00:00Well, it seems we got dinosaurs completely wrong.
00:05Plus, the movie's created an image of them that's hard to get out of the head now.
00:10You know what I'm talking about?
00:12Dinosaurs as giant lizards.
00:15I mean, lizards are cool.
00:17There's a type of lizard found in the streams of Costa Rica
00:19that can stay under the water for up to 16 minutes.
00:24They create a pocket of air at the top of their snout
00:27and breathe exhaled air while submerged.
00:31So-called horned lizards can spout blood out of their eyes,
00:34shooting it up to six feet.
00:36Poor lizard has to do it when it gets closer to the mouth of its attacker,
00:40since this bad taste makes a predator change their mind
00:43and go after some more delicious bites.
00:47Then there's the basculist lizard that can run over water
00:50while making its escape from bigger animals in the rainforest of Central America.
00:55They can do that for short distances.
00:57But still, it gets to rear up and rely on flaps of skin
01:01on the toes of its hind legs to have more surface area.
01:05Many types of lizards have had to develop such unusual adaptations.
01:10So they didn't become an easy, quick snack
01:12for snakes, coyotes, hawks, foxes, and other big animals going after them.
01:18They wouldn't have to do it if they had some giant cousins that would protect them.
01:23Like dinosaurs.
01:24But even though they look like gigantic scary lizards in the movies,
01:29it's not what you would see if you had the chance to go back to the dino age.
01:34You'd have to be aware and run if you saw feathery creatures instead.
01:39Feathers don't sound that scary because birds are the only animals alive today that have them.
01:44But millions of years ago, it was a different story.
01:48Some of the most fearsome dinosaurs were covered in feathers, too.
01:52Of different shapes, sizes, and colors.
01:55For example, check this fella, a cousin of the famous T-Rex.
02:00It was a scary predator that weighed one and a half tons
02:03and was covered in a shaggy coat of filaments known as protofeathers.
02:07These feathers were not used for flying, but to stay warm or attract mates.
02:14Or take a velociraptor, for example.
02:17For so long, we've believed it's a sleek predator with the skin of a lizard.
02:22But it turns out it was a much smaller, colorful creature covered in feathers,
02:26like some sort of bird.
02:28Many of their dino relatives had pretty long feathers all over their forearms,
02:33together with downy feathers that were spread across the rest of the body.
02:36This works for most of the meat-eating dinosaurs, or so-called theropods.
02:42There were tiny ones with a tail fan full of feathers,
02:46or those with shiny feathers in a mix of colors.
02:50It was similar to a hummingbird.
02:53Maybe it wouldn't be that scary to face dinosaurs after all.
02:56Some of the fossils researchers found are well-preserved.
03:00In combination with modern techniques they used to study these fascinating creatures,
03:04they found out dinosaurs came in different colors.
03:09Archaeologists found some fossilized feathers together with fossils of melanosome structures.
03:14Those are pigments that gave them gray, brown, and black colors,
03:18like Ancyornis, whose body was almost entirely black.
03:22It's reminiscent of a bird with wings and fluffy tail feathers on his hind legs,
03:27together with a pretty long tail that could fan out.
03:30This fella had white stripes along its wings, too.
03:34It also had a brown head crest.
03:36This one was perhaps there as a display or used to communicate with other Ancyornis dinosaurs.
03:43And check out this one.
03:46It also had a bristly tail and different markings on its body.
03:50Thanks to the fossils they found,
03:52researchers have been able to reconstruct the appearance of this dinosaur,
03:56giving it so many details.
03:58Not only did dinos look like birds, but they also behaved similarly to them.
04:05For example, they sat on their nests to protect their eggs
04:08and most likely used their feathers for displays.
04:12There was a discovery in Canada that revealed one type of dinosaur
04:16had a fleshy crest on its head, like a rooster's comb.
04:20Scientists think this crest was likely used as a way to attract a mate
04:24or show off to other dinosaurs.
