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!

Xiphactinus: The Inception Fossil

If you were to travel back 100 million years from where I live in Colorado, the face of a very, very different planet would emerge.  I suppose emerge isn't necessarily the best word in this context: submerged is more of an adequate description!  You see, unlike the mountains you would see in Colorado today, Late Cretaceous Colorado was even flatter than present-day Kansas....and a whole lot closer to sea level!  Between about 100 and 70 million years ago (MYA), an enormous seaway stretched northwards from the Gulf of Mexico, and southwards from the Arctic.  Within these waters, hundreds, perhaps thousands of animals flourished, many of which we have nothing like today.  Massive sea turtles like Archelon slowly swam through the waters, while the long-necked plesiosaurs cruised around, snapping up fish before they even knew they were there.  While sharks and mosasaurs were probably the most impressive denizens of the seaway, these massive carnivores fed on fish as well.  And the subject of today's post is one of those fish: a 17-foot long beastie called Xiphactinus.

Due to the numerous pictures uploaded to Pinterest by the Best Western Denver Southwest hotel (read more about it HERE), I'm going to be using a lot of pictures from this site!  Make sure you check it out by clicking HERE!  Unless otherwise noted, photo credit for all of the pictures in this post goes to that Pinterest page!

Why did I call Xiphactinus (pronounced zye-FACT-un-us) "The Inception Fossil?"  Well, that's a description that I came up with (don't ever let anyone tell you otherwise!) that has to do with one of the most interesting things about Xiphactinus: numerous specimens of the fish have been found with the remains of other fish in its stomach!  Just as the premise behind Inception is "a dream within a dream," so too are specimens of Xiphactinus sometimes "fish within a fish!"  The specimen below is a thirteen foot Xiphactinus that died with a fish known as Gillicus arcuatus in its stomach!

Unlike sharks, Xiphactinus would have been unable to bite off chunks of flesh from its prey, and instead would have had to swallow its prey whole, which is what makes the Inception Fossils so spectacular!  Some paleontologists propose that this lack of chewing may have been what killed some of these Xiphactinus specimens, and that they actually choked to death on their last meal!  I suppose it's possible, but I don't actually know enough about these specimens to be a very good authority on them!

The next three pictures below are pictures that I took of a specimen that I saw a week or so ago.  Long story short, my friends Isabel and Sam Lippincott and I had gone to a presentation given by paleontologist Dr. Ian Miller about the Snowmastodon Project a few months back, and he was impressed with Sam's paleo drawings when we showed him after the lecture.  He invited us to come on down to the Denver Museum of Nature and Science so that he could show us around behind the scenes, which he very kindly did a few weeks ago!  These are pictures I took of the 80 MY old Mancos Shale specimen of Xiphactinus, which was discovered in 1966 by some kids who had been hunting with their dad near Snowmass in Colorado.  They had stumbled across the rib cage of the animal, and had notified the Denver Museum.  The next summer, the museum excavated the remarkably complete, 13-foot specimen, taking it back to the museum, where it has been stored to this day!

Here are some more cool pictures from the Pinterest page!  This is a diorama of paleontologist Charles Sternberg caught in the act of discovering one of his "Inception fossils!"

And here are another pair of reconstructions of Xiphactinus!

Make sure to check out the Pinterest page of the Best Western Denver Southwest by clicking HERE!

The Story of the Kremmling Ammonite Site and a Painting by Wayne Itano, Guest Blogger

Today, we have a very exciting post for you: a guest post from paleo-enthusiast Wayne Itano!  Here is a bit of background on Mr. Itano:  

Wayne Itano is a physicist at NIST (National Institute of Standards and Technology) in Boulder, CO.  He has a hobby interest in paleontology and is also a curator adjoint at the Natural History Museum of the University of Colorado.

Today, Mr. Itano is going to tell us about the Kremmling Ammonite Site.  Join me in giving him a warm welcome!  Let's get started!

