Hello there! Alfred is super excited to see you, and look at how curious he is. Do you own a cat or dog? Because he seems to think you smell good. (stay back Alfred, be nice). Here we go, I’ve got a nice ball of cheese and bacon here. He’ll love it. Here Alfred, go get it!
While Alfred gets the ball, I can share this lovely disclaimer. Que elevator music…
I do the best I can with research, but I definitely don’t claim to be an expert. I try my best to keep up to date, and all my illustrations reflect this. (thank you internets, and to all hard-working paleo-nerds who are kind enough to make your papers open source!) 😀
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. 😛 Elevator music fades out…Oh and here comes Alfred! Looks like he wants more…
There we go, good boy Alfred!
Now Alfred here is an Allosaurus. He’s young, so only about 12 feet long so far, but he’ll grow to be a lot bigger. Not as big as his wild cousins though, a few of them could be as big as T-rex! (very few, gotta be old to get that big, and most dinos have a live fast, die young policy)
1. On Scaly Skin vs. Feathers
So you see Alfred here has these lovely bright yellow and forest green scales, the colors of youth. (They’ll mellow out a bit when he gets older, like monitor lizards do)
Also like a monitor lizard, you’ll notice that most of Alfred’s scales are quite small, with a rather pebbly texture. They get a bit larger and thicker on his back, which is good since adult Allosaurus tend to get into quite a lot of tussles with each other. But most of his scales have that nice cobblestone look to them.
Like this guy, remember him from last week’s post on feathers and scales?
Short answer as to why Alfred has scales…there’s a young Allosaurus with preserved scales somewhere on it’s body. (Unfortunately the report didn’t say where)
Long answer was so long I made a post out of it…To Feather or Not to Feather Your Dinosaur, That is the Question. (The komodo dragon above was laying around in that post. So was this gal, she’s a monitor lizard. 🙂 )
2. Getting Comfy…
Looks like Alfred’s all worn out from chasing after that giant, cheesy bacon-ball. He hasn’t quite grown into his adult silhouette yet. He’s still young enough to think he can chase after stuff, but he’s starting to get to an age where it’s getting hard to make those quick turns.
When he fills out his more barrel-chested adult figure, he’ll be spending quite a bit of his leisure hours (think energy-efficient) laying around. Since his body is a bit taller than it’s wide (more lanky cat than double-wide gator), it’s more relaxing to be lounging on his side.
Of course, that doesn’t mean he can’t do other things to relax, even things that may surprise us (ever seen a large horse roll? It’s hilarious 😀 ).
Oh, and here’s that horse… 😀 I can totally picture some “duckbill” dino doing this.
3. Where are His Teeth?!
I hear ya, I wondered the same thing when I looked up pictures of Komodo Dragons and monitor lizards. But wait, what does that have anything to do with it?
Pete will help us out here. I know Alfred looks a little awkward, but he’s actually quite comfy. Ah- I’ll let Pete tell you the rest…
“Thank you. Yes, Alfred is quite at ease here. I’m not heavy to him at all, and he weighs at least a good 300 pounds at this age. So he doesn’t mind a bit.
I’m tilting his head back very gently- show us your teeth there Alfred, that’s it, nice and easy.
See this is the biggest difference between a domestic Allosaurus like Alfred here and a wild one. Look how completely relaxed he is. He’s not fighting me at all, and even his eyes are closed, look at that. (Alfred makes a gurgly, kinda purring sound in his throat)
Anyhow, I’m holding onto his lips here so I keep my fingers out of his mouth. My fingers can look a bit like treats, so I’ll be sure to keep them right at the edge here, at the gums.
All this, the lips, the gums, the saliva- it all keeps his teeth nice and moist. Dinosaurs have a healthy coat of enamel on their teeth, same as your teeth, and the key to healthy teeth is to keep them moist. Even better if you can give your teeth a constant bath of saliva.
Yes, drool is essential to healthy teeth!
Now Alfred will lose his teeth and grow new ones, just like crocodiles and alligators do, but if you look closely at these teeth-they’re serrated. They’re like steak knives- not like the cone-like teeth of crocodiles.
Thank you Alfred, you’ve been quite patient. Here’s some jerky.
But crocodiles don’t need serrated teeth. They’re eating different things, they have a different habitat, and different diet, they’re eating in a completely different way. Alfred has teeth like a bone saw.
Ever cut a roast turkey with an electric knife? That’s what Alfred’s teeth are doing when he eats, so they need to stay sharp, and they need to be strong in his mouth. So the gums hold his teeth, and his lips keep them nice and moist so they stay strong and don’t get brittle.”
