When it comes to prehistoric critters, it can be real easy to point at any large, scaly beast and call it a dinosaur. But there are a lot of prehistoric critters that were not dinosaurs, even during their heyday. In fact, dinosaurs are only a small fraction of the animals that walked around during the “Age of Reptiles”.
Unfortunately, sometimes even “educational” books and movies will lump in the other critters in the same group as the dinosaurs. So how can you tell which is which?
Let’s have some fun with a little quiz. Can you tell me which critters are the dinosaurs, and which ones aren’t?
First off, a handy dandy dino checklist.
Dinosaur hips make for straight, sturdy legs under their bodies, just like mammals. Unlike other reptiles that walk with legs splayed out, dinos tend to walk with one foot in front of the other, just like we do.
Dinosaurs all lived in the Mesozoic period up to the present day. Birds, of course, can be seen outside your kitchen window. All other dinosaurs, or non-avian (not-bird) dinosaurs, appeared in the Triassic, reigned all through the Jurassic, and met their end at the Cretaceous.
All Dinosaurs share the same latest common ancestor- the great-great-great-grandaddy of Iguanodon and Megalosaurus. Iguanodon is a giant, spike-thumbed plant-eater from Cretaceous England. Megalosaurus is a meat-eating distant cousin of T-rex, from Jurassic England.
Fun Fact on that last one:
Sir Richard Owen coined the name Dinosauria based on Megalosaurus, Iguanodon, and Hylaeosaurus (a plant-eater built like an armored tank, but without the club-tail of more popular armored dinos. Cretaceous England).
All three of these critters can still be seen today at the Crystal Palace in London, where sculptures were built based on the latest scientific knowledge of the 19th century. It’s in a sad state compared to the grandeur of its golden years, but it’s still on my bucket list. 😀
Dinosauria is often translated from the Greek as “Terrible Lizard”, but it can also translate to “Fearfully Great Reptile”. Owen seems to have named the creatures based on their awesome size and how majestic they must’ve looked in life. Not on their “terrible” teeth, spikes, and claws.
Now that you know the features that make a dinosaur, let’s get started! 😀 I’ll leave the answers for the very end, so that you can test yourself.
First up, Bowser the Ceratosaurus! He’s big, and lived in Jurassic North America. He has a nice beefy tail with the muscle power to move his legs forward, one foot in front of the other.
Look who’s come out of hiding…Nessie the Plesiosaurus! Those flippers are great for gliding through shallow Jurassic seas or paddling in murky rivers. You’ll find her swimming around in Jurassic England.
Here comes Bella the Camarasaurus! She’s a big girl, and proud of it, but she has no problem moving all that weight around. Her legs are like pillars, strong and sturdy under her body. You can find her in Jurassic North America.
Why hello there, Dan the Dimetrodon is here for a special visit. He came by all the way from Permian North America, an earlier time than the Triassic period.
Twig the Compsognathus is a little guy, only as big as a turkey, but that just means he’s extra fast. He runs like a roadrunner, and easily snatches up splay-legged lizards. You can find him in Jurassic Germany.
(quick note: there are rumors of scale patches on the legs and tail for this little guy, but I haven’t been able to find the papers describing them. So I’ve given him feathers based on a close cousin.)
Flipper the Ichthyosaurus comes in with a splash! But what is he? You can find him cruising Asian and European waters during the Triassic and Jurassic periods.
Tango the Archaeopteryx loves to sing and dance, and no lizard can dance like Tango can! He’s got the finesse of a duck and the enthusiasm of a parakeet. You can find him and his fancy feathers in Jurassic Germany.
Here comes Tigger the Pliosaurus with a big grin. An apex predator in the water, this big guy would’ve made the Jurassic seas around Europe and South America a dangerous place to be.
Are those…Turkeys? Why yes, yes they are. They’re showing off their festive plumage by strutting with one foot in front of the other. You probably see one at your dinner table on occasion.
Ron the Rhamphorynchus has dropped by to see you. Those teeth look a bit vicious, but he’s just an excitable fuzzball really. You can find him soaring through the Jurassic skies in Germany.
Think you got them all? Let’s check and see!
Bowser the Ceratosaurus is a dinosaur! He stands upright with his legs under his body, he’s a theropod (who were the theropod dinosaurs?), and he lived during the Jurassic period- the middle of the Mesozoic era.
