Drive to the Quarry: Dinosaur Road Trip With Grace Part 3

PREVIOUSLY, ON BATTLESTAR GALACTICA:

-Grace Albers and I are taking a trip down to Dinosaur National Monument in Utah and Colorado.
-We checked out some cool petroglyphs and then camped the night.
-And now....

Grace was up before I was, and got some cool pictures near the Green River that went right by our campsite!

A sprinkler going off on the farmlands across the river!

A golden-mantled ground squirrel back at the campsite!  These things sure can get pesky, especially if there's food around!

After a quick breakfast, we were off to the quarry!  Here are some of the gorgeous scenery shots on the way!  Pyg definitely enjoyed our view of the Green River!

The Green River in the bottom of the shot!

And then....we saw it!  As we were driving, Grace suddenly told me to stop and back up (as there was no one on the road.  I was being safe, mother, don't worry).  Her instincts were right: it was a golden eagle!  Here are a ton of great shots she took!

Pretty awesome pictures, right!  Well, we continued on to the quarry and were met with an enormous Stegosaurus statue out front!  Here is a picture of Grace next to it!

And here's a Pyg pic!

We went inside of the visitors center.  While we waited for the shuttle to arrive to take us up to the quarry, we looked at some of the things that were inside of the visitor center!  First off, we have some fossil lizard footprints from the Chinle Formation, a Late Triassic formation of North America, whose rocks are around 225 million years old!

Next we have part of the jaw of the large Morrison Formation predator Allosaurus!

Now THIS I thought was really cool, and we will talk more about it in later Dinosaur National Monument posts, but pretty much the two pictures below are before and after pictures.  The first picture is what the intersection of the Green and Yampa Rivers looks like today.  The second is a drawing of what the area WOULD look like if a dam had been built downstream in 1950!  Fortunately, the dam plans were averted!  We will talk more about this dam thingy later!

Pyg touches a large hunk of rock that is about 1.2 BILLION years old!

"What do they keep in there, King Kong?"  Nice Jurassic Park reference, Zack.

After a bit of waiting, the shuttle arrived!  Pyg eagerly awaits our departure!

As we were boarding the tram, I noticed a pair of birds of prey soaring above our heads!  Originally, I thought that they were two of the same birds, and it wasn't until after I put the pictures onto my computer that I realized that these were two very different birds, indeed!  However, I had little to no idea what these birds were, so I contacted Anne Price, the Curator of Raptors at the Raptor Education Foundation, who often brings some fantastic birds to the Best Western Denver Southwest!  To see some fantastic pictures of these experiences and to learn more about them, click HERE and HERE!

Anyways, after talking with Anne, she said that the above picture, as well as the two below, are all of an immature red-tailed hawk, "with a very distinct “dash-and-comma” markings on the wings."

Anne got pretty excited about this last picture, though!  Here is what she said in the email:

"I am 99% certain it is an adult goshawk!!  Very rare to see this bird soaring, and totally in an unusual area; this bird is getting ready  to migrate, or has already started to. Of the 3 accipiters in the US (which are known for having short wings and long tails), the goshawk has the longest wings proportionally to the body and tail. You can very much see that in evidence in your photo. The distinct stripes on the tail are a giveaway too."

Pretty exciting stuff, I'm glad we got the chance to see one!

Finally, as the tram started moving, we noticed some ripple marks frozen in the rock face above us, a reminder that most of the surrounding area was under a shallow inland sea!

Next time: The Quarry!

Meet Marshosaurus, Morrison's Mysterious Meat Muncher!

If I were to tell you to picture the environment of the Morrison Formation 150 million years ago (MYA) in the Late Jurassic Period, most of you would probably have no idea what I was talking about.  For some of you, the words “Morrison” and “Late Jurassic” would trigger images of enormous sauropods like Apatosaurus and Diplodocus, with the occasional plated Stegosaurus, and the carnivorous Allosaurus.  For still fewer, images of the ornithopods Camptosaurus and Dryosaurus might appear, the theropods Ceratosaurus and the smaller Ornitholestes, and perhaps another sauropod or two.  Fewer still might picture the theropod Torvosaurus, the ankylosaur Gargoyleosaurus, and the ornithopod Othnielia.  However, very few people indeed would think of the medium sized, 20-foot long theropod Marshosaurus.

Marshosaurus bicentesimus was first named in 1976, and received the second half of its scientific binomial name (bicentesimus) from the fact that it was described during the bicentennial of the United States!  The first part of the name (Marshosaurus) honors the famous paleontologist Othniel Charles Marsh, one of two main participants in the extreme paleontological competition more than 100 years ago!  If you want to learn more about the Bone Wars, be sure to check out a song that I wrote about it below: to the tune of Carrie Underwood's "Two Black Cadillacs!"