Thank you Pete, and Alfred. Just for comparison, here is a crocodile monitor lizard.
My first thought, “Where are the teeth?!” Then I noticed those sharp white triangular things inside the lip. Also interesting is that it looks like there are pockets for the bottom teeth to slip into. 🙂 Here’s the skull of the same animal…
They look quite different from the other picture don’t they? Almost, shall I say, dinosauresqe? Take a look at an Allosaurus skull. 😀
The one and only skull I could find that doesn’t have its teeth halfway falling out of their sockets (it happens when the dead critter decays). Jason has many more pictures of the Allosaurus mounts at the American Museum of Natural History, and I’d highly recommend you check out his blog post. You’ll also discover all my errors and where I need to fix Alfred. 😀
Quick Question: Help me find what I need to fix! If you wouldn’t mind checking out this blog post on Allosaurus, you’ll get to see some great pictures of excellent mounts, and you’ll see what I have to correct in my illustrations of Alfred.
I’d love to hear from you in the comments! I’ll be posting a comment on how many I find, and let’s see if we come up with the same ones or more. 😀
Every time I turn a corner, there’s a new feathered dinosaur to join the line up of “enfluffened” critters. T-rex, Velociraptor, Gallimimus…iconic dinosaurs from movies like Jurassic Park have bonified proof of some sort of floof covering their bodies. Even the plant eaters are getting floofy with critters like Hypsolophodon and Kulindadromeous.
Don’t get me wrong, I love feathery dinosaurs, and I’m a pretty big fan of a huge, fluffy, grizzly-hawk T-rex (that’s just epic 😀 ).
But sometimes artists can take this idea a little too far. “Woolly” Arctic ceratopsians (“three-horns” & cousins), and spike-tailed stegosaurus with porcupine quills is going a bit far on the speculation even for me.
There’s a fine line between reasonable speculation, and downright fantasy.
But let’s pause for just a moment. I know that a lot of paleoart is speculative, a way of illustrating hypotheses proposed by paleontologists, but there’s also a surprising amount of stuff we do know.
What I mean to say is…
The stuff you see in paleoart is not some wild guess, and just because the critters are long dead doesn’t mean anything goes. I’ve described the process of reconstructing prehistoric critters in my blog post series, Fleshing Out the Bones. You can click this link to read more on that if you’re interested.
So how do you decide if you’ll give your dinosaur feathers or scales?
Let’s take Allosaurus and my illustrations of Alfred as an example. How do I know if he should be covered in feathers or scales?
Step 1: What’s the evidence?
Are there any fossils of skin impressions or feathers? In Alfred’s case, yes, yes there is. 😀 I don’t know if there are any published papers on this, but here’s a link that describes the preserved skin on a juvenile Allosaurus. It was discovered during preparation of the fossil.
Based on the fossil, the young Allosaurus had small scales about 2-3 mm in diameter. So tiny, pebble-like, non-overlapping scales, rather like the sort you see on gila monsters and monitor lizards.
But What if I didn’t Have Fossil Evidence? And for some, a patch of skin in one part of the body is not enough. Afterall, in some dinosaurs you get quite the mixture of feathers and scales. Compsognathus, for example, has close relatives with evidence of “full floof”, but the critter itself has scale impressions on its tail and legs.
Step 2: Look at Their Relatives.
Like we just did with Compsognathus up there, we can look at close relatives in the same family to figure out the scale/feather thing. In the case of the compy, the possibilities can get even more confusing, but let’s go back to Alfred.
If you go back to last week’s post on Theropods, you’ll see that Allosaurus is in the family Carnosauria. One rather infamous member of this group is Concavenator. It has what looks like quill knobs on its arms, which in modern birds are small bumps on the bone where ligaments for flight feathers attach.
The “quill nobs” of Concavenator are a subject of much discussion. Duane Nash has a particularly interesting interpretation over at his blog, Antediluvian Salad. I’m not a fan of how monstrous he illustrated the poor critter, since I tend to see the beauty even in Earth’s homeliest of creatures, but the article is a very interesting read, and I’d recommend you check it out. 🙂
Step 3: Where is it in the Family Tree?
Pterosaurs are about as closely related to dinosaurs as alligators and crocodiles are. Neither are dinosaurs, but they’re all in a much larger group called Archosauria.
Because of this relationship, it’s a pretty big deal if the fuzzy pycnofibers on pterosaurs are the same as the fur-like fluff on certain dinosaurs (like Compsognathus & cousins).
Why? Because it’s much simpler to assume that the great-grandmother of dinosaurs & pterosaurs had the fuzzy feathery fluff.
