Dryptosaurus ( ) is a genus of tyrannosauroid that lived approximately 67 million years ago (mya) during the latter part of the Cretaceous period, New Jersey. Dryptosaurus was a large, bipedal, ground-dwelling carnivore, that grow up to long and weigh up to . Although largely unknown now outside of academic circles, a famous painting of the genus by Charles R. Knight made Dryptosaurus one of the more widely known dinosaurs of its time, in spite of its poor fossil record. First described by Edward Drinker Cope in 1866 and later renamed by Othniel C. Marsh in 1877, Dryptosaurus is among the first theropod dinosaurs known to science. Discovery and species Prior to the discovery of Dryptosaurus in 1866, New World theropods were known only from some isolated theropod teeth discovered in Montana by Joseph Leidy in 1856. The discovery of this genus gave North American paleontologists the opportunity to observe an articulated, albeit incomplete, theropod skeleton. During the 19th century, this genus unfortunately became a wastebasket taxon for the referral of isolated theropod elements from across North America given that tyrannosauroids were not recognized as a distinct group of large theropods in the late 19th century, and numerous theropod species were assigned to it (often as Lælaps or Laelaps) only to be later reclassified. The genus name Dryptosaurus, means "tearing lizard", and is derived from the Greek words "dryptō" (), meaning "I tear" and "sauros" () meaning "lizard". The specific name aquilunguis, is derived from the Latin for "having claws like an eagle's", a reference to the claws on its three-fingered hand. E. D. Cope (1866) published a paper on the specimen within a week of its discovery, and named it Laelaps aquilunguis at a meeting of the Academy of Natural Sciences in Philadelphia. "Laelaps", which is derived from the Greek for "hurricane" or "storm wind", was also the name of a dog in Greek mythology that never failed to catch what it was hunting. Laelaps gained popularity as both a poetic and evocative name and became one of the first dinosaurs described from North America, following Hadrosaurus and Trachodon. Later it was discovered that the name Laelaps had already been given to a genus of mite, and Cope's lifelong rival O.C. Marsh changed the name in 1877 to Dryptosaurus. The type species is Dryptosaurus aquilunguis. Brusatte et al. (2011) noted that well-preserved, historic casts of most of the type