The Kremmling Cretaceous Ammonite Locality lies on BLM (Bureau of Land Management) land to the north of the little town of Kremmling, in Grand County, Colorado.  It was first noticed for the very high concentration of very large ammonites(ammonites are extinct relatives of the modern chambered nautilus and were probably more closely related to octopi and squids).  It has been protected since the 1980s.  It was written up in the book “Cruisin’ the Fossil Freeway” by the paleontologist Kirk Johnson and the artist Ray Troll.

Dr. Kirk Johnson, formerly of the Denver Museum of Nature and Science, is now head of the Smithsonian Museum of Natural History.

Ray Troll is an artist with a special interest in natural history and ancient life.  Here is his painting “Night of the Ammonites” inspired by a visit to the Kremmling Ammonite Locality.

Artist Ray Troll’s picture of the Kremmling area, about 73 million years ago, during the Cretaceous Period, when most of Colorado was beneath the sea.  Picture Credit: Ray Troll

The large disk-shelled creatures are ammonites called Placenticeras.  The ones with narrow, straight, tapered shells are another kind of ammonite, called Baculites. The sharp-toothed swimming reptiles are called mosasaurs.  We have evidence from bite marks on ammonite shells that mosasaurs preyed on Placenticeras.  Over on the left are some strangely shaped small ammonites called Anaklinoceras.

The Kremmling site was featured by Earth Magazine, in a kind of online quiz called “Where on Earth.”  The page with the question and answer is HERE.

If you want to visit the Kremmling site, first pay a visit to the BLM office at 2103 E. Park Avenue, Kremmling.  They can advise you on road conditions.  At times it can be inaccessible, even for 4-wheel drive vehicles. Here is a sign at the site:

Warning sign at the Kremmling Ammonite protected area.  Photo Credit: Wayne Itano

Here is an informational sign.  Collecting is prohibited within the site, but there are nearby areas where collecting is allowed.  Inquire at the BLM office.

Explanatory sign at the Kremmling site.  Photo Credit: Wayne Itano

The area is littered with boulders containing the impressions of giant Placenticeras ammonites.  The fossils themselves have been collected, many to museums.  Intact boulders containing ammonites lie under the surface and could be studied in the future.

Boulders with impressions of Placentideras ammonites.  Photo Credit: Wayne Itano

Baculites (straight ammonites) are also rather common. 

A Placenticeras ammonite impression with a Baculites fossil (cylindrical object) on the same boulder.  Photo Credit: Wayne Itano

Large clams called Inoceramus are rather common.  Here are some examples.

A large Inoceramus clam fossil.  Photo Credit: Wayne Itano

A boulder with impressions of Inoceramus clams.  Photo Credit: Wayne Itano

Emmett Evanoff, a professor at the University of Northern Colorado in Greeley, has been studying the paleontology of this area.  One odd thing is that the great majority of the Placenticeras fossils are of females.  (The males are distinguished by being much smaller and having coarse ribs on their shells.) He thinks this might have been a nesting site.  The males would have fertilized the eggs and then left, leaving the females to guard the eggs.  Katie DeBell was a student of Emmett’s who mapped out the ammonites on the surface and seems to know them all by number.  She lives in Kremmling and often gives tours, especially to school groups.  Here she is, pointing out some features of one of the ammonites.

Katie DeBell explaining some features of an ammonite in 2011.  Photo Credit: Wayne Itano

I have a vacation house in the mountains not far from Kremmling.  I happen to know a painter who is also a fossil enthusiast, named Terry McKee.  I commissioned him to do a painting of the Kremmling site when it was an ammonite nesting ground.  I also asked Dr. Evanoff for advice, and the three of us met to plan the painting.  Here it is, and the original is now hanging in my mountain house.

