Tag Archives: Morrison Formation

Know Your Bones: October 2015

There were only two guesses for last month’s challenge, both correct, but one being more correct. I have a feeling that the reason only two people guessed is because this one was such an easy specimen. So, who won, who was the more correct of the two?

 

Camarasaurus

 

It turned out to be WarK, because the other guesser gave the wrong species name. The critter from last month is Camarasaurus supremus.

 

 photo 2014-01-10111738_zps5a90e232.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Camarasaurus lived during the late Jurassic 155 to 145 million years ago. It ranged across most of North America and is an extremely common dinosaur in the Morrison Formation. Camarasaurus had an average length of 18 meters and weighed up to 18 tons. Remarkably, several complete skeletons of Camarasaurus have been discovered in Wyoming, Colorado, Utah, and New Mexico. Based on their fossil abundance it is assumed that they roamed around North America in large numbers during the late Jurassic and may have had one of the largest populations of sauropods, if not dinosaurs, known thus far.

 

Camarasaurus means “chambered lizard;” it most likely got this name from the hollow bones that make up much of the vertebra or the many fenestrae found on the skull. Camarasaurus had chisels shaped teeth that were 19 cm long. The shape of the teeth and strength of the skull suggest that Camarasaurus specialized in eating coarser plant matter. This is different from other sauropods, thus Camarasaurus most likely inhabited a different environment then its cousins that also lived during this time. Camarasaurus remains are found together in a lot of sites, suggesting that they lived and died in herds.

 

Moving on to this month’s challenge:

 

 photo 2013-10-18105402_zps59c3c2eb.jpg
(Taken at the New Mexico Museum of Natural History and Science)

 

Here we have a terrifying critter, which is appropriate for this month. Thanks for playing and good luck.

Know Your Bones: May 2014

Last month’s challenge was extremely easy, so easy in fact that just an hour after being posted Inferno gave a correct answer. However, and this seems to be a theme for this series, WarK posted an even more correct answer a few hours later.

 

 Stegosaurus stenops

I’m guessing with the latter part of the name. From what pictures I could find online that one looked the closest to the picture posted by the Bone Torturer

 

This is indeed Stegosaurus stenops, a very famous dinosaur.

 

 

(Taken at the New Mexico Museum of Natural History and Science)

 

Stegosaurus ranged across most of western North America during the late Jurassic 150 to 145 million years ago, and one specimen was discovered in Portugal. Stegosaurus is found in the Morrison Formation in North America. Stegosaurus stenops could reach a size of ~7 meters in length, although some species of Stegosaurus could reach lengths of ~9 meters. This sounds impressive, but one has to remember that Stegosaurus would have been dwarfed by the sauropods found at the same time and place.

 

 

(Taken at the New Mexico Museum of Natural History and Science)

 

There are two main branches of dinosaur, ornithischians (“bird” hip) and saurischians (“lizard” hip). Stegosaurus belongs to the ornithischian clade. This means that Stegosaurus possesses a pelvis that superficially resembles a modern bird pelvis. Stegosaurus also belongs to the Thyreophora (armored dinosaur) clade. This clade includes all the dinosaurs that had armored backs and tales. The plates found on the back of Stegosaurus and the spikes on its tale make Stegosaurus one of the easiest dinosaurs to identify. The spikes on its tale were most likely exclusively used as defensive weapons against the predators of its time. However, the plates on the back of Stegosaurus may have been used for thermal regulation as well as defense. The plates show blood vessels ran across their surface. This could have also been used for colorful displays when blood was pumped into them.

 

Moving on to this month’s challenge:

 

(Taken at the New Mexico Museum of Natural History and Science)

 

Good luck.