Other Things at the Quarry: Dinosaur Road Trip With Grace Part 5

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.
-We arrived at the quarry and checked out all of the awesome bones on the quarry face.
-And now....

In the last post, we looked at a bunch of pictures that we took from the second floor viewing platform of the quarry face.  In this post, we have traveled below the viewing platform to the first floor to check out some of the awesome fossils that they had below!  Below is a diagram of the quarry wall that shows where the original discovery of the site was made!

Here we have the skull of a species of Allosaurus called Allosaurus jimmadseni!  I believe that this species has not been officially described, but to be honest, the genus Allosaurus is a bit of a mess, so I'm not really sure what exactly is going on!

The arm of Allosaurus.

The foot bones that were discovered of Allosaurus jimmadseni inside a reconstructed footprint!

The skull of Allosaurus jimmadseni in situ (which means that it still is in the rock).

The skull of Allosaurus!

The reconstructed skeleton of Allosaurus!

This nearly complete juvenile skeleton of Camarasaurus is apparently the most complete sauropod skeleton ever found!

One of the signs at the quarry said that a new species of sauropod, called Abydosaurus, has been discovered in the monument in a different geologic formation called the Cedar Mountain Formation!

Here is the skull of Apatosaurus louisae.

A Camarasaurus tooth on the left and several Diplodocus teeth on the right!

Skin impressions of another sauropod dinosaur called Barosaurus!

One of the tail spikes of Stegosaurus!

One of the plates of Stegosaurus!

Some of the baby Stegosaurus bones discovered in the quarry!

The skull of the small ornithopod Dryosaurus!

Unidentified lizard legs and feet.

A small crocodilian called Hoplosuchus.

A fossil conifer cone.

A fossil conifer branch with shoots!

The fossilized remains of an extinct salamander called Iridotriton!

The fossilized remains of the extinct frog Rhadinosteus!

A fossilized shell belonging to a juvenile Glyptops, a type of turtle!

A lungfish tooth plate from a fish called Ceratodus!

The shell of another extinct turtle called Dinochelys.

A fossil clam.

The fossilized belly scales of the extinct crocodilian Goniopholis.

The fossilized jaw bone of the same extinct crocodile, Goniopholis!

Next time: a few more petroglyphs and the Harper's Corner Drive!

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!