Much more complicated to assume that dinosaurs & pterosaurs developed the same fuzzy feathery fluff each on their own.
What’s easier? Learning with a friend from a teacher, or each of you studying on your own? Not exactly the same, I know, but I think you get my drift. 🙂
With this in mind, let’s see where Alfred is on the family tree, and how far away he is from the main branch or outlying branches.
Alfred is on the branch labeled Carnosauria. This is quite a ways away from the base of the branch, with many critters in between that are known to be scaly. So feathers from that direction are very unlikely.
Once proof of scales appears we don’t see any real evidence of feathers until we get to the branch labeled Coelurosauria.
Final Verdict: Allosaurus is More Likely to Have Scales, Based on Current Knowledge.
So what would that look like? The scales are small and non-overlapping in our sample, so let’s look at Komodo Dragons and Monitor lizards. 😀
Bonus Question: With this research, I think Alfred could use a bit of a makeover! What would you prefer to see?
- A much needed nap after chasing that butterfly
- Curious Alfred is curious
- Is that the dinner bell?
Which scenario should I use to revamp his profile picture? I’d love to hear your answer in the comments! 🙂
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…
Aurornis xui is a bird from Jurassic China, in sediments that are older than the rocks Archaeopteryx are typically found in Europe. Pascal Godefroit et al. write in their paper on Aurornis that their studies determined it as the…
- Earliest bird
- It confirms that Archaeopteryx was indeed a bird
‘Nuff said. 🙂
3. Can He Fly?
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.
Can he fly, or is he stuck clambering up into the branches to jump off and glide? Here’s why many paleontologists believe he can fly…
- A few amazing specimens have a wishbone (check out pictures of almost all 11 here!)
- 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. 😀
I’d love to hear your thoughts in the comments! 🙂
Hi there! Terry is here with us today, a rather odd looking critter isn’t she? If I asked you to tell me what she is, what would your answer be? Flying dinosaur? Terradactyl? Pterosaur?
If you said Pterosaur then clearly you’ve done your homework. If not, don’t feel bad (I’m not pointing fingers), because the sad fact is that most books, movies, toys, and pretty much anything to do with dinosaurs always lump Terry and her many relatives into the same pile.
Terry is a Pterosaur (Don’t mind the P there, it’s confusingly silent), a group of flying reptiles closely related to dinosaurs. To be specific, her wild cousins are Pterodactylus kochi. Pterodactylus is the pterosaur, where we get the name for the whole group. So now you know she’s special. 😀
1. Is that…fur?
Terry, like all pterosaurs, is covered in a fuzzy layer of pycnofibers. They’re made of the same keratinous proteins as our hair and fingernails. But they appear to be hollow inside, which makes them much more like feathers than fur.
I say “appear to be”, because not everyone agrees. Most of the fossils are a bit squashed, and even the 3d fossils can be hard to tell if what fills the space inside was part of the living animal or just more of the fossil (or a part of decomposition after the critter died, but before it fossilized).
Last week we saw the basic structure of a feather. If pycnofibers are indeed hollow, then that could mean that they are similar in structure to feathers.
Terry and her many relatives are related to dinosaurs in the same way that crocs are related to dinosaurs (They are all Archosaurs). A bit like a great aunt.
Since many dinosaurs are known to have feathers of various kinds, it would be pretty significant if pterosaur pycnofibers are determined to be feathers as well.
How significant? More fluffy dinosaurs! It’s possible that the earliest dinosaurs had a coat of fur-like feathers. 🙂
2. Hard Beak or Fuzzy Snout?
Now I’m not quite sure where I first heard of the idea of hard-beaked pterosaurs…I think I remember Petrie from The Land Before Time had a beak. Come to think of it, I guess there are plenty of interpretations with beaky pterosaurs, but I’m not sure how many are based on fossil evidence.
So why does Terry have a soft, fuzzy snout?
The fossils don’t have a beak. In fact, in several beautifully preserved ones we see only soft tissues, complete with a soft crest and that lappet on the back of head. There’s a lovely diagram showing how clear the fossil is over at Mark Witton’s wonderful blog. I’d highly recommend you check it out, because he’s an excellent artist, and an expert on all things pterosaur. 🙂
Terry’s friend on the left is a Rhamphorynchus (that’s a mouthful, sorry, let’s call him…Ron). Some illustrate Ron and his wild relatives with just the toothless tip of his snout with a beak, but I’ve based mine off of Mark Witton’s lovely illustration.
