A work that I started back this spring, but finished quite recently. This is a Duonychus tsogtbaatari, a therizinosaurid from the Late Cretaceous (Cenomanian-Coniacian) Bayanshiree Formation (Mongolia). Its partial postcranial skeleton, which includes some vertebrae and ribs, partial shoulder and pelvic girdles, and both forelimbs, was found in 2012. The remains belonged to an immature individual weighing about 260 kilograms. A characteristic feature of the Duonychus is a didactyl manus with a strongly reduced third metacarpal bone (hence the generic name of the dinosaur). The keratinous sheath of one of the claws has been preserved, extending it by more than 40 percent. Mobility in the Duonychus' elbow joint was limited, as was the case with the first phalanx of the thumb, but the claw joint could bend almost perpendicular to the previous bone. The latter trait is not observed in other two-fingered theropods and, presumably, helped the animal to grab the branches of plants when feeding.
Adobe Photoshop, 2025.











