Fossils unearthed during construction of a water pipeline in the Gobi Desert of Mongolia have revealed one of the oddest members of a rather strange group of dinosaurs, a creature whose two-fingered hands sport a pair of menacing curved claws. The dinosaur, named Duonychus tsogtbaatari, measured about 3 meters long, weighed approximately 260 kg and lived roughly 90 to 95 million years ago during the Cretaceous Period, researchers said. Its claws measured about 30 cm long.
Duonychus was a medium-sized member of a group of awkward-looking dinosaurs called therizinosaurs, which were known for having a rotund torso, long neck, small head, bipedal stance, feathers on the body and massive claws on the hands. While they were part of the dinosaur clade called theropods that included all the meat-eaters such as Tyrannosaurus and Spinosaurus, therizinosaurs preferred plants on their menu.
Therizinosaurs, which inhabited Asia and North America, are distinguished by their large claws. Until now, every known therizinosaur had three clawed fingers. But Duonychus possessed one fewer, making it fitting that its name means “two claw.”
Photo: Reuters
“Therizinosaurs are some of the weirdest dinosaurs ever. They were theropods — so, related to meat-eaters — but they looked like giant feathered sloths,” said paleontologist Yoshitsugu Kobayashi of Hokkaido University Museum in Japan, lead author of the research published on Tuesday in the journal iScience.
“Duonychus takes that weirdness even further. It had this short, two-fingered hand with claws like a raptor (swift meat-eating dinosaurs), but it used them to eat plants. It’s like evolution said, ‘Let’s try something totally new.’ And it worked,” Kobayashi said.
The researchers said this Duonychus individual was not fully grown. It roamed a semi-arid environment with river channels alongside other therizinosaurs, armored dinosaurs, horned dinosaurs, duck-billed dinosaurs and a smaller forerunner of Tyrannosaurus called Alectrosaurus.
Photo: Reuters
While the skeleton recovered was incomplete — for instance, missing its skull and legs — the arms and hands were well-preserved.
One of the claws retained its outer covering — a sheath of keratin, the same material as in our fingernails — rather than just the underlying bone. The keratin sheath added more than 40 percent to the claw’s length.
“These were big, sharp and nasty claws,” said paleontologist and study co-author Darla Zelenitsky of the University of Calgary in Canada.
“That’s incredibly rare,” Kobayashi said of the keratin fossilization, “and it gives us an extraordinary window into how these dinosaurs actually used their hands in life. The hands are beautifully preserved and show a ton of detail, including fused wrist bones, stiff joints and the two massive claws.”
The claws may have served multiple functions, though primarily used for grabbing and pulling down branches to feed on leaves.
“They could have used the claws for other purposes as well, perhaps for grappling, defense, digging and maybe even recognizing one’s own species — ‘Hey, look at me. I also have only two fingers,’” Zelenitsky said.
Duonychus is an example of digit reduction — losing fingers or toes through evolution. The first land vertebrates had eight digits. The earliest dinosaurs had hands with five fingers, just as people do, but many dinosaur lineages experienced digit reduction over time.
The discovery of Duonychus means there are now no fewer than five lineages of theropods known to have independently evolved just two fingers on each hand. The most famous of these was T. rex, a member of the group called tyrannosaurs whose puny arms were way out of proportion with its enormous head and torso.
So why would fewer fingers be beneficial?
“With dinosaurs that grasped vegetation during foraging, one would think more fingers would be better. That was obviously not the case with Duonychus, as its hand construction with two fingers seemed to suit it just fine. I suspect it may have had a specialized feeding behavior or food source,” Zelenitsky said.
“Tyrannosaurs were hypercarnivorous beasts with massive skulls and jaws designed for seizing and killing prey,” Zelenitsky added. “For them, the fingers and arms were probably reduced because they were pretty useless compared to their skull.”
Three big changes have transformed the landscape of Taiwan’s local patronage factions: Increasing Democratic Progressive Party (DPP) involvement, rising new factions and the Chinese Nationalist Party’s (KMT) significantly weakened control. GREEN FACTIONS It is said that “south of the Zhuoshui River (濁水溪), there is no blue-green divide,” meaning that from Yunlin County south there is no difference between KMT and DPP politicians. This is not always true, but there is more than a grain of truth to it. Traditionally, DPP factions are viewed as national entities, with their primary function to secure plum positions in the party and government. This is not unusual
More than 75 years after the publication of Nineteen Eighty-Four, the Orwellian phrase “Big Brother is watching you” has become so familiar to most of the Taiwanese public that even those who haven’t read the novel recognize it. That phrase has now been given a new look by amateur translator Tsiu Ing-sing (周盈成), who recently completed the first full Taiwanese translation of George Orwell’s dystopian classic. Tsiu — who completed the nearly 160,000-word project in his spare time over four years — said his goal was to “prove it possible” that foreign literature could be rendered in Taiwanese. The translation is part of
The other day, a friend decided to playfully name our individual roles within the group: planner, emotional support, and so on. I was the fault-finder — or, as she put it, “the grumpy teenager” — who points out problems, but doesn’t suggest alternatives. She was only kidding around, but she struck at an insecurity I have: that I’m unacceptably, intolerably negative. My first instinct is to stress-test ideas for potential flaws. This critical tendency serves me well professionally, and feels true to who I am. If I don’t enjoy a film, for example, I don’t swallow my opinion. But I sometimes worry
Mongolian influencer Anudari Daarya looks effortlessly glamorous and carefree in her social media posts — but the classically trained pianist’s road to acceptance as a transgender artist has been anything but easy. She is one of a growing number of Mongolian LGBTQ youth challenging stereotypes and fighting for acceptance through media representation in the socially conservative country. LGBTQ Mongolians often hide their identities from their employers and colleagues for fear of discrimination, with a survey by the non-profit LGBT Centre Mongolia showing that only 20 percent of people felt comfortable coming out at work. Daarya, 25, said she has faced discrimination since she
RSS