Painting of the Kremmling Ammonite nesting site.  The large ammonites are guarding their eggs.  Baculites and various smaller ammonites, swim above.  The small round ammonite on the left, facing left, between two of the straight baculites, is a male Placenticeras.  A mosasaur lurks in the background.  Picture Credit: Terry McKee

- Wayne Itano

Thank you very much, Mr. Itano, for the post!  The post was really interesting, and I know I learned a lot!  I found the part about the nesting site particularly interesting!  I have no doubt that my readers, as well as myself, would love to hear from you in the future!  Thanks again! - Zack Neher

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23-Fact Tuesday: All About Allosaurus!

Today we are going to do yet another 23-Fact Tuesday, and this time it is all about a particularly interesting dinosaur known as Allosaurus.  But this 23-Fact Tuesday is particularly special, as it is also the birthday post of one of my personal heroes and one of the people who inspired me to take this dinosaur- and animal-oriented path, Mr. "Dino" George Blasing!  Happy birthday, Mr. Blasing!  Here we go!

Allosaurus Vs. Stegosaurus at the Denver Museum of Nature and Science

1.  On Halloween in 1879, Arthur Lakes discovered a tooth from a dinosaur that was later identified as Allosaurus in Wyoming.

2.  In the United States, Allosaurus is found in the Morrison Formation, and lived alongside other animals such as Stegosaurus, Apatosaurus, Ceratosaurus, Camptosaurus, Gargoyleosaurus, and many others. 

A skeleton of Gargoyleosaurus from the Denver Museum of Nature and Science

Allosaurus Vs. Camptosaurus that I saw at a traveling exhibit at the San Antonio River Walk in Texas

Ceratosaurus at the Smithsonian

Stegosaurus at the Utah Field House

3. The claws on the hand of Allosaurus could reportedly grow up to 10 inches long.

The arm and the claws of Allosaurus, mounted at the Morrison Natural History Museum

4.  Some scientists believe that Allosaurus had a very weak bite, around the strength of a leopard.  Regardless of exactly how weak of a bite it had, Allosaurus was definitely not a heavy-biter champion, and many paleontologists hypothesize that it instead used its skull sort of like a hatchet to kill its prey, using its razor-sharp teeth to critically injure its prey.

5.  The first fossils of Allosaurus that were ever discovered were originally thought to be petrified horse hooves.

6.  Allosaurus is the state dinosaur of Utah.

A reconstructed skeleton of Allosaurus at the Cleveland-Lloyd Dinosaur Quarry in Utah

7.  Allosaurus certainly didn't sit on its rump and enjoy hamburgers and tea, as their skeletons show that they suffered many injuries throughout their lives.  As a matter of fact, the Allosaurus specimen that is on display at the Smithsonian Institution has a number of broken ribs, a smashed shoulder blade, and a damaged lower jaw.

A crushed femur belonging to Allosaurus from the Cleveland-Lloyd Dinosaur Quarry

8.  The lower jaw of the specimen at the Smithsonian was so damaged, in fact, that it took scientists more than 100 years to figure out that it was, in fact, an Allosaurus jaw!

9.  A predator-prey relationship between Allosaurus and Stegosaurus was all but confirmed with the discovery of a specimen of Allosaurus with a hole in one of its tail vertebrae that perfectly matched the shape and size of the thagomizer on the tail of Stegosaurus.

Allosaurus Vs. Stegosaurus at the Denver Museum of Nature and Science

The "thagomizer" of Stegosaurus, mounted at the DMNS.  Check out THIS post to learn about how this particular part of the Stegosaurus got its name!

10.  "Allosaurus" spelled backwards is "Suruasolla," which means absolutely nothing.

11.  The small horns above the eyes of Allosaurus are mostly thought to have been for display, as most scientists believe them to be too weak to withstand much stress resulting from conflict with prey or other Allosaurus.

12.  Allosaurus gives its name to the group Allosauroidea, which includes the Chinese theropods Yangchuanosaurus and Sinraptor, and the carcharodontosaurids, which includes one of the largest carnivorous dinosaurs of all time, Carcharodontosaurus, amongst other dinosaurs.