Honestly, it’s hard to imagine those crazy teeth with any kind of soft tissue, and that seems to be the argument for a hard beak over the bone.
3. The original pole vaulting masters
Pterosaurs had powerful wings, but their legs weren’t really strong enough to jump up to fly like birds. So does that mean they’re helpless on the ground?
Not at all, look at Terry scamper around!
Pterosaurs were Earth’s first pole vaulting masters. Their powerful wing-arms were strong enough to push their bodies (even the biggest ones) up into the air. Mark Witton proposes that even the largest, giraffe-sized pterosaurs could lift off from the ground. Many could probably take off from the water!
Helpless? I think, not. 🙂 Here’s a quick video so you can see it in action. 🙂
How is it possible?
Unlike birds, pterosaurs have most of their muscle dedicated to their wings. Birds need enough muscle in their legs to jump up before flapping, while pterosaurs pole vault into the air with the same power they use for flying.
So no need to jump off a cliff or wait for warm updrafts of air. 🙂
Quick Question: Ah, the nostalgia of so many movies and documentaries…I must say I still rather like the leathery, cliff-clinging bats in Fantasia (so many great retro-saurs in that one). Are there any pterosaurs from books or movies that have colored how you see these animals? 🙂 I’d love to hear your answer in the comments!
Hello there Steggy! She’s followed me here because she wants the bucket of tasty fern balls I’ve brought with me. That works out nicely, since she’ll stay here and munch while we point and chat about her for a few minutes. Just like when we talked about Ajax last week, I’ll stick with 3 research tidbits for now, to keep things short. 🙂
1. Soft or hard-shelled turtle?
Steggy’s a bit smaller than the average wild stegosaurus, but she’s still quite a bit taller than we are. If you reach up on your tip-toes you might be able to touch the biggest of her plates, the one right above her hips there.
There’s been some speculation in recent years on if these plates were hard and covered in keratin- like a turtle’s shell or cow’s horn- or if the plates were soft and covered in scales or skin.
I did a bit of digging (research wise), and came across this lovely gem of information written by Darren Naish. He cites a paper provided by Christiansen & Tschopp (2010), who reported a continuous sheath-like covering on one of the plates they referred to another spiketail known as Hesperosaurus.
So there you have it. Hesperosaurus is a very close cousin of Stegosaurus, so in the realm of phylogenetic bracketing that makes it more likely that Steggy had a smooth, hard sheath of horn on her plates and spikes.
2. Armed to the teeth.
The same Hesperosaurus described had another very rare insight on spiketails- fossil skin. As you can see on Steggy here, most of her body is covered in small, non-overlapping scales, called tubercles. They look a bit like pave stones don’t they? Now look up here, a bit higher up on her side. Interesting isn’t it?
Steggy has some pretty tough scales. These large oval scales are called osteoderms, just like the large, hard scales on the backs of crocodiles. They’re covered in keratin, like our fingernails, and they do a pretty good job as armor. I’m sure Alfred‘s wild relatives had a tough time munching on wild stegosaurus. 🙂
- thick skin with larger, armor-like scales (also useful for prickly plants) You can find the abstract for the paper describing the skin here.
- Large, horn plates protect the spine
- Bony neck armor protects neck from predators and prickly plants
- Muscular tail that’s flexible enough to jab at hard-to-reach places, like between a predator’s legs. Just take a look at this article about a time the allosaur lost the fight…And check out this article on exactly how lethal a blow from this kind of tail can be (using a different spiketail cousin as a model)
- Short front legs can bring head lower to the ground (harder to reach) and spiky end up, or push the body up to swivel on powerful hind legs. Awesome for quick, sharp turns. No way a hungry predator can get to anything soft and vulnerable if that spiked mace is always between it and the stego.
3. She might not be the sharpest rock, but she’s one tough cookie.
Steggy might have a brain the same size as a dog’s, but she’s not nearly as dumb as movies and the media would have you think. (I’m looking at you Spike, in The Land Before Time). I think most encounters would not have ended up like the stego in Disney’s Fantasia (which is totally what inspired my love for them in the first place 🙂 )
With all that armor, and tons of fossil evidence with some serious dino damage on Alfred‘s wild relatives, it looks to me that spiketails had an attitude to match their prickly array of spikes and plates.
Because of that, I’ve given Steggy a bright warning pattern. Someone told me it reminded her of a skunk, and that’s exactly what I’m going for. Steggy’s color is something that says “stay away!”
