Hey there, I'm Mike, welcome to the salon, this is mental_floss video and did you know that Walt Disney insisted on an anatomically incorrect tyrannosaurus rex in the film Fantasia?  He knew that the dinosaur only had two fingers on each hand but added an extra finger per hand because he thought it looked better and scarier and I think he was right, and that is the first of many facts about non-Avian dinosaurs that I'm gonna share with you today.

(Intro)

Alright, so let's start with some dinosaur basics.  They probably emerged around 230 million years ago, which was the Mezozoic Era.  

They then died out 65 million years ago, which means that they were around for about 165 million years total.  To put that in perspective, modern humans have only existed for like, 200,000 years.  So 165 million years is enough time for a ton of different dinosaur species.

We don't know exactly why they went extinct, but it was probably a long process.  Experts believe that dinos were already dying out when an asteroid hit the Earth which moved their extinction along.  Just a helpful extinction nudge.

According to one study, 41% of adults in the US think that humans and dinosaurs coexisted.   They're right, but for the wrong reasons.  We live alongside birds, which are technically dinosaurs, but we never lived alongside non-avian dinosaurs.

Humans first discovered dinosaur bones in the 1820s and now we know of over 700 different species of dinosaur, thanks to the many dino discoveries since then.

If you think you know all there is to know about dinosaurs because you've seen Jurassic Park, think again.  The movie actually got some dinosaur facts totally wrong.  Like velociraptors were definitely not as large as they appear in the films.  In reality, they were probably about 20 inches tall.  Adorable.

In both the film and the book, a dilophosaurus shoots venom, causing blindness and paralysis.  This was completely made up for dramatic effect.  Experts don't believe that the dilophosaurus was venomous at all.

The film also shows a brachiosaurus standing on its hind legs.  According to expert Dr. Heinrich Mallison, the animal "was probably unlikely to use a bipedal posture regularly and for an extended period of time," and if you are interested in more misconceptions about dinosaurs, you can check out our episode on that right here, moving on.

Dinosaurs get classified as either bird-hipped or lizard-hipped.  This has to do with the pubis bone which points toward the tail in bird-hipped dinosaurs and the other way in lizard-hipped ones, but weirdly, birds descended from lizard-hipped dinosaurs, so technically, birds don't have bird hips.

It took some dinosaurs decades to become full grown.  Like, an allosaurus may have grown for thirty years, but experts believe that many dinosaurs were able to reproduce by the age of eight.  

We still don't know if the T-Rex was a major predator.  Some scientists believe that they were scavengers or at least scavenged in addition to hunting. 

But don't be too disappointed, the T-Rex wasn't that big anyway.  At least, not compared to the dreadnoughtus which was probably around 30-40 tons.  A T-Rex was more like 7-9 tons.  Also adorable.

There's a kronosaurus on display at the Harvard Museum of Natural History that might contain an error.  Some believe that the people who assembled it added too many vertebrae to the animal so that it's larger than a real kronosaurus would be.  Also harder to frighten, because it has more backbone.

And that was a trick fact because as dinosaur fans are already commenting on this video, the kronosaurus wasn't technically a dinosaur.  It was a pliosauroidea, which were marine reptiles that lived during the Jurassic and Cretaceous periods.  Still, pretty cool, rad, fun to talk about.

It is an often-repeated fact that Stegosauruses had brains the size of walnuts.  It's such a popular notion that in 2013, paleontologist Lawrence Whitmer published a paper in which he jokingly proposed that walnut become the standard unit of measurement for dinosaur brain size.

And speaking of stegosauruses, their name means 'roofed lizard', because when they were first discovered, paleontologists believed that the plates on their backs were flat, making them look like they had grooves, but we now believe that the plates stood upright, unlike the brachiosaurus and to me on Saturdays.

Moving on to another famous dinosaur, the triceratops.  There's a region in the Northern US known as Hell Creek Formation and a whopping 50 triceratops skulls have been found there so far. 

It's believed that sauropod dinosaurs used to swallow small rocks to help with their digestion.  Some animals still do this, including crocodiles and birds, which I guess means that eating like a bird at the very least means eating small rocks.

And thanks to dinosaurs, there were feathers before they were used for flight.  Experts think that feathers evolved on dinosaurs before they aided in flying.  They were probably just for display.  

The majority of dinosaur eggs were white, but scientists have found pigments in some fossilized eggshells revealing that they were a blue-green color.

In the 1990s, a fossilized baby dinosaur was found with its guts and windpipe fairly well-preserved.  It was also the discovery of a new species: scipionyx samniticus and it was 113 million years old.

The fossil of only one dinosaur has ever been found in the state of Arkansas and it was named the Arkansaurus.

Another dinosaur starting with the letter 'A', the ankylosaurus, had a huge club tail which may have been used to attract mates or possibly fight.  Or why not both?

In 2014, 120 million year old fossil was found that contained many baby dinosaurs in addition to one older one.  Experts think that the older dinosaur was too young to be the parent of the babies so it could have been a babysitting dinosaur, which wouldn't be too outlandish because some birds use other birds as babysitters, too.  

Google has its own dinosaur, of course, a huge T-Rex replica named Stan that sits outside the company's headquarters.  Well, guess what, Google?  We have our own T-Rex, too.

There's a man named Ray Stanford who has an amazing ability to sense dinosaur tracks.  He lives in Maryland and has found 300 tracks which have been published about in scientific journals.  Stanford also has three tons of rocks containing dinosaur tracks.

And speaking of dinosaur experts, paleontologist Jack Horner has claimed that modern dinosaurs could be made if we get the right DNA from chickens, which are said to be descendents of dinosaurs.  He calls his proposed end result the chickenosaurus.

Finally, I return to the salon, but did I ever really leave, to tell you that there are seven states in the US with an official state dinosaur.  Four additional states have official state fossil that happen to be dinosaurs.  

Thanks for watching mental_floss video which is made with the help of all of these very nice people.  Once again, my name is Mike Rugnetta.  If you like my face, you can see more of it on my YouTube show Idea Channel, and if you like my voice, you can hear more of it on my podcast, Reasonably Sound and let me know your favorite dinosaur in the comments.  I think mine is truckasaurus.