04:26Then, there's the scariest of them all in the dinosaur kingdom, the T-Rex.
04:33Can you imagine this one in a birdie version?
04:37Also, you may have seen pictures of T-Rex with its big sharp teeth
04:41and its jaws wide open, kind of always ready to bite into its prey.
04:46But these images might be completely wrong.
04:49Some recent research tells us these top predators might have had something that we take for granted
04:55in almost all land animals today.
04:58Lips.
05:00Now, think about it.
05:01When you look at a crocodile or an alligator, you don't see any lips covering their teeth.
05:07So, everyone has always assumed that their prehistoric relatives,
05:11theropod dinosaurs, were the same way.
05:14Well, not quite.
05:16Researchers looked at fossilized dinosaur skulls and compared them to modern reptiles
05:22and found out these dinosaurs likely had soft tissue around their mouths that functioned like lips.
05:29Scientists learned this while studying small passageways in the upper jaws of dinosaur skulls,
05:35something called foramina.
05:38Foramina allows blood vessels and nerves to reach the soft tissues around the mouth.
05:43In lipped reptiles, like lizards, these foramina are arranged in a line along the edge of the jaw near the teeth.
05:50Scientists examined the enamel of the teeth, too.
05:53When enamel dries out, it wears down more easily.
05:57The researchers found that the side of alligator teeth that is continuously exposed
06:02erodes more like the wetter side facing the inside of the mouth.
06:06However, in theropods like T. rex, the teeth have an even wear pattern.
06:11This tells us teeth were kept covered and moist.
06:16Based on this, scientists believe theropods with long, sharp teeth, like T. rex,
06:22could also close their mouths with their teeth inside.
06:25The teeth of theropods in monitor lizards are similar in size,
06:29and monitor lizards can close their mouths completely.
06:33Therefore, it's likely that theropods also had lips that allowed them to fully close their mouths.
06:39However, it's not known if they wore lipstick.
06:45Interestingly, the study also revealed a neat row of jaw foramina
06:50in a pretty cool extinct early cousin of crocodilians.
06:53Also, lips may have been present in the earliest archaeosaurs,
06:58a group of reptiles that gave rise to dinosaurs and crocodilians.
07:03Now, this might not seem like a big deal,
07:05but it truly changes how we think about how these dinosaurs ate.
07:10If they had lips, it's possible that they could have controlled their bites more precisely,
07:16and maybe even chewed their food instead of just tearing it apart.
07:19Some still believe differently, saying T. rex and other theropods
07:25had flat scales like crocodiles, all the way down to the edges of their jaws.
07:30So, I guess the mystery of dinosaur lips continues.
07:35Now, you might be wondering,
07:36did sauropod dinosaurs like the titanosaur have feathers too?
07:42Some scientists believe all dinosaurs, including sauropods, had feathers.
07:46Just as you can see, all mammals have at least some hair.
07:52But big mammals, like elephants, have limited hair.
07:55So, it's possible that sauropods didn't have many feathers.
07:59Since feathers are something you'll stumble upon in a fossilized shape,
08:03the chances of finding those of sauropods,
08:06or similar dinosaurs, are definitely lower.
08:10Plus, there's a chance big dinosaurs that lived in warm weather
08:13didn't have feathers at all.
08:14Many of these feathered dinosaur fossils have been found in China.
08:21These fossils have helped us understand
08:23the transition from feathered dinosaurs to birds.
08:27Because birds could be the only animals that survived
08:30and are around today that are directly related to dinosaurs.
08:34Ooh, I wonder what happened here.
08:37It could be that some kinds of theropods
08:39started hiding in trees more
08:41while searching for food and protection.
08:43So, their bodies evolved to become even smaller
08:47to survive harsh conditions
08:48and dangerous predators lurking after them.
08:52But still, it's a transition
08:54from the most incredible predator the animal kingdom has seen
08:58to squawking chickens.
09:00Talk about how evolution mostly moves animals forward.
09:04Hey, stop it!
09:05I didn't mean it.
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