadrosaurs such as saurolophus and Edmontosaurus.