The sun is hot on Deinocheirus’ back. The morning had passed quickly and uneventfully, and now Deinocheirus wades in a shallow stream, partly to find food, but mostly to cool itself down. Its hoof-like claws on its toes keep it from sinking in the mud.
The dinosaur lowers its head towards the water, and with its duck-like bill, Deinocheirus sucks up the soft plants that hide at the bottom of the stream. The round, flat beak is covered in keratin, which strengthens it. Deinocheirus uses its big tongue inside its deep lower jaw to push the vegetation down its gullet. Deinocheirus has no teeth, so to help grind up its meal, Deinocheirus picks up a couple smooth stones and swallows them whole. These gastroliths will help it digest food over time.
A small fish swims near Deinocheirus, to pick at the plants. Not wanting to miss an opportunity, Deinocheirus reaches out for the fish with its eight-foot long arms. The fish tries to dart out of the way, but Deinocheirus uses its claws to catch the prey. The giant dinosaur has a weak bite, so it cannot simply take a chunk out of its meal. Instead, Deinocheirus scoops up the fish from its hands with its tongue and swallows.
Now, after a light snack and a chance to cool down, Deinocheirus wades out of the water and looks for more vegetation to eat. At 35 feet long and weighing 6 tons, it lumbers out of the water on its two muscular legs and heads for a patch of trees full of fresh, mouth-watering leaves.
Deinocheirus pulls down the branches with its claws and plucks off its food. With its long, ostrich-like neck, it can reach almost all the vegetation. As it eats, Deinocheirus tail feathers wag happily. It is so engrossed in its food it almost doesn’t see the hungry Tarbosaurus approach.
But it hears the carnivore growl, and though Deinocheirus is not the brightest dinosaur, it understands that it is in danger. Instincts kick in, and Deinocheirus looks around for an escape route. But Tarbosaurus is too close, and Deinocheirus has too large a stomach and cannot run, so it must find another way to defend itself.
So, Deinocheirus decides to make itself seem bigger. It lifts its large horse-like head and straightens out its s-curved back, to better emphasize the sail-like structure that lines its vertebrae. The large dinosaur grunts, to show Tarbosaurus it is not afraid.
Tarbosaurus takes a closer look at Deinocheirus, sizing it up. Puffed up, Deinocheirus looks much bigger than Tarbosaurus originally thinks. Eventually, the carnivore decides it is not worth the effort, and backs away.
Deinocheirus waits for the predator to skulk out of sight and then resumes eating. Wanting to spice up its diet, it chooses to dig for its next meal, using its blunt claws to root for food in the ground.
The fish and the plants are not enough for Deinocheirus, and it wants to eat as much as it can before the sun sets and it must settle in for the night.
Facts about Deinocheirus:
- The full name for Deinocheirus is Deinocheirus mirificus, which means “terrible hand”
- Deinocheirus lived in the Cretaceous, about 70 million years ago, in Mogolia’s Gobi Desert
- For 50 years, all scientists knew about Deinocheirus was that it had giant arms
- In 2014, Deinocheirus was finally described in Nature journal, and classified as a primitive ornithomimosaurian (previously scientists thought it was a theropod)
- Deinocheirus has been compared to Jar Jar from Star Wars, because it looks so strange
- Deinocheirus was 35 feet long, weighed 6 tons, had a 3-foot long head, and a narrow body
- The dinosaur also had spines like Spinosaurus, truncated, hoof-like claws on its feet, an ostrich-like neck, flat duck-like bill, large lower jaw, tail feathers, short claws on its hands, bulky, tyrannosaur-like hind legs, and sauropod-like hips
- Deinocheirus ate everything, including plants, fish, and small vertebrates
- Deinocheirus had a small brain size compared to the rest of its body and was too large to run
- Deinocheirus was probably prey for Tarbosaurus, but its enormousness would have helped protect it
Find out more in the I Know Dino podcast, episode 10, “Deinocheirus.”
- “Deinocheirus Exposed: Meet the Body Behind the Terrible Hand” on Phenomena, National Geographic
- “New Fossils Help Reconstruct Bizarre Ostrich-Like Dinosaur” on Sci-News
- “Mystery of dinosaur with giant arms solved” on BBC News
- “Bizzare dinosaur reconstructed after 50 years of wild speculation” on The Guardian
- “Bigger Than A T.Rex, With A Duck’s Bill, Huge Arms And A Hump” on NPR
- “Resolving the long-standing enigmas of a giant ornithomimosaur Deinocheirus mirificus” on Nature
- “Deinocheirus” on Wikipedia