Nessie the Plesiosaurusis not a dinosaur! She lived at the same time as many dinosaurs, and she’s big and scaly, so I can understand why she’s often thrown into the pile. She’s a marine reptile called a plesiosaur, and she’s actually the first discovered, so she got to name the whole group!
Bella the Camarasaurus is a dinosaur! She stands tall and straight on legs like pillars, and she lived in about the same time and place as Bowser.
Dan the Dimetrodon is not a dinosaur! Dan is quite a few million years too early, with the biggest mass extinction in Earth’s history between him and dinosaurs. But if you don’t know what time he’s from, then you can see that his legs are sticking out like a croc, instead of underneath his body. But he’s not a croc either. He’s a synapsid. Mostly that’s a fancy term about the skull. I’ll get to that when I’m working on the Permian period. 😀 That said, I totally get why people would think it’s a dinosaur. I mean, it’s everywhere! It’s even on my kids’ favorite oatmeal, y’know the one with the hatching dinosaur eggs?
Flipper the Ichthyosaurus is not a dinosaur! He’s also not a fish, dolphin, or prehistoric whale. He’s a marine reptile called an Ichthyosaur, and he was the first of his kind discovered, so he got to be the namesake of his group. Since the name translates to “fish lizard” or “fish reptile”, then there’s no surprise when people call him one. The reason he looks like a dolphin is because the fishy/dolphin/shark body plan is so perfect. For an animal that is born, lives, and dies in water, then his body shape is perfect.
Fun fact: Plesiosaurus was given that name because her kind is “nearer to dinosaurs” than Ichthyosaurs like Flipper.
Tango the Archaeopteryxis a dinosaur! Few deny the birdiness of this critter. Where some people get confused is the dinosaurness of birds…but this little guy is a lovely mix of both. But now you’re getting to know the drill. Feet underneath the body and supporting his weight. Jurassic period, “golden age” of dinos…etcetera, etcetera… 🙂
Tigger the Pliosaurus is not a dinosaur! It’s starting to look like there are no swimming dinosaurs. There are always exceptions to the rule of course *cough*Spinosaurus*cough*, but in general, you don’t really see dinosaurs getting specialized for a life in water. Tigger is another that gets to name his own group. The Pliosaurs. They were marine reptiles that thrived in the Jurassic and into the Cretaceous, but died out alongside the dinosaurs.
A Turkey is a dinosaur! Yes, when you sit down for that turkey sandwich, or prepare for that Thanksgiving feast, you are about to eat a dinosaur. All birds are members of the theropod group (take a look at Bowser up there). Want more info? I’ve got a post on birds over here.
Ron the Rhamphorynchus is not a dinosaur! Like the marine reptiles, his kind lived at the same time, and so are always being tossed onto the same pile. Ron is a Pterosaur, a flying reptile that is actually in the same family tree as crocs and dinosaurs, but not so close that he’s mixed in with the dinosaurs. Pterosaurs were usually pretty good at walking, but they didn’t have the same hip as dinos.
How did you do? If you didn’t do very well, don’t feel too bad. There’s a lot of misinformation out there, even from sources that are supposed to be educational. And really, it’s a lot easier just to call them all dinosaurs, instead of having to remember all the different names for the different groups. 🙂
Quick Question: What’s your biggest source of info about dinosaurs? Jurassic Park? The news? Dino obsessed friend or kid? Your own research? I’d love to hear from you in the comments! 😀
Meet Tango. This bird likes to party, and loves being the center of attention even more!
Tango is a pretty good example of when you should check with your neighbors before you choose your pet. Of course, if you live out in the sticks like I do, then it doesn’t matter so long as you don’t mind going deaf.
Ok, ok, I exaggerate. But really, unless you like a whole lot of this going on, I’d reconsider a quieter critter.
I’ve got profile pictures for all the critters on the critter page! (I’m super super excited, because that’s the most obvious sign of my progress so far XD )
Speaking of profile pics, notice how Tango got a shiny updated one? (hint hint, nod nod)
Tango is excited to see you! Say hello Tango (Weeooh! Chip-chip!). He gets pretty excited when he meets new people, so we’ll see if he’ll let us talk for a little while. (weep-weep!)