Good thing Steggy is a calm and peaceful pet then, a domesticated spiketail. Domestic spiketails have a tendency to be nervous, and spook easily (like horses), but Pete works with her a lot, and hardly anything bothers Steggy now. (horses can be trained like this too)
Just for fun, here’s my reasoning on why Steggy may not be as dumb as you think. A quick check on Youtube brings up plenty of smart tortoises. Yep, after discovering that it couldn’t fit through the pet door, this one figured out how to open a sliding glass door.
Quick Question: Animals do all sorts of crazy things we wouldn’t expect. Do you have a story about an animal or pet that did something unexpected? I’d love to hear your answer in the comments!
First up is Ajax (hi there Ajax! Give’em a smile), because really he’s the first critter of the lot I ever drew, and he shows up in my sketch book a lot. Plus he’s just an all around friendly guy, and anyone knows a brontosaurus (ahem, Apatosaurus) when they see one. 🙂
So what’s science and what’s art? To keep this post short, I’ll cover three main points (there are always more, but we can save those for later). All drawings in these posts 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. But I do have this great
toy model replica to look at when I’m clueless as to how something looks at certain angles. 😉
1. Toothy grin, or soft smile?
For starters, let’s talk about Ajax’s smile in the picture above. There’s a lot of discussion on dinosaur lips- did they have a toothy grin like crocs, or closed lizard-type lips?
On one hand there’s the study by Ashley Morhardt (unfortunately I can’t find it, so I’m relying on 3rd party sources). She compared the skulls of prehistoric and modern animals, and looked at the clues left behind by beaks, lips, etc…and her study suggests that sauropods like Ajax had a face more like a crocodile’s than the fleshy lips of mammals.
This article by Duane Nash on the giant canine teeth of saber-tooth tigers (smilodon & relatives) gives some food for thought. The blog post has all sorts of cool info of what makes a tusk vs. a tooth. 🙂
Ajax’s teeth, like most dinosaur teeth, have a pretty healthy coating of enamel, the same stuff that coats our teeth and makes them hard. Enamel does best when it’s bathed in saliva 24/7, which is why mostly all animals that have enamel-rich teeth have mouths sealed shut by lips of some sort.
Anyway, Ajax eats whatever he can get a hold of. He does replace his teeth every once and a while (unlike our permanent set of adult teeth), but still, it takes a while to get a replacement tooth, so he needs to use each set for as long as he can.
With that in mind, I’ve decided to reconstruct Ajax and the other sauropods with closed, lizard-like lips.
It’s one of those things that we can’t know for sure, because even a mummy can’t give you a perfect picture, anymore than a raisin can tell you what a grape looks like.
2. How far can he stretch?
Oh boy, paleontologists have gone back and forth on this one for over a century. First thin, graceful necks like swans, then BBC’s Walking With Dinosaurs comes out and shows the fruit of research claiming that Ajax & Dippy held their necks out like suspension bridges. They held their heads and tails in almost a straight line, and were unable to lift their heads higher than their shoulders.
More recent work has pointed out that if you add space for cartilage between the bones, then the necks of many sauropods had the flexibility to loop in a complete circle. The brilliant minds behind the SV-POW! team over at svpow.com (always enjoyable to read, but definitely more on the technical side) helped rekindle my love for the long-necked giants by holding their heads high again, and regain neck flexibility by taking soft tissues into account.
In short, we don’t really know. But Ajax would probably have a great deal more flexibility than Walking With Dinosaurs would have you believe. The bendiest part would be the middle of Ajax’s neck, with the ends less flexible.
I always think that animals are more capable than we usually think, so one of Ajax’s buddies has reached back to scratch at an itch on his leg. 🙂
Oh, and those two in the back with the puffy necks…that’s entirely speculative. Something weird was going on with Ajax’s neck though, that’s for sure. 😉
3. I think we need some bigger horseshoes…
Feet, especially the front feet, are usually drawn very, very wrong when it comes Ajax and his relatives. Many artists will slap elephant feet on them and call it a day. But take a look at one of Ajax’s tracks…
Ajax’s legs are like solid pillers, and all the finger bones are wrapped together to form a fleshy, padded, hoof-like structure. Only the “thumb” has a claw, which has some limited mobility depending on the species. Ajax can move his thumb claw up and down a little bit. 🙂
Scientists disagree on how much Ajax could move his wrist. So how far he has his front foot bent at the wrist is a bit speculative.
I’ve done a terrible thing and made his wrist flexible based on an elephant’s range of movement. 😛
Quick Question: Is there anything in the popular media you can think of about Ajax and other sauropods? What common misconceptions do movies like Jurassic Park and The Land Before Time give about Ajax and his cousins? 🙂 I’d love to hear your answer in the comments!