Time to Get Wild! (how we can guess about behavior, and how crazy it can get!)

Now we’ve put all the pieces together and figured out what they mean (sort of).  We’ve done our best to cloth the muscle and bone with fatty tissue, skin, and maybe even feathers.  Now we can really get wild.

 

But surely there’s no way to have any clues on behavior?  It’s all just guesswork right?

Well no, fossils can leave behind clues even for how an animal lived.  Here are a few ways we can speculate (or make an educated guess based on fossil evidence) how wild these critters could get. 🙂

 

Bones & Teeth             

  • Teeth can tell us a lot about what an animal ate, and the rest of the skeleton can give clues as to how it ate.  For example: the slender, notched jaw of Dilophosaurus suggests that it usually ate fast, slippery prey.
Image courtesy of Jaime A. Headden (2011).  Check out his blog to see more beautiful diagrams & illustrations, or if you want to look up more detailed info on all things paleontology. 🙂  Qilong.wordpress.com
  • It’s not fool proof though, just look at pandas and fruit bats.

 

  • Sometimes an animal that looks specialized in one thing is just specialized to survive during hard times. Example: seals that have teeth “specialized” for eating krill don’t only eat krill.  They eat everything they can get their teeth on, with the added bonus of pigging out on krill when they can, just because they can.

 

Articulated Skeletons      

  • Sometimes animals are buried suddenly and quickly.  In especially rare cases, these complete skeletons preserve “candid shots”, moments frozen in time by a collapsing sand dune, mudslide, or drifting down into a deep, cold lake.
  • Click on the pictures for more info. 🙂

 

 

Track Ways                                 

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Photo courtesy of R. T. Bird
  • There are many more tracks than bones, and they offer a unique look at prehistoric animals in action.  Here are a few things we can learn from tracks…
    • How they moved
    • How fast they moved
    • How different animals interact (like traveling herds, or pursuit of prey)
    • Swimming pterosaurs!  There are many tracks of the flying critters swimming.  Interestingly enough, the tracks only have back paw prints.
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Image courtesy of Witton 2013

 

Other Trace Fossils        

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Wikipedia commons

 

  • Fossil dino poo is even better at telling us what a dino ate than its teeth.  The only problem is figuring out who it came from (unless you have a fossil of an animal mid-poop!)
pterosaur_henderson_4090
This little Pterosaur drifted to the bottom of a very deep lake. If you follow the spine with your eyes to just below the blobby rib cage at the base of the tail, there’s a tiny shadow that looks like a cucumber shape. This critter was fossilized mid potty-break. Image courtesy of the Royal Tyrrell Museum of Palaeontology.
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Here’s a closer image. The little arrows labeled cp are pointing to the coprolite, or fossil poo. 🙂 Image courtesy of Hone et al. (2015)
  • Dino burrows give great insight into the social nesting behavior of some dinos.
  • Nests, teeth marks on bones, and dino bottom prints (true story) are all great clues left behind by living prehistoric animals.  Put together, they offer a glimpse into the animal’s story.

 

Modern Family             

  • Since crocs are living relatives of dinosaurs, and birds are dinosaurs, then they are a great place to look for clues.  Take a closer look, and we may get a glimpse of exactly how strange, beautiful, and wonderful dinosaurs could be.
  • The croc family may look tough and mean, but here are a couple of normal behaviors that show how gentle and social they can be.

 

  • Here are a few funky bird dances.  Bright colors not required. 😉

 

Quick Question: Which was your favorite dancing bird? How do you think looking at modern animals like these can inspire our vision of prehistoric animals?  I’d love to hear from you in the comments! 🙂

 

Fleshing out the Bones Series:

Let’s Put Some Skin on That (how much we know, and don’t know, about the soft stuff)

Now here’s where things get a little muddy.  Bones are easy.  They’re hard, relatively common, and all bones that look about the same are going to have similar functions.  Back-boned critters all kinda have the same basic pattern.  Same with muscle.  The only squishy thing with muscle is determining how much is where, then you can figure out the basic shape on top of the bones.

 

But what about skin?  We’re pretty good at figuring out how a dinosaur works on the inside, but what did they look like on the outside?

Here is where a little mud or volcanic ash comes in handy.

When an animal is buried in soft, fine-grained sediment, then the critter’s skin, scales, fur, or feathers leave an impression.  Just like stamping into soft clay.  With more refined techniques in recovering fossils in the field (or prepping them at the museum), paleontologists are finding more “skin stamps” than ever before.

