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10 Predatory Facts About Albertosaurus

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Neil Conway

This week, we’re shining our spotlight on the imposing Albertosaurus, one of T. rex’s best-known cousins.  

1. It Was one of Several North American Tyrannosaurs.

Millions of years before Tyrannosaurus rex showed up, smaller relatives like Alaska’s Nanuqsaurus, New Mexico’s Bistahieversor, and Utah’s Teratophoneus—whose excellent name means “monstrous murderer”—terrorized the continent.

2. Some Speculate that Albertosaurus Traveled in Packs.

Ryan Somma

It’s flat-out impossible to fully ascertain an extinct animal’s social norms on the basis of nothing but fossilized bones. With that being said, Albertosaurus skeletons have been found in large groups, prompting a few paleontologists to wonder if these 30-foot carnivores were potential pack-hunters.  

3. Albertosaurus Bit Each Other’s Faces

Ryan Somma

Deep, tell-tale scars reveal that Albertosaurus and Tyrannosaurus would not only bite other members of their own species, but occasionally target a very specific region while doing so: namely, the facial area. One especially-unlucky Albertosaurus managed to survive after having a rival chomp down on its lower jaw twice! 

4. Albertosaurus’ Ancestors Migrated From Asia

Wikimedia Commons

The earliest tyrannosauroids—which evolved in or near modern-day China during the Jurassic period (199.6-145.5 million years ago)—were hardly intimidating. Feathery Dilong paradoxus, for example, would’ve been slightly over 6 feet long when fully grown. Yet, as this formerly-humble group gradually spread out across Asia, Europe, and the Americas, it produced some of the biggest predators our planet’s ever seen.

5. It Wasn’t the Only Dino Named After Alberta.

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Albertaceratops (pictured above) and Albertonykus were also named for this dinosaur-rich Canadian province.

6. Albertosaurus’ Teeth Took a Beating.

Robert Taylor

Ripping through flesh can put a lot of pressure on your pearly whites. Dino tooth expert William Abler has hypothesized that, while feeding, a line of serrations on Albertosaurus teeth helped keep them from cracking.

7. We’ve Got Skin Impressions from Albertosaurus’ Closest Relative.

Wikimedia Commons

Pebbly, Gila monster-like scale impressions have been found in association with Gorosaurus libratus, a sleek carnivore from Montana and Western Canada that is so Albertosaurus-like that some scientists think it really belongs to the same genus. 

8. Compared to T. rex, Albertosaurus Was Almost Petite.

Wikimedia Commons

Though Tyrannosaurus rex only stretched 10 to 12 feet longer than Albertosaurus, most estimates indicate that the bigger dino was significantly heavier. Adult “rexes” are generally thought to have weighed in at 5 to 7 tons. Slender Albertosaurus, on the other hand, likely maxed out at 2 to 3.

9. Juveniles Were Seemingly Built for Speed.

Falashad

Leggy young Albertosaurus had proportionately lengthier hind limbs than mature specimens, indicating that they could’ve far out-paced older rivals [PDF].

10. A Long-Lost Albertosaurus Bone Bed was Rediscovered 86 Years Later.

James West

Finding several large, predatory dinosaurs at the same site qualifies as a major-league discovery. So when fossil-hunting rock star Barnum Brown plucked nine Albertosaurus skeletons from a mass graveyard in 1910, it was a pretty big deal. But the explorer never recorded his treasure trove’s whereabouts for posterity’s sake. For 86 years, scientists could only imagine what other wonders it might yet yield.

But four photographs did survive, and in 1996, paleontologist Phil Currie used these snapshots to finally relocate Brown’s mysterious site. And the good news didn’t stop there: The bones of as many as 26 individual Albertosaurus were found lying in wait.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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May 23, 2017
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