13.  Some of the other scientific names that Allosaurus fragilis has had over the years are Allosaurus lucaris, Allosaurus ferox, Labrosaurus ferox, Labrosaurus lucaris, Antrodemus, Poicilopleuron valens, Laelaps trihedrodon, Epanterias amplexus, Hypsirhophus discurus, Hypsirhophus partim, and Creosaurus atrox, with a few other names under debate right now.  Specifically, some scientists think that the dinosaur known as Saurophaganax is the same animal as Allosaurus.  However, I have talked with a few people, including Matthew Mossbrucker, curator of the Morrison Natural History Museum, and he says that he has seen the remains of Saurophaganax and believes them to be distinct from Allosaurus. 

A reconstructed skeleton of Saurophaganax that I saw at a traveling exhibit at the San Antonio River Walk in Texas

14.  Besides Saurophaganax, Allosaurus was much larger than the other known theropods from Late Jurassic Morrison, such as Ceratosaurus and Torvosaurus.

A reconstructed skull of Saurophaganax that I saw at a traveling exhibit at the San Antonio River Walk in Texas

15.  We humans actually live closer in time to the famous Tyrannosaurus rex, Triceratops, and other dinosaurs from that time period than they do to Allosaurus!

A Triceratops skull at the Morrison Natural History Museum

16.  Allosaurus fragilis was first named by famous paleontologist Othniel Charles Marsh in 1877.

17.  The scientific name of Allosaurus fragilis translates to "fragile different lizard," named such due to the fact that Marsh believed that the vertebrae of Allosaurus would have been quite weak, and were different  from those of other, previously discovered dinosaurs.  Now we know that vertebrae of this kind were quite common.

18.  One of the most famous specimens of Allosaurus is the approximately 95% complete specimen nicknamed "Big Al."  Estimated to be only a teenager at his TOD, he is about 26 feet long, which probably helps to explain why so many of my dinosaur books list the estimated length of Allosaurus at around 26 feet.

19.  Allosaurus lived during the Late Jurassic Period, around 155.7-150.8 MYA in the United States (Colorado, New Mexico, Utah, Wyoming, Montana, Oklahoma, and South Dakota), Portugal, and possibly the Tendaguru Beds of Tanzania, although many people believe that this is African animal is an entirely different animal from Allosaurus.

20.  Work began at the Cleveland-Lloyd Dinosaur Quarry in 1960, and over 40 individual specimens of Allosaurus have been uncovered there since then.

Unarticulated bones of Allosaurus from the Cleveland-Lloyd Dinosaur Quarry

21.  Due to the vast number of Allosaurus specimens discovered in all different stages of its growth development (especially from Cleveland-Lloyd), paleontologists have been able to estimate that Allosaurus reached full-size at around 15 years of age, and lived to around 22-28 years old.

A whole bunch of Allosaurus leg bones all put next to each other to show the growth of the animal, largely based upon bones found at the Cleveland-Lloyd Dinosaur Quarry, which is where this picture was taken

22.  Fossils of Allosaurus are still being discovered to this day, a fact which I can personally attest to.  Blocks of stone are still being excavated at the Morrison Natural History Museum, and bones of Allosaurus, as well as its teeth, are currently being cleaned. 

23.  Allosaurus is the favorite dinosaur of the famous dinosaur educator, "Dino" George Blasing.

And remember, if you have a birthday coming up, just email me the date at cuyvaldar123946@gmail.com with the date and your favorite animal, and I will do my best to get a post in!  And remember, if you like what you're reading, make sure you LIKE US ON FACEBOOK, follow us (if you have a google or gmail account), or hit the subscribe button off to the right if you don't!

Squirrel Footprints on Our Doorstep!

