A colossal dinosaur had the biggest claws of all time – making it “Edward Scissorhands on speed.”
They were more than three feet long and were used to attract mates – just like Johnny Depp’s razor-sharp ‘fingers’ helped woo his love interest, Winona Ryder.
The gigantic beast’s terrifying talons were ornaments of display – rather than killing machines, according to new research
Named Therizinosaurus – or the ‘giant claw’ – it lived 75 million years ago and belonged to the theropods – a group of carnivores that included T Rex and Velociraptor.
The creature starred in Jurassic World and the BBC TV show Walking with Dinosaurs.
But the purpose of its unusual hands has remained a mystery – until now.
Study co-author Dr. Chun-Chi Liao, of the Institute of Vertebrate Palaeontology and Palaeoanthropology, Beijing, said: “Therizinosaurus is famous for its sickle-like claws, each as long as a samurai sword: Edward Scissor-hands on speed.
“We all saw Therizinosaurus in ‘Jurassic World’ hitting deer and killing the giant predator Giganotosaurus. However, this is unlikely.
“These long, narrow claws were too weak for combat. Our engineering simulation shows that these claws could not withstand much stress.”
The international team also focused on its much smaller cousin Alvarezsaurus whose rock-pick-like claws have attracted almost as much attention. These were used for digging, it turns out.
(Institute of Vertebrate Palaeontology and Palaeoanthropology via SWNS)
Lead author Zichuan Qin, a PhD student at the University of Bristol, developed computer simulations to identify functions based on detailed comparison with living animals.
Claws were represented in three dimensions from CT scans and modeled for stress and strain using engineering techniques.
Qin’s supervisor Professor Michael Benton said: “Alvarezsaurs and therizinosaurs are definitely the strangest cousins among dinosaurs.
“Alvarezsaurs were the tiniest dinosaurs ever, the size of chickens, with stubby forelimbs and robust single claws, but their closest relative, the therizinosaurs, evolved in the exact opposite path.”
Therizinosaurus reached up to 40 feet long and six tons in weight. It roamed conifer forests on the edges of today’s Mongolian desert.
It ate plants and meat, using its long neck to stretch for leaves growing on tall trees.
Dr Liao said: “Not all therizinosaur hand claws were so useless in combat, but most other related species could use their claws as powerful hooking tools when feeding on leaves from the trees.
“So we conclude the largest claws of any animal ever were actually useless in mechanical function, and so must have evolved under sexual selection to be used in display.
“The adult Therizinosaurus I guess could wave the claws at a competitor and effectively say, ‘look at me, back off’ or wave them around in some way like a peacock can use its tail in display to attract females for mating.”
The Mongolian desert in the Late Cretaceous was home to fearsome predators. Perhaps the most terrifying was Tarbosaurus, an Asian relative of Tyrannosaurus.
Qin said: “Our previous work has shown alvarezsaurs evolved to become the tiniest dinosaurs by the end of the Cretaceous, and these dinosaurian midgets were using their punchy little claws for digging into ant hills and termite mounds. They were ant-eaters.
“The early alvarezsaurs, like Haplocheirus from the Jurassic, had multifunctional hands, but they were not good at digging. Their much smaller descendants had the efficient digging hands so they could feast on the Late Cretaceous termites.”
Therizinosaurus also had weird feet – resting on four toes while standing and walking. Most theropods only had three.
Co-author Prof Emily Rayfield, also of Bristol University, said: “Science and technology cannot bring dinosaurs back to life, but advanced computing and engineering techniques can show us how extinct animals lived.
“Especially for extinct animals like alvarezsaurs and therizinosaurs, they are so bizarre that we even can’t find any living animals like them.
“Luckily, advanced technology can help us to simulate, on a computer, the functioning of extinct animals using fundamental engineering and biomechanical principles.
“This study shows very well how selection for function can lead to the emergence of specific, sometimes very bizarre, forms.”
Produced in association with SWNS Talker