Anyways, all silliness aside, I actually got to see what is widely considered to be the most complete Marshosaurus specimen ever discovered about a month back when my friend Sam Lippincott and I got to go on a behind the scenes tour of the Denver Museum of Nature and Science with paleontologist Dr. Ian Miller!  To be honest, even from a paleontologists perspective, the Marshosaurus specimen was definitely not the most exciting thing there, not by a long shot!  Overall, all of the known material attributed to Marshosaurus taken together, there sure isn't much: four fragmentary skeletons, composed of bits and pieces of the spine, skull, and pelvis.

One of two small trays of bones belonging to Marshosaurus that the Denver Museum has on display in the paleo lab for the time being.  Looks like we have some vertebrae and ribs!

One of two small trays of bones belonging to Marshosaurus that the Denver Museum has on display in the paleo lab for the time being.  This box contains the right maxilla of the specimen.  You actually have a right maxilla, too: just tap abut halfway between your nose and your mouth on the right side of your face: that's your right maxilla!

According to a brief article written by paleontologist Dr. Joe Sertich and published in the Denver Museum's magazine, the specimen of Marshosaurus held at the Denver Museum has "large portions of the skull....several vertebrae, bones from the back and neck, and ribs."  Although it doesn't give us a lot to work with, such fragmentary remains are often all that paleontologists have to work with!  It appears to have been enough for some scientists to come to the conclusion that Marshosaurus is a member of the megalosauroids, a distinct group of meat-eating theropod dinosaurs that includes the famous Megalosaurus, the very first dinosaur ever described!  (I would say discovered, but most people suspect that ancient races have been discovering dinosaur bones for hundreds of thousands of years: but more on that later!)  It is thought that Spinosaurus and its relatives are closely related to the megalosauroids as a group.

According to the article, the remains of the Denver Museum's Marshosaurus specimen were discovered at a site in Dinosaur National Monument that, due to a fluke of the law (I would say loophole, but I feel like that's too harsh of a word), allows the Denver Museum to collect fossils and take them back to their collections, as opposed to them going to the collections facility at the visitor's center.  At this particular site, the remains of "at least six other animals made their way back to Denver."  Amongst these remains  includes the small, plant-eating ornithopod Dryosaurus, and the very famous Stegosaurus, as well as a few bits and pieces of a crocodile!

So how likely is it that Marshosaurus will become as famous as Tyrannosaurus and Triceratops?  Not very likely at all!  But it's a cool animal, and I definitely hope we find the remains of more of these guys sometime in the future!

The Morrison Biota

Stegosaurus lived in western North America during the Late Jurassic Period, about 150 million years ago (MYA). Today, we find its remains in the Morrison Formation, named after the tiny town of Morrison in Colorado. What was going on in Colorado at that time? What was the depositional environment like, the environment that laid down the sediment that would one day become the famed Morrison Formation?

Well, according to paleontologist Dr. Robert Bakker in an article about the re-discovery in 2002 of some old paleontological quarries (CLICK HERE TO LEARN MORE) in the Smithsonian Magazine, the environment was very much like the kind of environment seen in Uganda today: a “hot tropical woodland that was dry for most of the year.”

What about the animals, though? Dr. Bakker also said in the article that to “understand the Late Jurassic, you need to understand the common animals, which means Apatosaurus.” Most people are familiar with this massive animal: about 100 feet long (around the length of three school buses put end to end to end), and weighing around as much as eight African elephants, Apatosaurus was definitely a heavyweight of the Morrison biota!

What other animals were running around though? There are a great many dinosaurs, as well as many other animals, that were living in this area at that time, but in this post we are only going to look at one more: Camptosaurus and Allosaurus. All right, I lied. We’ll look at two more.

