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With ecosystems as diverse as oceans, plains and frozen tundras, North America is home to giant and ferocious predators. But these modern creatures – including alligators, great white sharks, and polar bears – appear tiny next to the continent’s slew of ancient predators. So what are the biggest predators to ever live in North America?
As for the furry animals, the largest predatory mammal in North America was probably the enormous short-faced bear (we are arctic), said Ross MacPhee, senior curator of mammals at the American Museum of Natural History in New York City. Sometimes affectionately referred to as a “bulldog bear,” this now extinct creature had a short, broad muzzle. According to University of Iowa Museum of Natural History.
It can be difficult for scientists to assess the exact body weight of an extinct species because they have to extrapolate those numbers using existing species as benchmarks, MacPhee told Live Science in an email. However, paleontologists comfortably estimate that the short-faced bear probably weighed around 1,540 pounds (700 kilograms). Modern Polar bears (Ursus maritimus) are not too far away – the largest males stand around 5 feet (1.5 m) at the shoulder and weigh around 1,300 pounds (600 kg), according to Polar Bears International.
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Short-faced bears became extinct about 11,000 years ago, near the end of the last Ice Age. To find a more massive terrestrial predator, we will have to travel further in time. The largest predatory dinosaur in North America is also the most famous on the continent: the king, Tyrannosaurus Rex.
During the end Cretaceous period, about 100 to 66 million years ago, North America was a land of monsters. “Carnivorous dinosaurs had unbelievable variety in North America through the Mesozoic [252 million to 66 million years ago]”Andrew Farke, director of the Raymond M. Alf Museum of Paleontology in Claremont, Calif., Told Live Science in an email. There was the thorny back Acrocanthosaurus, sharp claws Deinonychus, and the thin, feathery Microvenator.
But at nearly 3.5m high at the hips and up to 12.3m long, according to an almost complete specimen of T. rex the size of a school bus known as Stan, the terrible tyrant. rex dominated most of his carnivorous contemporaries. Acrocanthosaurus, a “shark-toothed” cousin of tyrannosaurs and a member of a group known as carcharodontosaurs, nearly matched T. rexin length but was lighter, weighing 6.8 tons (6.1 metric tons), compared to 7.8 tons (7.1 metric tons) for T. rex, according to the American Museum of Natural History. T. rex used all that volume to his advantage: With his powerful jaw muscles, he could deliver up to 6 tons (5.4 metric tons) of pressure per bite – enough to tear steel as if it were of a piece of paper, according to a 2019 study in the journal The Anatomical Record.
The only dinosaurs alive today are birds, making the largest living dinosaur in North America the California condor (Gymnogyps californianus). At 10 feet (3 m) from wing tip to wing tip, this bird is significantly smaller than its former carnivorous cousin T. rex, but formidable in itself, feeding on the carcasses of deer, pigs, cattle, sea lions and even whales, according to the Cornell Lab of Ornithology.
When it comes to ancient marine mastodons, a giant reptile takes the cake. Ichthyosaurs were a group of predatory marine reptiles that lived in the Mesozoic era, around the same time as dinosaurs. At the end of the Triassic period, about 237 million years ago, an ichthyosaur known as the Shonisaurus sikanniensis began swimming in the waters of what is now British Columbia, Canada.
“S. sikanniensis is considered the largest known marine reptile of all time, ”Kenshu Shimada, professor of paleobiology at DePaul University in Chicago, told Live Science. There is a debate about the genus of ichthyosaur S. sikanniensis belonged to: Shastasaurus Where shonisaurus. Members of both genera were large, streamlined, and swift, although the species of the shonisaurus the genus had a barrel-shaped chest and a long snout compared to the thin, shorter snout Shastasaurus, according to University of Portsmouth paleontologist and paleoartist Mark Witton.
Whatever the taxonomy, there is no doubt that S. sikanniensis was absolutely colossal; it measured an astonishing 65 feet (20 m) length from snout to tail, “about three times as easily as the largest known living great white shark,” Shimada said. But size doesn’t always mean ferocity. A 2011 study in the journal PLOS A suggested that S. sikanniensis may have been a suction eater, sucking up soft-bodied prey such as squid and belemnites (shelled squid).
Each of these creatures, however, eventually became extinct as a result of environmental upheaval. Like many highly specialized predators, once their prey became scarce, they simply could not meet their energy needs. “At some point, bigger isn’t better,” MacPhee said.
Originally posted on Live Science.
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