Fossils discovered during the construction of a water pipeline in Mongolia’s Gobi Desert have revealed an unusual dinosaur characterized by a formidable pair of curved claws. This newly recognized species, named Duonychus tsogtbaatari, is part of the therizinosaurs, a distinctive group of herbivorous theropods. However, it distinguishes itself from its relatives by possessing two-fingered hands, a feature it shares with the notorious Tyrannosaurus rex. Duonychus measured approximately 10 feet in length and weighed around 575 pounds, existing during the Cretaceous Period, approximately 90 to 95 million years ago. Unlike its therizinosaurs counterparts, which typically had three fingers, Duonychus had only two fingers, each ending in a formidable claw measuring about a foot long. Notably, one of the fossils preserved its keratin sheath, indicating that the claw was over 40% longer than the bone beneath it. Although therizinosaurs were primarily herbivorous, their large claws may have had various uses, such as pulling down branches for feeding. The identification of Duonychus contributes to the expanding catalog of theropod dinosaurs that have independently developed two-fingered hands, drawing a fascinating comparison to T. rex, whose small yet powerful arms continue to intrigue paleontologists.