A rude (but necessary) disclaimer interrupts this post to say…
I do the best I can with research, but I’m a stay-at-home mom who’s always had a passion for all things prehistoric. I’m not a paleontologist, and I don’t have access to all the scientific papers available. But I try my best to keep up to date, and all my illustrations reflect this.
That said, all the drawings in the A&S post series are quick doodles to illustrate a point, with not as much reference as I usually use, so there are plenty of inaccuracies for you to point out for me. 😉
Thank you disclaimer, you can go bother someone else now.
Oh, and one more thing, before you start seeing the name Archaeopteryx everywhere (and trying to pronounce it in your head), here’s a quick pronunciation guide. I wasn’t sure myself, so I thought I’d share it!
1. Ok, So What is He Really?
You probably recognize Tango from just about every book on dinosaurs out there. They tend to announce him as the “first bird” a lot, and 8-year-old me would think, “then what’s a bird doing in a dinosaur book?”
So what is he, a dinosaur or a bird?
Well if you read last week’s post on birds, then of course you might say he’s a dinosaur, since all birds are dinosaurs anyway. But we’re being more specific this time. 🙂
So let’s get into something called cladistics.
To put it simply (partly for my own benefit because I’ve just started getting my hands dirty with this stuff)…
cladistics is how scientists determine where an animal goes on the family tree, and how we explore animal’s relationships with each other. Animals in any particular group are determined to have shared traits and characteristics, and must therefore have a common ancestor.
For example. All cats, wild and domestic, have a number of traits that are the same, so then they must have a single common ancestor that gave them all those traits. Very much how your great grandmother passed down her characteristics to her daughter, grand daughter, and great-granddaughter. 🙂
I’ll start off with a group of dinosaurs called Theropods. They’re the ones we typically think of as walking on two legs, and generally meat-eaters, like T-rex. 🙂
Nestled inside the Theropod box are many groups. You can think of them as smaller boxes inside the big box. The box that we’re taking out of the Theropod box will be a group called Coelurosaurs (seel-ooh-row-saurs).
Most of the critters in this group are possibly feathered, and include the “ostrich dinos”, “velociraptors”, T-rex, and mostly all the animals we would think are birds at first glance.
Inside the Coelurosaur box are other boxes, including the one with T-rex inside it. But as much as I like T-rex, we’ll be ignoring his box for now and looking at a box labeled “Maniraptora”.
This box has animals that are more obviously bird-like. If we were to see them in life (vs. the Jurassic Park version) we would think “bird” or “very strange bird”. Very strange (and giant) when it comes to Therizinosaurus, but that’s a subject for another day. 🙂
Inside the Maniraptora box there are more boxes. These boxes get reorganized about twice a year, because now things start getting a little difficult when it comes to separating true birds from non-avian dinosaurs.
We’ll find Archaeopteryx in a box labeled Avialae.
This box includes all modern birds and their direct grandparents and great-great-grandparents. It also includes the toothy birds, and sometimes Troodontids (think mini raptors, but even more “birdy” and kinda like owls).
Whew! Thank you for sticking with me for all that. 🙂
The final verdict according to the family tree…
Archaeopteryx is a bird. 😀
And yes, it’s a dinosaur too, because birds fit in the “Dinosaur” box.
2. But is He the First?
Tango’s gotten a lot of press over the years as the “first bird”, but is he really the first? It depends on if there was another dinosaur as closely related to modern birds as possible, but earlier in the timeline.
And it turns out there’s another one that’s earlier in the timeline…
Most of us may look at Tango and see a birdy critter with big wings- of course he can fly! But wait, not so fast. Flight, as you know, is a very difficult skill to master, and just because an animal has wings doesn’t really mean it has all the other things it needs to fly.
So poor Tango’s been in the middle of an argument.
The wing feathers are asymmetrical, just like modern birds. This gives the wings a more aerodynamic shape, which is useful for flying.
Tango’s muscles are a bit weak, and his tail is not the best for flying, but in nature, whatever you’ve got is good enough to thrive where you’re at. Tango may’ve been just good enough a flyer to get across the river, from one branch to the next. Landings were probably not his strong point.
