Hahaaaa early-morning tyrants
Dryptosaurus aquilunguis (née Laelaps) has been relegated to the perhaps unfortunate status of being a source of dinosaur trivia and not much else. It was among the first North American dinosaurs, described by Cope in 1866 as Laelaps. This name was found to be preoccupied by a bug (an unfortunate trend in the history of dinosaur palaeontology), and so Cope's arch-rival Othniel Charles Marsh swooped in to coin a new generic name for the theropod, which briefly became a sort of wastebasket taxon for a number of North American theropod material.
For a long time primarily noted only for its naming debacle and status as the only predatory dinosaur of the eastern United States, its importance in the tyrannosaur family tree has been re-evaluated with the description of the related Appalachiosaurus in 2005. Dryptosaurus lived in the Maastrichtian stage of the Upper Cretaceous, 67 Ma at the same time that its distant cousin Tyrannosaurus was establishing itself as the arch-predator of the west.
Dryptosaurus is preserved in what were once coastal, estuarine lowlands, along with Hadrosaurus, the first discovery of what would prove to be a widespread and diverse group of herbivorous dinosaurs.