News From Space: Ancient Meteorite Crater Found

meteorIn southern Alberta, scientists have found a vast, ancient crater that they claim dates back some 50 to 70 million years. Discovered entirely by accident in near the hamlet of Bow City, some 20 km south-west of Brooks, and 100 km south-east of Calgary. According to assessments of the impact zone, researchers estimate that the space rock would have been the size of an apartment block, and would have left a crater 8 kilometers wide and roughly 2 and half km deep.

All told, this explosive force of this impact would have been 200 times stronger than the most powerful thermonuclear bomb ever built. That’s basically a force of 1000 megatons, a detonation so powerful that anything within 200 km of the impact would have received 1st-degree burns. To put that in perspective, this means that the city of Calgary would have been decimated by the blast, and in Edmonton, some 400 km away, every window would shattered.

alta-meteorite-crater-20140507But even more awe inspiring was the long-term effects of the damage, which would have thrown enough dust and debris into the atmosphere to mess with the Earth’s climate for the next few years. As Schmitt put it:

Something of that size, throwing that much debris in the air, potentially would have global consequences; there could have been ramifications for decades.

But after eons of erosion, very little of the crater is left. In fact, the discovery happened entirely by accident when a geologist – who was doing some routine mapping of the underground layers a few meters beneath the surface – apparently noticed a circular disturbance that was covered. Schmitt and his lab were called in to inspecting the feature and used seismic data to create a complete image of it. They quickly realized that it was most likely an impact crater, complete with a central peak where the meteorite would have struck.

Alberta_craterThe size of the object can only be estimated, but assuming the meteor was composed mostly of iron, it would have had to have been between 300 and 500 meters in diameter to create a crater of this size. If the meteorite was rock, it would have had to have been a kilometre across. Schmitt said the crater is a rare opportunity to study the floor of an impact crater. His team is now looking for certain types of minerals that form only under certain conditions so as to confirm the crater is from a meteor impact.

But he doesn’t have much doubt. As he put in a recent interview with CBC news:

We’re able to get at the lower parts of (a crater) and see how rocks have been moved around… We’re pretty confident it can only be a meteorite impact. It’s pretty clear.

Once they’ve had a chance to uncover and examine the area in greater detail, a clear picture of the meteorite’s size, composition, and what lasting marks its impact left beyond the crater. This information will only contribute to our understanding of our Solar System, but of the history of our planet as well.


Paleonews: Reconstructing what Dinosaurs Looked Like

dinosaur_bonesSince the first discovery of their remains was made, modern humans have struggled to reconstruct how dinosaurs lived, behaved, and even appeared. As simple as it may seem to the rest of us, paleontologists understand that bones alone do not an accurate representation make. And over the years, many theories have been advanced as to what the full, fleshy forms of dinosaurs truly looked like.

And thanks to a find made in Grand Prairie, Alberta last year, one of the richest source of dinosaur bones in the world, scientists are that much closer to getting an accurate picture as to what one candidate – Edmontosaurus regalis – looked like. In short, the find revealed a body part never seen before on any dinosaur –  a soft, fleshy comb on its head, similar to those found on roosters.

edmontosaurus-regalisAccording to Victoria Arbour, a University of Alberta paleontologist who co-authored the scientific paper published Thursday in the journal Current Biology, the comb constituted a “structure that was completely unexpected.” And that it “kind of makes us wonder what other dinosaurs might have had.” The find is also interesting because of the connection it draws to the biology of today’s animals, something which is still considered distinct from prehistoric creatures.

Edmontosaurus are a duck-billed, plant-eating dinosaur that grew to be 12 metres long and was thought to have roamed North America in herds during the late Cretaceous, about 75 and 65 million years ago. It also belonged to a group of dinosaurs known as hadrosaurs, a family of duck-billed herbivores which were the most common dinosaurs on the continent at the time.

edmontosaurusPhil Bell, a paleontologist at the University of New England in Armidale, Australia, was with the Philip J. Currie Dinosaur Museum currently under construction in Grand Prairie, Alta., when he uncovered the fossil last summer with geologist Federico Fanti of the University of Bologna. As the lead author of the paper, Bell claims that the new findings are a major breakthrough in determining the dinosaur’s behavior.

In particular, the existence of the comb adds to evidence that Edmontosaurus was a social animal, as ornaments like combs and crests are typically used for communication among animals such as roosters, especially in relation to competition for females:

[E]quivalent to discovering for the first time that elephants had trunks. These findings dramatically alter our perception of the appearance and behaviour of this well-known dinosaur. We might imagine a pair of  male Edmontosaurus sizing each other up, bellowing, and showing off their head gear to see who was the dominant male and who is in charge of the herd.

dinosaur_fossilsAnd of course, this find demonstrates many of the limitations imposed on paleontologist, as fossils typically only preserve the bones of an animal and not fleshy structures. But in rare cases, fossils are found that are described as “mummified”, where bones are in the same positions relative to each other that they would have been in life, with impressions of the skin preserved on top.

According to Arbour, it’s not clear what conditions lead the preservation of skin impressions, but it likely involves the animals dying in a flood and being quickly buried by sand or mud. She added that even when skin impressions are preserved, they are often only visible in certain lighting or when the rock breaks a certain way, which may be why combs hadn’t been noticed on earlier “mummified” Edmontosaurus fossils.

dinosaur_skinimpressionsWhile earlier hadrosaurs had bony crests, researchers thought the crest had been completely lost in Edmontosaurus. The new discovery suggests that, in fact, the dinosaurs’ crests had changed, but remained an important feature. Bell said it also suggests that similar structures may have been missed in other dinosaurs:

There’s no reason that other strange fleshy structures couldn’t have been present on a whole range of other dinosaurs, including T. rex or Triceratops.

So really, this single find could have far-reaching implications for the field of paleontology. And with time, more discoveries, and additional refinements to the excavation process, we might just get a full and complete picture of what life really and truly looked like on Earth millions of years ago.