Boulder Submerged: Not So Strange 70 Million Years Ago!

Where I live in Boulder, Colorado, we aren't used to having a whole lot of moisture.  For the last few days, however, we have been experiencing record breaking levels of rain: as a matter of fact, the sheer amount of rain that we are being inundated with has resulted in enormous levels of flooding, complete with evacuations, destroyed homes and roads, and unfortunately several deaths.  I am actually writing this Thursday evening after having my very first flood day, and we have a flood day tomorrow, too!  (And now I am finishing the post on Sunday and we are STILL getting rain!)  Despite the fact that all of this water in Boulder is quite unusual, if you were to travel back 70 to 100 million years ago right here in Boulder, water wouldn't be the exception: it would be the norm!

You see, 70 million years ago, there were no Rocky Mountains.  In fact, Colorado was nowhere near a mile high above sea level: it was about three hundred feet below!  Due to the fact that what would one day be Colorado was still located on continental crust, the Western Interior Seaway couldn't be super deep: nevertheless, three hundred feet deep was deep enough to contain an enormous assortment of fun creatures!  We've already met a large number of these creatures throughout different posts in the blog, but let's take another look at these guys, as well as other fun filled creatures of this ancient seaway!

Let's start on the shore: multiple dinosaur trackways throughout the nation (including two that I've been to, Dinosaur Ridge near Morrison and the Heritage Museum of the Texas Hill Country) show that many different dinosaurs roamed the shore of the Western Interior, including large ornithopods and large theropods.  Some of these dinosaurs actually died and were swept out to shore, such as the ankylosaur Niobrarasaurus!

Pyg chilling inside of a cast of one of the large ornithopod footprints from Dinosaur Ridge at the Morrison Natural History Museum

They weren't the only dinosaurs that lived on the shore, though: meet the flightless, cormorant-like bird Hesperornis!  Originally discovered by famous paleontologist Othniel Charles Marsh, Hesperornis grew to around six feet in length, and looks very similar to the Galápagos flightless cormorant via the process of convergent evolution!

Hesperornis probably ate a wide variety of fish, squid, and an interesting group of extinct marine vertebrates called ammonites.  Some ammonites could grow to simply ENORMOUS proportions, such as the one in the top left of the picture below, one from the Heritage Museum of the Texas Hill Country that I mentioned above.  Found all over the country (and, as a matter of fact, the world), one particular ammonite site looks like it might be a nesting site!  To learn more about this ammonite nesting site, click HERE to check out a guest post by paleontologist and physicist Wayne Itano!

Ammonites were by no means the largest creature in the Western Interior, however, and neither was Hesperornis.  As a matter of fact, neither of them were all that close at all!  Hesperornis was relatively close to the bottom of the food chain, a fact that we know conclusively due to the discovery of one particular specimen of an interesting animal called Tylosaurus in South Dakota.  Tylosaurus was a type of animal called a mosasaur, whose closest living relatives today are the monitor lizards (like the Komodo dragon and the Nile monitor).   Contained within the stomach cavity of this particular Tylosaurus specimen were the remains of a fish, a smaller related species of mosasaur, and a Hesperornis!  Platecarpus remains, one of those smaller mosasaurs, are sometimes found within the belly of the Tylosaurus, the belly of the beast!

Paleontologists are always very excited when they think they've found the fossilized remains of a predator with the remains of its prey still inside.  This can help establish a predator/prey relationship between the two creatures, a relationship that might otherwise have simply been theorized.  Fortunately for us paleontologists, multiple critters in the Western Interior Seaway have been discovered with other little critters within their stomach cavity!  One of these, which I have nicknamed "The Inception Fossil," we actually did a whole post about a few months back!  Entitled "Xiphactinus: The Inception Fossil," this post was all about a fish called Xiphactinus and why I called it "The Inception Fossil."  As you might have already guessed from the context, the nickname stems from the "fish within a fish" idea: Xiphactinus is often found with other fish inside of its stomach!  Below, you can see one of these Inception Fossils, where a Xiphactinus died shortly after swallowing a fish called Gillicus.

Xiphactinus and Gillicus were by no means the only fish in the sea!  The other day, my friend Sam Lippincott and I visited the Denver Gem and Mineral Show.  We both purchased several fossils there, and one of my purchases was a small tooth of another Western Interior Cretaceous Seaway (WIKS) fish called Enchodus.  The name of this fish roughly translates to "spear fish," and from the picture below, you can probably see why: this fish was definitely made to catch some other fish!  Fossils attributed to Enchodus have been found on either side of the K/T boundary, meaning that this fish seems to have survived the extinction that killed off the non avian dinosaurs, and many of the marine creatures as well!

It looks to me like this tooth may be one of the large protruding teeth on the upper part of the jaw.

Pyg checks out her new Enchodus tooth from the Denver Gem and Mineral Show!

I got another tooth from another fish that would have inhabited the Western Interior: this tooth belongs to the shark Squalicorax!  When fully grown, Squalicorax was around the size of the living great white shark, and would have prowled the oceans much like sharks do today.  As a matter of fact, sharks have survived relatively unchanged for hundreds of millions of years!

