Dromaeosaurus (Running lizard)
Dromaeosaurus (Running lizard)
Named By : William Diller Matthew and Barnum Brown – 1922
Diet : Carnivore
Size : Estimated 2 meters long
Type of Dinosaur : Small Theropod
Type Species : D. albertensis (type)
Found in :Canada, Alberta. USA, Montana
When it Lived : Late Cretaceous, 76-74 million years ago
Dromaeosaurus (/,droUmi@’so:r@s, mioU(/ “swift running lizard”) is a genus belonging to the dromaeosaurid theropod dinosaurs which was present during the Late Cretaceous period (middle late Campanian) that was between 80-69 million years ago in Alberta, Canada and the western United States. The species of the type is Dromaeosaurus albertensis, first identified in 1922 by William Diller Matthew and Barnum Brown in 1922. Its fossils were discovered inside the Dinosaur Park Formation. Teeth that belong to this genus were discovered inside the Prince Creek Formation. Dromaeosaurus is the genus that defines the species from the two genera Dromaeosauridae and Dromaeosaurinae which includes many genera that share the same characteristics as Dromaeosaurus including Dakotaraptor which is its closest cousin. Dromaeosaurus was a large and robust animal in comparison to other dromaeosaurs with similar dimensions, such as Velociraptor.
Despite being the subject of a lot of interest in popular literature on dinosaurs and the utilization of a fully mounted skeleton in museums across all over the globe, Dromaeosaurus has been a mystery to fossils. The making of the famous model of the Tyrrell Museum Tyrrell Museum was only made possible by the information gleaned from other dromaeosaurids which have been discovered recently.
The first Dromaeosaurus remains were found through paleontologist Barnum Brown on an expedition in 1914 towards Red Deer River on behalf of the American Museum of Natural History. The area in which these bones were found currently forms part of Dinosaur Provincial Park in Alberta, Canada. The find, called holotype AMNH 5356, comprised the skull’s partial size of 24cm (9+1/2 inch) in length and a mandible, as well as two hyoids, a metacarpal and foot bones. The skull was missing most of the upper snout. A few other skull fragments, including around thirty teeth that are not found, were discovered later within Alberta as well as Montana.
In 1922, William Diller Matthew and Brown classified and named the species in Dromaeosaurus: Dromaeosaurus albertensis. The name itself originates of the Greek dromeus (dromeus) which means “runner” while sauros (sauros) meaning lizard. The particular term, “albertensis”, refers to Alberta.
Seven other kinds of Dromaeosaurus were identified as: Dromaeosaurus laevifrons (Cope 1876) Matthew & Brown 1922; Dromaeosaurus cristatus (Cope 1876) Matthew & Brown 1922 (Troodon); Dromaeosaurus? gracilis (Marsh 1888) Matthew & Brown 1922; Dromaeosaurus explanatus (Cope 1876) Kuhn 1939; Dromaeosaurus minutus (Marsh 1892) Russell 1972 (an alvarezsaurid); Dromaeosaurus falculus (Cope 1876) Olshevsky 1979 and Dromaeosaurus mongoliensis (Barsbold 1983) Paul 1988 (Adasaurus). The majority of them are based upon fragmentary data that was part of other genera, and smaller than the one of Dromaeosaurus albertensis. The ones which haven’t been reclassified, are considered dubia nominae today. However, it is becoming evident this Dromaeosaurus albertensis is more rare in its environment than other theropods of a smaller size however this was actually the first dinosaur for which a cranial tissue that was reasonably well-constructed was discovered. The Genus Chirostenotes was thought to be identical to Dromaeosaurus at an earlier time.
Dromaeosaurus was a carnivore of medium size with a length of 2 meters (6 7 inches) in length, and 15 kg (33 lbs) of weight. Its mouth was brimming with sharp teeth. It also had sharply curved “sickle claw” on each foot. It was a part of the Campanian phase in the Late Cretaceous. But, some fragments of remains like teeth that could be part of this genus were discovered in early Maastrichtian period Hell Creek and Lance Formations which date back to the age of 66 millennia ago. Teeth have also been discovered inside the Aguja Formation.
Dromaeosaurus was known for its robust skull, with a deep snout. Its teeth were rather big and were shaped as an elongated cone, with enamel that covered the crown. There were only nine teeth per maxilla. Dromaeosaurus also was home to a vein located at the rear of the head, called the dorsalis venacapitis that drains the neck muscles of the front by a long canal that extended across the posterior of the brain. Its Meckelian groove in Dromaeosaurus is quite narrow and doesn’t have any depth.