I’d be really curious to see what paleontologists would find if they compared Archaeopteryx flight muscles with those of a hoatzin. 🙂
That’s all for now folks! Say goodbye Tango…:D
Quick Question: Do you remember your first “encounter” with Archaeopteryx? How has the media, books, and maybe your own research affected your thoughts of birds as living dinosaurs? I’d love to hear from you in the comments!
If I asked you, “What is a bird?” What would you say? For most of us (at least for me) the first things that come to mind are feathers, a beak, and usually flight. Oh yes, and lays eggs. If you look out your window, go on a hike, or visit the zoo, it’s easy to recognize birds for what they are.
But what if we went back in time a few million years? It may be harder to pick out the bird from the…not bird, than you think.
Let’s say you’re picking your way through the thick undergrowth of a pine grove. You hear twittering from a branch above you, and you look up to see the tiny singer. It looks like a bird, it acts like a bird, but when it opens its beak to sing you notice tiny teeth.
Is it a bird?
Let’s try another one. Another place, another time.
You look up when you hear the sound of flapping wings above you. At first glance it looks like a bird, but then you notice those long tail feathers are not just feathers. Instead of a long train like a parrot or peacock, this fan is supported by a long tail. A closer look and you notice that this bird has claws on its wings, and a beakless snout with tiny teeth.
Is it a bird?
Let’s take a look at one more.
In another place, another time, we peak through the branches to look out into a clearing. Pecking at the undergrowth is something that looks a bit like an ostrich, or maybe an emu. Shaggy feathers, a toothless beak, and feather-duster wings all look like a big, flightless bird. But no bird has a long tail like that. That tail looks like it belongs on a lizard, if only it wasn’t covered in feathers.
Is it a bird?
At first glance, all three look very much like birds.
The first is an early bird called Sulcavis, which lived around the same time as T-rex, in China.
The second is Archaeopteryx. More dinosaur than bird, and from a much earlier time in Germany. It’s often reported as the first bird, but there are earlier cousins that are more bird than dinosaur.
The third is Gallimimus. If you’ve ever seen the original Jurassic park, these are the featherless “ostrich dinosaurs” that stampede around the heroes. Fossils now tell us that these dinosaurs would look very much like emus and ostriches with tails. 🙂
So how do we know which is which? We can’t define it based on feathers, eggs, or flight. In fact, paleontologists argue quite a bit on exactly what makes something a bird or a dinosaur.
The best answer I have on this insanely complicated subject (because let’s face it, I’m no expert. I’m just a couch enthusiast 😛 )…
All birds, past and present, are dinosaurs. But not all dinosaurs are birds. 😉
Even this handsome guy. I love the thought of dinosaurs running around my yard and giving me eggs.
Quick Question: What do you think about the relationship of birds and dinosaurs? The discovery of more and more dinosaurs with feathers has turned into a rather hot topic, with passionate feelings on both sides.
Me? I think our entire natural world (and our place in it) is amazing beyond words, so I’m cool with anything the latest research has to dish out. Birds jumping on the dinosaur wagon just adds a whole new dimension of awesome. 😀
When you think of an animal with wings, you usually think of something that can fly right? Bird is one of the first things that pops in my head, and when most of us think of birds, we usually think of birds that fly.
But not all birds fly. Of course, out of all the birds that can’t fly, what’s the first thing that comes to mind. Penguin? Ostrich? Kiwi?
Then there’s another category (wait, there’s more?).
Those are the birds that don’t usually fly, the sort of bird that we’re always a bit surprised to hear can actually fly.
Like turkeys. 🙂
So how does this apply to prehistoric critters? Well, there are times when paleontologists aren’t so sure if a bird or other feathered dinosaur could fly. And then there are the times when paleontologists are so sure something could not fly, but then later on down the road new evidence shows up that it might…
So how can you tell for sure?
This is where the guessing game gets fun. We take a look at all the evidence we have, look at modern animals to get more insight on certain relevant details, and then propose our best hypothesis.
Next week, we’ll take a look at one of these discombobulating critters. Until then, enjoy the adorkable awkwardness of a hoatzin clambering about (a lovely bird of the South American Amazon). Landings don’t look like their strong point. 😛
Quick Question: What’s the first bird you think of when I say “bird”? I’ve got kiwis and penguins on the brain since I’ve written this post, but I do love the little songbirds that sing around our yard. I’d love to hear from you in the comments!
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