Stegosaurus Neck Armor Plate

[killer2906]

Hello,

is this a real Stegosaurus Neck Armor Plate?

The seller say it com from the Morrison Formation and is 150 million years old.

Thank you and best regards.

Michael

[Troodon]

I asked myself the same question when I saw it this morning. It has the general shape of a neck plate but never paid attention to one to really know. It's a very worn and beat up but I like that it's thicker at the bottom and tapers down. There is a lot of glue on it because of its poor condition. What concerns me and it may be because of condition is price. Most plates I've seen sell for a lot more. The other oddity is locality most of the Jurassic material sold comes from wyoming, Utah or Colorado but Montana has jurassic exposures. I cannot positively confirm it but would not dismiss it.

[Troodon]

Let me continue. I have a pristine plate from around the sacrum (much wider) and took a look at it. I also had a very old reference book that showed a plate but I'm not sure of position. Whats evident is that the top of these plates become very thin and the connecting point is not like the specimen for sale. So this brings to question on the authenticity of the specimen. Neck specimens may be different.

Edited February 18, 2016 by Troodon

[Troodon]

Found my 1914 copy of Charles Gilmores Osteology of Stego's and in it a great picture of plate 1, 2 & 3. The rectangular ovalish shape appears to be different than the one offered for sale. Plate 3 also looks feathery thin on the distal end. Still not a conclusive match but it just may be a badly preserved specimen

[killer2906]

Thank you very much Troodon

Yeah it is very hard to tell that it is a Stegosaurus Plate.

[Ridgehiker]

We often get photos of some dinosaur element and asked for ID.

Most identification is done by holding the specimen in the hand. You get to know the feel, texture, subtle shape, etc. Is it theropod or herbivore? Ankylosaur or hadrosaur? Is a flat piece scapula or pelvis?

Also, a lot of this is elimination. We know what it is 'not'. It's not ceratopsian frill...it's not skull material...it's not part of a vertebra, etc.

The same applies to a locale or formation. Most experienced fossil hunters know right off if a piece is from a particular site or age. They could pick up the specimen above and know immediately if it was Jurassic and thus 'possibly' stegosaurus or whatever.

Anyways, unless someone has handled a few Stegosaurus armour plates and knows the material then not really possible to confirm an ID beyond some general 'could be but...'. Part of the fun of paleontology is it a mystery.

Also, to pile on the caution...there are lots of errors in older publications. It's easy to say a fossil looks like one in a photo but the one in be photo was misidentified. This is especially he case with early works on Alberta fossils. Dino elements were found together and assumed to be from the same species but they weren't. They were mixed together. Then in addition, articulated Dino's are rare...so did the person labelling the specimen have access to an articulated Dino to know where the specimen fit in? Was the bone in the drawing of an articulated Dino actually found or was it filled in to complete the illustration?

Edited February 19, 2016 by Ridgehiker

[charkee]

I also am curious about the stego's plates. For example does the texture and thickness of the plate vary throughout the development of its life? Were there multiple kinds of stegosauruses alive on the planet at the same time? Look like they're from three different kinds of animals three or four and I find an anchorio source right right there with it I'm curious or how I mean how could this be?  was there any kind of Ankhlyasauras alive on the planet with Stegosaurus? Also I'm curious to stegosaurus running herds or small families?

 

[Troodon]

3 hours ago, charkee said:

I also am curious about the stego's plates. For example does the texture and thickness of the plate vary throughout the development of its life? Were there multiple kinds of stegosauruses alive on the planet at the same time? Look like they're from three different kinds of animals three or four and I find an anchorio source right right there with it I'm curious or how I mean how could this be?  was there any kind of Ankhlyasauras alive on the planet with Stegosaurus? Also I'm curious to stegosaurus running herds or small families?

 

 

Stegosaurus is part of the family of Stegosauridae that lived in the late Jurassic and early Cretaceous and fossils have been found all over the world.  Have not counted them but you're looking probably over 15 genus/species and new ones continue to be discovered. They all look a bit different as to the type of plates and spikes they have.   I've attached a link with more information.  

 

https://godzilla-and-friends.fandom.com/wiki/Stegosaurs

 

The Morrison Formation in our west has about five different genus/species all have different plates.  The illustration below shows four.

 

There is a paper that examines the ontogenetic changes of the plates and spikes which is attached.  It states :

"The plates and spikes we examined show different timing of development of structural features seen in old adults. While plates acquire pipe-like large canals in the young adult, spikes acquire a thick cortex with a large axial channel in old adults. These results may suggest that the acquisition timing for the respective functions of the plates and spikes might be different."

 

https://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2011.01122.x

 

 

On the family groups or herds not sure we really know since we don't have enough fossil evidence.   In Colorado there is a trackway of adult and small Stegosaur's moving in the same direction so there probably was some parental care.   From what I've read it's doubtful they were in the large herds that you see in the late Cretaceous.  So possibly small groups or herds.

 

Your final question on Ankylosaurs being present and yes they were.  Check out this bad boy from the Morrison Formation.  Others existed.

Gargoyleosaurus parkpinorum