This morning we woke up to a fresh blanket of snow, the first (real) snow of the year for us!  Naturally this means that I must do all of my first snow traditions, including watching the Battle of Hoth scene from Star Wars Episode V: The Empire Strikes Back, and wearing my Mammoth and Mastodon Madness t-shirt from the Denver Museum of Nature and Science.  Anyways, on my way over to school, I saw a few footprints.  I took a few pictures on my phone so they aren't very good looking, but I believe them to be from the eastern fox squirrel, the type of squirrel that is just so common around here in Boulder, Colorado!  If anyone knows otherwise please let me know, but I am 99.99% sure that this is what we are looking at!  The first two pictures are the ones that I took with my phone.  The first picture has an impression of my right index finger in the snow next to the footprints for scale.  The third picture is a picture that someone else took of some eastern fox squirrel footprints in the snow too!

The Thagomizer of Stegosaurus

Stegosaurus is a very famous dinosaurs, one of the most famous, along with Triceratops and Tyrannosaurus.  All three of these dinosaurs have been found in Colorado; in fact, the first Triceratops bones were actually found in Denver, and Stegosaurus is the state dinosaur of Colorado!  Stegosaurus has also been found in Wyoming and Utah, in the Morrison Formation, as well as in Portugal.  The row of plates along its back make it very interesting looking, as do the spikes on the end of its tail, nicknamed a "thagomizer."  Holes in the vertebrae of a potential predator of Stegosaurus, Allosaurus, fit exactly with the size of one of the spikes on the tail of the Stegosaurus, showing that there was almost certainly a predator-prey relationship between the two, as was previously suspected.  Studies have shown that the tail end of Kentrosaurus, a close relative of Stegosaurus, also with a thagomizer on its tail, could have been brought around to the side of the dinosaur, potentially swatting at enemies trying to attack the Stegosaur from the side.

Finally, discoveries of articulated Stegosaurus skeletons show that the spikes were actually horizontal from the ground, as opposed to held at an angle, as you can see in the outdated and incorrect picture below.

It's an interesting word, though, isn't it: "thagomizer."  It certainly doesn't sound like a very sciency name; in fact, when I first heard it, I immediately thought it sounded like something out of one of my favorite comic strips, Calvin and Hobbes, by Bill Watterson.  Well, if you thought that as well, then you were actually surprisingly close to the mark, as the term did in fact come from a comic strip, another one of my favorites: The Far Side.

The term wasn't used scientifically until the year 1993, at the annual meeting of the Society of Vertebrate Paleontology, by the one-time Curator of Paleontology at the Denver Museum of Nature and Science Ken Carpenter.  The name has been used multiple times since then, in different mediums; books and television shows (including another personal favorite, BBC's Planet Dinosaur), as well as places such as the Smithsonian Institution and Dinosaur National Monument.  Although an informal name, it is popular, and has amusing origins.

Gary Larson created a great number of hilarious The Far Side cartoons covering all sorts of topics.  However, it seems like a large number of them featured animals, or were in some way nature related.  You will undoubtedly see a great many of them in this blog as time goes on, but here are a few other amusing dinosaur ones.

Denver Zoo 7/20/2012

Ok, a little off topic, I know, but please, everyone reading this blog, go see the new Batman movie.  Words fail to describe it.  Now go.

OK, back on topic.  Yesterday, a couple of friends and I visited the Denver Zoo and the Denver Museum of Nature and Science.  While I had already seen their new Toyota Elephant Passage, I did get to see a couple of things that I didn't get to last time, some of them not actually at the Elephant Passage.  Although some of the pictures are not very good at all, I would still like to share a few with you.  One of the most exciting things of the day was the new Amur leopard cub that was born recently.  With only around 30 individuals remaining in the wild, the Amur leopard inhabits the Primorye region of southeastern Russia, and is labeled "Critically Endangered" by the IUCN.  unfortunately, all of my pictures of it were terrible.  I didn't get to see the clouded leopard (JUST LIKE LAST TIME.  DARN), but I did get to see the fishing cat!  Native to Pakistan, India, Nepal, Bangladesh and Sri Lanka, the fishing cat is definitely one of my favorite animals.  So here are some pictures, enjoy! 

Elephant demonstration

Asian elephant catching lemons in its mouth.

The "Endangered" fishing cat.  Unfortunately, I didn't get to see the clouded leopard again, just like last time.  Darn. 

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