Made of keratin (the same material as fingernails), the sheath reveals that the claw itself was much longer than the underlying bones. It is the largest claw of its kind found fully preserved in this way,

Scientists have discovered a new species of dinosaur in Mongolia's Gobi Desert. Called Duonychus tsogtbaatari, the dinosaur has two foot-long clawed fingers on each hand, one fewer than its fellow therizinosauria.