Pyg checks out the other tooth she purchased at the Denver Gem and Mineral Show, a Squalicorax tooth!

Next, we have a funky looking group of reptiles that look like nothing that we have on Earth today!  These are the plesiosaurs, and some of them could grow pretty large!  Remember before how we mentioned that Hesperornis was discovered by a guy named Marsh?  Well, Marsh had a paleontology rival named Cope.  This rivalry got kind of out of hand, and resulted in something that today we call "The Bone Wars."  (To learn more about the Bone Wars from the ridiculously funny "The Oatmeal," make sure to click the link HERE!)  One of the particularly famous instances in this paleontological skirmish was when Marsh's rival, Edward Drinker Cope, reconstructed one of these plesiosaurs.  Called Elasmosaurus, Cope accidentally placed the head of the animal on the tip of the tail instead of in its proper place at the end of the neck.  As you can imagine, Marsh took the opportunity to mock his rival.  This also sets up the perfect joke for The Oatmeal, but I won't spoil it for you: you have to check it out for yourself!

Although there were other plesiosaurs that swam through the ancient North American seas, my favorite is the funky looking Dolichorhynchops!  This type of short-necked plesiosaur has also been found in the stomach of the enormous Tylosaurus!

Dolichorhynchops is most definitely not a familiar face to your average Joe, but what about Archelon?  This massive sea turtle also inhabited the seaway, and is actually the largest sea turtle known to science!  This guy is about 13 feet long, which is about twice as long as the leatherback sea turtle, who are the largest living sea turtles!  And although Archelon looks similar to sea turtles today, it definitely doesn't look like the turtles we have in Boulder!

Just as the floodwaters are subsiding, so too did the Western Interior Seaway drain from the center of the North American continent.  As the Rocky Mountain started getting pushed up and the elevation got higher and higher, the shallow sea got shallower and shallower, until there was nothing left.  Nothing left, that is, except for the fossils that we find today!  And who knows, maybe the floodwaters from the recent storms have eroded away some overburden, revealing some prehistoric marine fossils beneath!

What is a Pterosaur?

Most of you have probably heard about the so-called "pterodactyls," the flying creatures that lived during the time of the dinosaurs. Like most of us, you might not know exactly what a pterodactyl, more properly known as a pterosaur, is. Is it a bird? A bat? A dinosaur? Possibly even an insect? Or a distinct group of archosaurs that are thought to be fairly closely related to both dinosaurs and crocodilians, but scientists still aren't 100% positive how they fit into the reptilian family tree? Well, if you were thinking the last option, then lo and behold: you're right! Although the pterodactyls would have soared through the skies much like birds, bats, and even some insects of today, they would have been a distinct group altogether. They are also not quite dinosaurs: as the last option says, no one knows quite yet how exactly they fit in!

Pyg perches next to the skeleton of one of the most famous pterosaurs, Pteranodon, at the Morrison Natural History Museum in Colorado!  

Another misconception you might be suffering under is what these extinct flying reptiles are actually called. Although most people call them pterodactyls, that isn't quite the correct term for them. Scientifically, these creatures are known as the pterosaurs. The name pterodactyls actually originates from a small pterosaur that is commonly found in the fine-grained Solnhofen fossil beds in Germany. Known as Pterodactylus, several hundred of these little reptiles have been discovered!

Pyg checks out a cast of one of the more famous Pterodactylus specimens from Solnhofen!

The Solnhofen quarries are world renknowed for their excellent fossils. Not only have a large number of Pterodactylus specimens been uncovered there, but it was from these quarries that the very first Archaeopteryx was uncovered in 1861.  This primitive bird is one of the missing links between birds and dinosaurs, as it shares many features in common with both groups (such as feathers with birds and hand claws and teeth with dinosaurs). Other famous and important animals to come out of the Solnhofen Quarries include numerous crustaceans, insects, and even a small crocodile called Alligatorellus!

Pyg learns more about both the Pterodactylus specimen from above (left), but also about Archaeopteryx (right)!  This cast is of the best specimen of this primitive bird, and was discovered in 1877!  (The original specimen was, not the cast).

Part of the reason why the Solnhofen Quarry is so darn special is the extremely fine-detail preserved in the fossils. As I just mentioned in the previous paragraph, feathers have been discovered with Archaeopteryx specimens. Feathers, much like skin, hair, and other soft-tissues, rarely fossilize. As the science of paleontology slowly evolves, just like the animals it studies, paleontologists become better and better equipped to deal with, not to mention find, these soft-tissue elements of these extinct animals. More and more dinosaurs are being discovered with not only skin, but oftentimes feathers, such as Microraptor, an animal fairly closely related to Velociraptor of Jurassic Park fame; Dilong, an ancient ancestor of Tyrannosaurus rex; and the bizarre therizinosaurs; amongst many others.

And it's not just feathers that fossilize, either. Wing membranes, composed of a flap of skin, are being discovered more and more frequently when it comes to pterosaurs. When it comes to Pterodactylus, scientists have such a large sample size that they are able to reconstruct much of the soft-tissue anatomy of this particular pterosaur! Scientists also have a very thorough growth series for this particular pterosaur, with individuals ranging from hatchlings, just a few days to a few weeks old, all the way to very old individuals with wingspans of around five feet, which, for a Pterodactylus, is very hefty indeed!

