New Dinosaur Species in Mongolia Upends Therizinosaur Digit Counts

In a remarkable discovery, paleontologists have identified a new species of therizinosaur in Mongolia, known as Duonychus tsogtbaatari, dating back 90 million years. Unearthed at a construction site in the Gobi Desert in 2012, its study revealed that this dinosaur broke from the norm by boasting only two fingers instead of the usual three found in therizinosaurs. This striking discovery was made with the help of a claw, larger than any found before, featuring a preserved keratin sheath common in modern fingernails but rare in fossils. Yoshitsugu Kobayashi from Hokkaido University led the research, highlighting that Duonychus was the first known therizinosaur to evolutionarily discard a digit, a trait it shares with only five theropod groups, such as the famous Tyrannosaurus. Its claws, nearly 30 centimeters long, suggest an adaptation for vegetation grasping, hinting at its herbivorous diet and providing new insights into dinosaur evolution. The loss of the third digit allowed for a strong, flexible grip to pull down branches, a hypothesis supported by the stiffness found in its joints. The find provides a rare, tangible glimpse into prehistoric life, offering a new perspective on dinosaur behavior and evolution. As Professor Darla Zelenitsky emphasized, the preservation of such fossilized structures opens a fresh window into past ecosystems. My commentary on this discovery points to the relentless excitement and unpredictability in paleontology. Each find, like Duonychus's claw, has the potential to reshape understanding of dinosaur evolution and behavior. The remarkably preserved claw adds a visceral dimension to the research, evoking appreciation for the scientists dedicated to bridging the eons between us and these ancient creatures. This discovery also underscores the critical importance of conservation at fossil sites, ensuring future finds are preserved and studied. The study, a collaborative effort with insights from teams in Japan, Canada, and the United States, has been published in iScience, continuing the conversation on dinosaurioplayful research and the intricate dance of evolutionary adaptations.