First off, we have Camptosaurus. To be honest, Camptosaurus doesn’t really look all that special. A small- to mid-sized ornithopod, Camptosaurus was only about fifteen feet long, and didn’t really appear to have any obvious defenses. However, discoveries of articulated Camptosaurus skeletons (indicating that the bones were fossilized were they were deposited, i.e. where the animal died, and weren’t washed together in a big mumble-jumble like at Dinosaur National Monument) in close conjunction with articulated Stegosaurus skeletons seems to indicate that these two herbivores liked to hang out together. But why? Why would they open themselves up to competition and potential conflict like that? Well, analysis of the brains and skulls of these two animals suggests that perhaps by hanging out together, the dinosaurian duo could avoid much deadlier conflict. Studies have shown that the sensory organs of Camptosaurus and Stegosaurus would have differed in very critical ways. The sense of Stegosaurus would have been akin to a rhinoceros, or perhaps myself as well (at least without my contacts), in that it would have had a pretty good sense of smell, but not very good vision. Camptosaurus, on the other hand, appears to have had quite acute vision, which has led to an interesting proposition by researchers: that Camptosaurus acted as a lookout for herds of Camptosaurus and Stegosaurus. If a predator was spotted (say, an Allosaurus or a Ceratosaurus), then Camptosaurus would have been able to alert the herd, and Stegosaurus would have been able to move to the forefront to defend them all against attack.

The last dinosaur that we are going to look at today is Allosaurus, a large, meat-eating theropod dinosaur. It occurs to me as I type this that I have done a very thorough job on Allosaurus before, so instead of typing this all again, I am going to be lazy and redirect you to another post that I did awhile back, entitled “23-Fact Tueday: Allosaurus.” Hidden within the post (but not too hard to find) are 23 Facts about Allosaurus. Yeah. Pretty much says it in the title. Anyways, check out that post to learn more about Allosaurus, as well as the rest of the Morrison ecosystem! And make sure to check back tomorrow, as we learn about stegosaurs from the rest of the world!

Want to learn more about Stegosaurus?  Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities!  

Baby Stegos Galore (Stegosaurus Week)

In 2002, paleontologists from the Morrison Natural History Museum rediscovered an old paleontological dig site that had been missing since the late 1800s. One of many highly-contested sites of the so-called “Bone Wars” (a paleontological competition between rival paleontologists Othniel Charles Marsh and Edward Drinker Cope), this dig site, dubbed Quarry 10, has been the site of many very interesting discoveries, as has another Quarry nearby, Quarry 5.

Quarry 10 had long thought to have been destroyed. Fossil hunter Arthur Lakes had reportedly dynamited the dig site on Marsh’s orders, to prevent Cope from getting any fossil bones out of it. However, it looks like Arthur Lakes was a very good man, and did not actually dynamite the dig site. According to the MNHM paleontologists, it looks like Lakes, not wanting to destroy something that was potentially very valuable, decided to merely cover up the site with some rocks in order to prevent other people from coming across it.

Further excavations at the Quarrys have yielded a number of VERY interesting fossils, including, amongst others, some baby Stegosaurus footprints! Multiple blocks have been uncovered with the footprints of Stegosaurus at all different stages of development, everything from infants to adults. On some of the blocks, multiple age groups are found in close conjunction to each other, and sometimes are found going the same way. This seems to indicate that Stegosaurus would move in groups consisting on members of multiple ages, a very interesting discovery indeed!

Want to learn more about Stegosaurus?  Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities! You can also check out a song that I wrote to the tune of Carrie Underwood's "Two Black Cadillacs" to learn more about the Bone Wars, below!

The Thagomizer of Stegosaurus (Stegosaurus Week)

This Saturday at the Morrison Natural History Museum in Morrison, Colorado, we will be celebrating Stegosaurus Day, in honor of Colorado's state fossil!  (To learn more, click HERE to be redirected to the Facebook page of the Morrison Natural History Museum!)  So, in honor of Stegosaurus Day, The Natural World is going to have ourselves a little Stegosaurus Week!  Each day, we are going to be looking at a different aspect of Stegosaurus, and today, we are going to be looking at the tail spikes on the tail of Stegosaurus, nicknamed the thagomizer!  What were they used for?  Did they actually use their tail spikes for defense?  And how about that funky name: where did the term "thagomizer" come from?  Well, learn those answers and more in today's post for Stegosaurus Week!

Remember IN THE LAST POST OF STEGOSAURUS WEEK when we mentioned paleontologist Ken Carpenter and his very complete and articulated Stegosaurus skeleton?  Well, in 1993, when Carpenter was presenting his findings, he first used the term "thagomizer" to describe the tail and spikes of Stegosaurus.  Without even knowing its backstory, it seems like a fitting name: but its true origin is even more interesting!  For those of you who have enjoyed Gary Larson's fantastic "The Far Side" comic strip, then you may already know where we are heading with this!  One of my favorite "Far Side" strips is the one above, and, interestingly, it is from this strip that Ken Carpenter got the name "thagomizer!"