Although we've talked a lot about Pterodactylus, there are many other fascinating pterosaurs! I've taken a recent interest in pterosaurs, but before we dive on in to a wide variety of posts, I wanted to provide a brief introduction! Remember, this is a VERY brief introduction. For a more thorough introduction to pterosaurs, consult a book or something, or check back in the future as we learn more about pterosaurs! Don't hold me to it, but I feel like sometime in the near future, I will be talking about Dimorphodon and the anurognathids! Check back soon!

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Drive to Dinosaur: Dinosaur Road Trip With Grace Part 1

Last Sunday, my girlfriend Grace Albers and I drove down for a few nights to Dinosaur National Monument in north western Colorado and north eastern Utah!  We saw a TON of awesome things, and I am going to share it all with you over the course of numerous posts!  First off, here are some pictures from our drive down there!

First off, we nabbed a few pics of my cat, Chimney, and dog, Daisy, before we left!

Pyg stops for a rest break at Lake Dillon near Frisco and Silverthorne!

Some pretty scenery on the road again!

A nice lunch of home made pasta salad, thank you mother!

Around Rifle I believe, Grace spotted a bald eagle!  We were moving pretty fast (but not over the speed limit, of course), so we didn't get any good pictures, but it's still enough to tell that it's a bald eagle!

A bit after the bald eagle, we saw some pronghorn, one of my most favorite animals of all time!  We will be talking about the evolution of the pronghorns speed sometime within the next few weeks!

After the pronghorn stopped to look at us in the picture above, the pair took off, and we got some great action shots!

We kept driving, and got some more awesome shots of the surrounding landscape!

It wasn't too long before we saw our second group of pronghorn, this one much larger!  Pyg tried to spot them, but you really need a zoomed in picture to see them.  Actual eyes and a brain don't hurt, either.

Here are some closer pictures of the pronghorn!  Below is a picture of a female.

Next, we have several shots of several pronghorn, with the male being the individual on the far right (or the only individual in the shot).  While female pronghorn have horns just like the males, they are much smaller, and are rarely pronged.

This looks like a female and a calf grazing!

Several shots of the sagebrush shrublands: Grace really enjoyed the landscape, as did I!

Finally, we were getting close to Dinosaur National Monument!  We first reached the Canyon Visitor Center, which is situated right next to the beginning of the Harper's Corner scenic drive, which we will most definitely talk about later on!  While we were at the visitor center, Pyg desperately wanted her picture taken next to this pre-rennaisance, old school Allosaurus model!

Utah, at last!  More state signs need to have dinosaurs on them, in my opinion.

Some more landscape shots!

We reached the small town of Jensen, and then turned north on the final leg of our journey!  Right after the right turn however, we spotted some funky looking deer, and went back a little ways to check it out!  On someones private property was a group of several fallow deer, a species of deer that, although it has its origins in Europe and Asia, has been introduced on every continent except for Antarctica!  There were several small and cute fawns in the mix, as well!  Notice that all of the deer, regardless of age, are spotted.  Unlike the mule and white-tailed deer fawns that live here in Colorado, the adults do not grow out of their white spots, and instead keep them their entire lives!  We actually saw several of these critters at the drive through animal park near my Gramma Roo's house in Texas, click HERE to check out that post, too!

At last, we reached the national park!

We stopped just inside the park to consult the map, and to check out the Green River!  While our side of the river was National Park, the boundary of the park traced the rivers course for aways, as you can see in the picture of the map below.  Right on the other side of the river was actually cultivated farmland, whose green pastures was a stark contrast to the arid sagebrush shrubland and desert right on the other side of the river.  I wonder just how much water they use to keep all those plants green?  We will actually talk more about water related issues in future posts of this series, including a fascinating fact that I learned about a dam!  But that comes later....

There were several Canada geese on one of the sandbars.  It was weird for me to see them out here in the middle of nowhere: usually when I see them, they are pooping all over the green grasses of the schools near my house!

The scenery in the park is pretty spectacular, and here are just a few shots of some of the rocky outcrops that we saw right away!

We finally got to our campground, the Green River Campground (consult the map above), which, as you might have already guessed, is a campground right along the banks of the Green River.  (If you didn't get that one, don't worry about it, it was supposed to be a tough one, most people don't get it the first time, either.)  Here is a shot of some more gorgeous outcrops between the trunks of two cottonwood trees at our campsite, followed by a picture of our tent!

Immediately upon arrival, we were plagued by several golden mantled ground squirrels who were positively itching for food scraps from us humans.

After we'd settled in, we decided to walk down to the river for a few minutes.  It was really gorgeous there, and we saw a ton of what I think are frog eggs in the water!

It was getting late in the day, but before the sun set, we wanted to go exploring.  Grace is super into Archaeology (Grace:Archaeology::Zack:Paleontology), so we decided to go check out: some petroglyphs.

Join us for our next installment, coming shortly: In Which We Check Out Some Petroglyphs!