It’s a classic movie scene. Two children in a car huddle in terror. The ground shakes with the approach of something scary. We catch glimpses of the beast: a passing tail, an enormous clawed foot and a beady eye looking through the car’s rain-streaked window. As the tension builds, the camera finally pulls back as the dinosaur roars triumphantly, and the audience cheers as the world’s favourite dinosaur is finally revealed: Giganotosaurus!
If you’re a little confused, don’t worry. That’s not how Jurassic Park’s most famous scene plays out. The star of that scene is—of course—Tyrannosaurus rex. But at the same time that Steven Spielberg was planning his movie over 30 years ago, palaeontologists in Patagonia were making some extraordinary discoveries that could have rewritten his script. We look at why these newly revealed dinosaurs deserve their place in the sun (and cinema screen).
Dinosaur city
The Patagonian coastline in Argentina’s Chubut province has long been known for big animals. Wildlife watchers know the area around Peninsula Valdes as one of the best places in the world to see southern right whales. But when you fly into the nearby city of Trelew you’re met with a rather different creature on the road from the airport: a life-sized statue of Patagotitan, the largest dinosaur in the world.
Think of the classic Diplodocus shape and you’re got a rough image of Patagotitan. These are the sauropod dinosaurs, with massive bodies on tree trunk legs, long necks ending in the tiniest of heads and immense whip-like tails Everyone knows that Diplodocus was a big animal, but it was dwarfed by Patagotitan. An adult measured 37 metres from head to tail, and clocked in at around 57 tonnes in weight, making it about a dozen metres longer than Diplodocus, and four times as heavy. Trelew’s Museo Egidio Feruglio, which is one of Argentina’s best paleontological museums, has a specimen on display, and the femur alone is over two metres long.
Patagotitan is a relative newcomer to the dinosaur scene. It was discovered in 2012 not far from Trelew, in one of the most exciting palaeontological finds of recent decades, with more than 150 fossils from the remains of at least six specimens in the same site. But Patagotitan is only one of a remarkable series of fossil discoveries in this part of Patagonia.
Titanosaurs and more
Patagonia’s run of astonishing dinosaur discoveries began back in 1987 in Neuquén, nearly 500 miles (800 km) to the northwest. Palaeontologists here uncovered another massive sauropod, which was christened Argentinosaurus. While it’s a tricky business reconstructing the size and mass of dinosaurs from a handful of bones, it was immediately clear that Argentinosaurus was one of the largest land animals that ever lived, possibly reaching somewhere between 30-35 metres in length. Even the name of the dinosaur family it belonged to gives no cause for confusion: titanosaurs.
More relatives of Argeninosaurus followed in quick succession: Tehuelchesaurus (named for the Tehuelche people who first lived in this part of Patagonia), Futalognkosaurus and eventually Patagotitan. Two legged dinosaurs followed, and in 1993 the partial skull and remains were uncovered of a tyrannosaurus, named Gigantosaurus. Like the titanosaurs, this carnivorous dinosaur was a massive beast, likely measuring around 13 metres in length. This easily makes it the equal of its famous northern cousin T. rex, even if it has yet to earn the place on the cinema screens it surely deserves.
But why has Patagonia become such a hotspot for dinosaurs? And how did they get so big?
Why Patagonia?
The golden age of palaentology took place in the late 19th and early 20th Century, when much of Patagonia was yet to be explored. Fossil hunters followed the US Army into the newly conquered lands of the American West, and it was here that they discovered some of the best-known dinosaurs, including Brontosaurus, Triceratops and Tyrannosaurus rex. It has only been in recent decades that attention has turned to the other end of the Americas
What made the Badlands of Montana and Wyoming so great for fossils is exactly what makes this part of Patagonia today’s dinosaur hotspot: open, sparsely vegetated landscapes with plenty of exposed rocks being slowly eroded by the elements. Many of Patagonia’s dinosaurs, including Patagotitan and Argentinosaurus, were found by people literally stumbling upon them, then calling in the experts.
Patagonia’s geological history also helps explain why this became the land of the titanosaurs. Around 100 million years ago, the ancient supercontinent of Pangaea started to break up and South America became cut off from the rest of the world, allowing its dinosaurs to evolve in isolation. Sauropods here flourished, while their relatives in North American became extinct. Alongside them, big Patagonian carnivores thrived. No Tyrannosaurus rex ever saw a brontosaurus, but in Patagonia, the enormous Gigantosaurus may well have scavenged on dead Patagotitans or tried to hunt their young, who were more than big enough for a very good meal.
Why so big?
You can get a taste of what the region’s prehistoric landscape might have looked like in the northwestern corner of Argentinian Patagonia, where massive araucaria trees (better known as monkey puzzle trees) still flourish in places like Lanín National Park. Giants like Argentinosaurus and Patagotitan grazed like giraffes from their tree tops, and then took up to a week to digest their meals.
Their long necks allowed them to forage widely for food without having to move too much – a crucial energy-saving feeding method for big animals. Like elephants, titanosaurs used their trunks to feed and had straight, pillar-like legs and large padded feet to support their weight.
However, titanosaurs had some pretty nifty biological innovations that allowed them to reach sizes that even the most ambitious elephant could never dream of. Their pillar-like legs could support great weights efficiently, while their wide hips allowed them to devote resources to enormous stomachs. But their real secret was in their bones, which were hollow and light, much like modern birds. Also like birds, their bones contained air sacs that allowed them to continuously absorb oxygen in a far more efficient manner than any mammal. This meant they used less energy to move around, and produced less body heat when they did. When put together, all these adaptations meant that the titanosaurs had been engineered by evolution to allow them to reach their gigantic potential.
New frontiers
In recent years, Argentinian and international palaeontologists have been adding enormously to the picture of prehistoric Patagonia. New discoveries are being made each year, and an ever more detailed picture is being revealed about these ancient giants and the world they lived in. With each new fossil unearthed, Patagonia cements its place as the true Jurassic Park.
For now, Trelew’s enormous Patagotitan statue stands patiently looking out over the steppe, waiting for popular culture to catch up. For everyone who passes, it’s a towering reminder that Patagonia is one of the most exciting destinations in the world for dinosaur hunters and dinosaur lovers alike continues to grow. It’s time for Hollywood to make that call.
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