00:00Well, it seems we got dinosaurs completely wrong.
00:04Plus, the movies created an image of them that's hard to get out of the head now.
00:10You know what I'm talking about?
00:13Dinosaurs as giant lizards.
00:15I mean, lizards are cool.
00:17There's a type of lizard found in the streams of Costa Rica that can stay under the water
00:21for up to 16 minutes.
00:24They create a pocket of air at the top of their snout and breathe exhaled air while
00:29submerged.
00:31So-called horned lizards can spout blood out of their eyes, shooting it up to 6 feet.
00:36Poor lizard has to do it when it gets closer to the mouth of its attacker, since this bad
00:41taste makes a predator change their mind and go after some more delicious bites.
00:47Then there's the basculus lizard that can run over water while making its escape from
00:52bigger animals in the rainforests of Central America.
00:55They can do that for short distances, but still, it gets to rear up and rely on flaps
01:00of skin on the toes of its hind legs to have more surface area.
01:06Many types of lizards have had to develop such unusual adaptations, so they didn't
01:11become an easy quick snack for snakes, coyotes, hawks, foxes, and other big animals going
01:17after them.
01:19They 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, it's not what you
01:30would 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
01:43have them.
01:45But millions of years ago, it was a different story.
01:49Some of the most fearsome dinosaurs were covered in feathers, too.
01:53Of 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 1.5 tons and was covered in a shaggy coat of filaments
02:06known as protofeathers.
02:09These feathers were not used for flying, but to stay warm or attract mates.
02:15Or 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, like some sort
02:27of bird.
02:28Many of their dino-relatives had pretty long feathers all over their forearms, together
02:33with downy feathers that were spread across the rest of the body.
02:38This works for most of the meat-eating dinosaurs or so-called theropods.
02:43There were tiny ones, with a tail fan full of feathers, or those with shiny feathers
02:48in 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,
03:05they 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, like Anchiornis, whose body
03:19was almost entirely black.
03:22It's reminiscent of a bird with wings and fluffy tail feathers on its hind legs, together
03:27with a pretty long tail that could fan out.
03:31This fella had white stripes along its wings, too.
03:34It also had a brown head crest.
03:37This one was perhaps there as a display or used to communicate with other Anchiornis
03:41dinosaurs.
03:44And check out this one!
03:46It also had a bristly tail and different markings on its body.
03:51Thanks to the fossils they found, researchers have been able to reconstruct the appearance
03:55of this dinosaur, giving it so many details.
03:59Not 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 and most likely used their feathers
04:10for displays.
04:12There was a discovery in Canada that revealed one type of dinosaur had a fleshy crest on
04:17its head, like a rooster's comb.
04:20Scientists think this crest was likely used as a way to attract a mate or show off to
04:25other dinosaurs.
04:28Then there's the scariest of them all in the dinosaur kingdom – the T. rex.
04:34Can you imagine this one in a birdie version?
04:37Also, you may have seen pictures of T. rex with its big sharp teeth and its jaws wide
04:42open, kind of always ready to bite into its prey.
04:46But these images might be completely wrong.
04:50Some recent research tells us these top predators might've had something that we take for
04:54granted in almost all land animals today – lips.
05:01Think about it.
05:02When 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, theropod dinosaurs,
05:12were the same way.
05:14Well, not quite.
05:17Researchers looked at fossilized dinosaur skulls and compared them to modern reptiles,
05:23and found out these dinosaurs likely had soft tissue around their mouths that functioned
05:28like lips.
05:30Scientists learned this while studying small passageways in the upper jaws of dinosaur
05:34skulls – something 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
05:48jaw near the teeth.
05:51Let's examine 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 erodes
06:02more 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.
06:17Based on this, scientists believe theropods with long sharp teeth, like T. rex, could
06:22also close their mouths with their teeth inside.
06:25The teeth of theropods and monitor lizards are similar in size, and monitor lizards can
06:31close their mouths completely.
06:33Therefore, it's likely that theropods also had lips that allowed them to fully close
06:38their mouths.
06:39However, it's not known if they wore lipstick.
06:45Interestingly, the study also revealed a neat row of jaw foramina in a pretty cool extinct
06:52early cousin of crocodilians.
06:54Also, lips may have been present in the earliest archosaurs, a group of reptiles that gave
07:00rise to dinosaurs and crocodilians.
07:03Now, this might not seem like a big deal, but it truly changes how we think about how
07:08these dinosaurs ate.
07:11If 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.
07:21Some still believe differently, saying T. rex and other theropods had flat scales like
07:26crocodiles all the way down to the edges of their jaws.
07:30So I guess the mystery of dinosaur lips continues.
07:35You might be wondering, did sauropod dinosaurs like the titanosaur have feathers too?
07:42Some scientists believe all dinosaurs, including sauropods, had feathers.
07:48Just 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, the chances of
08:04finding those of sauropods or similar dinosaurs are definitely lower.
08:10Plus there's a chance big dinosaurs that lived in warm weather didn't have feathers at all.
08:17Many of these feathered dinosaur fossils have been found in China.
08:21These fossils have helped us understand the transition from feathered dinosaurs to birds.
08:28Because birds could be the only animals that survived and are around today that are directly
08:32related to dinosaurs.
08:34I wonder what happened here?
08:37It could be that some kinds of theropods started hiding in trees more while searching for food
08:43and protection, so their bodies evolved to become even smaller to survive harsh conditions
08:49and dangerous predators lurking after them.
08:53But still, it's a transition from the most incredible predator the animal kingdom has
08:57seen to squawking chickens.
09:00Talk about how evolution mostly moves animals forward!
09:04Hey, stop it!
09:05I didn't mean it!
09:09That's it for today!
09:10So hey, if you pacified your curiosity, then give the video a like and share it with your
09:15friends!
09:16Or if you want more, just click on these videos and stay on the Bright Side!
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