Now, one question that has stumped paleontologists for years is, how were the spikes arranged on the thagomizer?  Nowadays, we know that there were two sets of spikes, and they are thought to have been about 180 degrees from each other, forming a horizontal line.  (For a more complete discussion, see the last post in our Stegosaurus Week series, entitled THE GENUS STEGOSAURUS THROUGH TIME.)  But other questions stumped paleontologists, too.  For example: what was the thagomizer used for?  It definitely looks like a very apt defensive weapon, but for a long time, paleontologists had no clues to help them figure out whether defense was actually the answer.

One source of evidence that Stegosaurus and other stegosaurs were using their thagomizers to defend themselves is that many of the spikes have broken tips.  Now, just because a fossil is broken, doesn't necessarily mean that it was broken during the animals life.  Paleontologists can tell whether or not a bone was broken during the life of the animal by looking to see whether the bone shows any signs of healing.  If the fossilized bone shows signs of "remodeling," then the bone broke during the life of the animal, and then started to heal while the animal was still alive.  Following the death of an animal, if somehow a bone becomes broken, it's not going to heal: the animal is already dead!  In a study that examined 51 tail spikes of Stegosaurus, researchers found that about 10% of these spikes had broken tips whose bone had started to grow back.  So clearly, these spikes weren't just for show, and were actually being used for something.

The best evidence that paleontologists have right now that indicates that Stegosaurus was using its thagomizer to defend itself against predators is an Allosaurus tail vertebrae with a hole in it: a hole exactly matching the kind of hole that a thagomizer would have made!  What's very interesting about this fossil is that, while damaged bone in the vicinity of the hole shows signs of healing (indicating that the Allosaurus survived, at least for a little while, following its encounter with Stegosaurus, and that the damage to the vertebrae was not post-mortem), the hole itself doesn't seem to have healed at all.  This has caused some paleontologists to hypothesize that part of the tough outer sheath that would have surrounded the tail spikes in life, probably making them sharper and pointier, of a Stegosaurus became stuck in the tail vertebrae, remaining lodged within the tail vertebrae of that particular Allosaurus, until the animal died!

Another picture that I took at the Denver Museum of Nature and Science of an Allosaurus attacking a Stegosaurus adult and juvenile

Want to learn more about Stegosaurus and it's relatives? Well, check out the Homebase for Stegosaurus Week HERE to partake in more of the festivities!

The Denver Gem and Mineral Show Part 6: Dinosaurs and Their Ancient Relatives

At last: here we go on the sixth post of our Denver Gem and Mineral Show series!  Even though I went with my friend Masaki Kleinkopf a few months ago, I still have a large number of picture that I am eager to share with you.  If you are interested in reading about the other posts in this series, feel free to check out the Homebase for the series HERE, with links to all of the other posts in the series that have been created thus far!  Today we will be looking at the dinosaurs, as well as an ancient relative!  Fasten your seat belts, everyone!

Here we have the skull of Allosaurus!  We have discussed Allosaurus extensively, especially in our 23-Fact Tuesday post, so click HERE to learn more about this fascinating creature!

A dinosaur who needs no introduction, but, as you can see, I am introducing him anyways: Tyrannosaurus rex!  I believe the second picture is of the foot of Tyrannosaurus, but I am not one hundred percent positive.

Psittacosaurus, one of the most primitive ceratopsian dinosaurs known to science.  It doesn't even have a frill or horns!  So how do we know that it is a ceratopsian dinosaur?  It has an extra bone on its upper jaw called the rostral.  It is this bone that distinguishes the ceratopsians from the other groups of dinosaurs.

Another dinosaur foot, this one belonging to Diplodocus, a large sauropod from the Late Jurassic Period, whose remains are found in the Morrison Formation. 

 Some fossil footprints that I am guessing belong to a theropod dinosaur, but I don't actually know.

Some fossil bones of a hadrosaur known as Edmontosaurus.  Here is what the card says: "Edmontosaurus sp.  Cervical vertebrae and bone.  Lance Formation.  Maastrichtian.  Late Cretaceous.  Niobrara County, Wyoming."

Some teeth belonging to the massive carnivorous dinosaur Carcharodontosaurus.  Up at the top of the picture, you can see a few from Spinosaurus, as well. 

Various teeth and claws from the Rocky Mountain Dinosaur Resource Center (RMDRC) booth.

This last guy, Desmatosuchus, is not actually a dinosaur, but a type of archosaur.  Although it looks quite fierce, Desmatosuchus belongs to an order of Late Triassic herbivores called the aetosaurs.  Desmatosuchus in particular has been found in Texas, and was around 15 or 16 feet in length. 

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