 

Corythosaurus casuarius skeleton, by Barnum Brown, 1916.

A hadrosaur mummy.  Keep in mind that the animal was most likely dead and already decomposing when it was buried.  We can’t know for sure if it had more fat under the skin than showed here or not.  Notice how thick and muscular the tail base is. 🙂

Photo not mine.  If you know who needs credit, please let me know. 🙂

Corythosaurus skin.

Bell, 2012

More hadrosaur skin impressions.  The impressions that look like a honeycomb are actually impressions of what’s underneath the bumps.  Reminds me of bubble wrap. 😛

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Photo courtesy of Black Hills Institute of Geological Research

Triceratops skin impression.  No one knows if those larger osteoderms would look just as they do here, or if larger quills or spikes where attached.  Speaking of quills…

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wikipedia commons

A beautiful fossil of Psittacosaurus (distant, small cousin of Triceratops) at the Senckenberg Museum of Frankfurt.  We can’t be sure about color, but you can see the pattern of darker and lighter scales.  Notice how much muscle this critter has, and those quills!  A one-of-a-kind find.  Remember my post a couple weeks back about how hard it is for an animal to be fossilized?  How much more amazing that we have something like this?

Here’s a closer look at those quills…

high resolution images of Psittacosaurus tail quills, from the paper studying the specimen

The general consensus is that these quills are a feather-like integument. Here’s what we don’t know…

  • If all species of Psittacosaurus had them (there’s 18, all very different from each other), and if they did, how much & where.
  • If any other ceratopsians had them.  Psittacosaurus was part of a line that died out, so it’s rather unlikely that Triceratops & co. had them.

 

Now that we’re on the subject of feathers…just look at this exquisite fossil of archaeopteryx. 🙂 It never gets old…takes my breath away every time I see it.

Photo not mine.  If you know who needs credit, please let me know. 🙂

Archaeopteryx used to be famous for being the “first bird”, now we know that just about every smallish dinosaur (and even some big ones) where wearing similar outfits.  Yes, most carnivorous dinosaurs are known to have feathers, it’s just a question of what kind, and how much. 🙂

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Photo courtesy of Institute of Fossil Paleontology and Paleoanthropology, Beijing

I know that looks like fur, but those are fluffy feathers all over this little sinosauropteryx.  Notice the bands of light and dark color on its tail.

Here are some more birdy feathers on a larger dinosaur.

This is Zhenyu- Zhenya- Zen- Oh forget it.  Let’s just say she’s a cousin of those infamous raptors from Jurassic Park.  She’s about five feet long, so closer to the real turkey-sized Velociraptor.  Fully feathered.  Just look at those glorious wings!

Photo courtesy of Stephen Brusatte

Here’s a close up of those feathers.  Notice the full wing in photo D below.  You can clearly see primary, secondary, and covert feathers, just like what you’d see on a modern bird wing.

But wait, it gets better. 😀

Not quite as pretty, but look at figures A, B, and C below.  The bumps that those arrows are pointing to are called quill knobs, and figure D shows us what that means. 😀

Keep in mind that this fossil came from a critter called Dakotaraptor.  This guy was every bit as big as the ones in Jurassic Park.  And it has wings.

Image from paper studying Dakotaraptor.

A prettier reconstruction of Dakotaraptor’s wing.

Photo courtesy to Robert DePalma.

These and other fossils from even larger dinosaurs such as yutyrannus (T-rex’s Chinese cousin) that also preserve feathers, can give us clues for exactly how diverse and widespread feathers are in the dinosaur family tree.

 

The flying reptiles called pterosaurs, for example.

Picture not mine, if you know who needs credit, please let me know.

With fossils like these we can learn about the structure of the wing, and that these animals also had a fur-like coat of feathery fuzz covering their bodies.  No scaly or naked skin here.

 

So there is a lot we do know, but still so much left in the dark.  With bones, muscles, and a few hints of soft tissue, next time we’ll be heading off into uncharted waters.

 

Quick Question: These fossils are all amazing, but there is still so much we don’t know.  Take a quick look at the lion and tiger above, and then look at the skulls below.  Can you tell which one is which?  Leave your answer in the comments, I’d love to hear from you! 🙂

 

Fleshing out the Bones Series: