Last issue, I delved into the history of mass extinctions. This time I’m going to talk specifically about the K/T event (Cretaceous-Tertiary extinction), with emphasis on some of the creatures that it took with it. The K/T event happened around 66 million years ago and is the major extinction event that most people know about, catalyzed by the meteor impact on the Yucatan Peninsula in Mexico, causing the majority of life on Earth to go extinct. For a long time, paleontologists thought that life in different sections of the world would have been affected differently, but recent evidence from Antarctica disproves this. Over a six year long study conducted by the University of Leeds and the British Antarctic Survey, researchers were able to identify over 6,000 fossils which mark a dramatic series of extinctions concluding 66 million years ago.
Most of the popular dinosaurs, the likes of which are seen in Jurassic Park, come from areas which today are dry and arid, like the badlands in North Dakota and Alberta. But Antarctica also housed some pretty amazing creatures in its time. During the age of the dinosaurs, Antarctica was still a very southern continent, but the global climate was much warmer. The frozen plains of the modern South Pole probably resembled Brazil more than the frozen expanses seen today. Here are some of my favourites from the Antarctic creatures of the dinosaur age.
The first carnivorous dinosaur to be found in Antarctica was the Cryolophosaurus Ellioti, whose name comes from the Latin for cold, crest and lizard. Cold, though true today, is largely a misnomer. During the Early Jurassic period, the time when the Cryolophosaurus lived, Antarctica was actually close to the equator. This creature was a theropod, the same family as the Allosaurus or Tyrannosaurus, and closely resembled its more well known cousins. Large for its time, the Cryolophosaurus measured only around twenty feet long, on average eight feet smaller than the Allosaurus. Eight feet might not seem like a huge difference, but the extra size meant that the Allosaurus could take on larger, more dangerous prey than its ancestor. The Cryolophosaurus’ defining trait was the crest that sat above its head, likely used simply to attract a mate.
A counter to the Cryolophosaurus is the Glacialisaurus Hammeri, a herbivore that also lived during the Early Jurassic and may have been the prey of the Cryolophosaurus. The Glacialisaurus is one of the smaller sauropods that has been discovered, weighing an estimated 5 tons. Compared to its larger cousins the Brachiosaurus (39 tons) and Brontosaurus (17 tons), the Glacialisaurus would have been positively cute. As an earlier breed than its larger family, the Glacialisaurus may have even stood on its hind legs to reach the leaf canopy it ate from. As natural selection worked on the Glacialisaurus, the larger of the species thrived and evolved into the larger sauropods I mentioned earlier.
The last dino I want to discuss is the Antarctopelta Oliveroi, an ankylosaurid from the late Cretaceous. The Ankylosaurus is one of my favourite dinosaurs, and is fairly underrated (maybe because its name is harder for children to pronounce). As armoured herbivores that likely traveled in herds for protection, they may have been a natural enemy of the Tyrannosaurus. The Antarctopelta may even have had spikes protruding from its front shoulders, giving it a very menacing look.
The Antarctic peninsulas likely house many, many more fossils, but because of the harsh conditions, excavating them is difficult and dangerous work. It took a team of paleontologists over a decade to excavate a single Antrarctopelta Oliveroi skeleton. Storms have been known to degrade and sometimes destroy partially exposed fossils during digs as well. Due to Antarctica’s location during the age of the dinosaurs, in particularly in the Triassic and Jurassic Eras, it may house many fossils that help us learn more about the evolution of dinosaurs. For example, the first two dinosaurs I discussed today help tell the tale of the early sauropods and therapods. Let us hope we can keep studying and uncovering new species!
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