Ever Wonder Which Morrison Dinosaurs were most Abundant?

[Troodon]

Ever wonder which Jurassic dinosaurs in the Morrison Formation were most abundant? Well at least those collected.

Dr Susie Maidment posted this on twitter

"Hey Morrison Formation fans! Ever wondered what the most abundant dinosaurs in the formation were, based on PBDB data? I did, and I plotted it"

 

Looks like the winners were, no surprise  

Sauropod: Camarasaurus

Theropod: Allosaurus

Ornithischians:  Stegosaurs

 

[jpc]

nice work, Susie.  thanks for sharing, troodon.  

This is also simply a great list of all the Morrison dinosaurs as seen by someone who actively works with them.  

 

 

[Troodon]

25 minutes ago, jpc said:

nice work, Susie.  thanks for sharing, troodon.  

This is also simply a great list of all the Morrison dinosaurs as seen by someone who actively works with them.  

 

 

 

Yea great assemblage however not seeing Koparion on that list must not be in the Database.  Need to keep an eye out for those Troodontids

[Flx]

Thank you for sharing.

When I ID my sauropod stuff it always turns out to be either Camarasaurus or Apatosaurus (or not possible to identify). Theropod material is usually Allo. So this all makes sense statistically. 

 

Is there also an estimate for the ratio between sauropods : theropods : Ornithischians?

[Troodon]

4 hours ago, Flx said:

Thank you for sharing.

When I ID my sauropod stuff it always turns out to be either Camarasaurus or Apatosaurus (or not possible to identify). Theropod material is usually Allo. So this all makes sense statistically. 

 

Is there also an estimate for the ratio between sauropods : theropods : Ornithischians?

 

No that is all that was presented bet you it exists if you were able to go this far.

[Pliosaur]

Seeing that there are so many stegosaurus in the Morrison Formation, makes me wonder why it's rather difficult to find stegosaurus material compared to the others? 

[Troodon]

11 hours ago, Flx said:

Is there also an estimate for the ratio between sauropods : theropods : Ornithischians?

 

Update : when asked she indicated it was done a while back with old data will do it again with new data...stay tuned

[Troodon]

6 hours ago, Pliosaur said:

Seeing that there are so many stegosaurus in the Morrison Formation, makes me wonder why it's rather difficult to find stegosaurus material compared to the others? 

 

Not sure I understand your question...

[Flx]

21 minutes ago, Troodon said:

Update : when asked she indicated it was done a while back with old data will do it again with new data...stay tuned

 

Awesome. Looking forward to this.

[Pliosaur]

@Troodon should have been worded: if there’s such an abundance of stegosaurus , why are stegosaurus fossils rare?

[jpc]

1 hour ago, Pliosaur said:

@Troodon should have been worded: if there’s such an abundance of stegosaurus , why are stegosaurus fossils rare?

My personal experience in the Morrison is that Camptosaurus is more common than stegosaur.  But that is based on a very small sample... we have found one camptosaurus and zero stegosaurs.  : )  

[Troodon]

2 hours ago, Pliosaur said:

@Troodon should have been worded: if there’s such an abundance of stegosaurus , why are stegosaurus fossils rare?

Agree with jpc that was a surprise but whats in the data base she used.  My collection is skewed Campto well over Stego

[Fossil Collect]

On 1/26/2023 at 5:54 AM, Troodon said:

Ever wonder which Jurassic dinosaurs in the Morrison Formation were most abundant? Well at least those collected.

Dr Susie Maidment posted this on twitter

"Hey Morrison Formation fans! Ever wondered what the most abundant dinosaurs in the formation were, based on PBDB data? I did, and I plotted it"

 

Looks like the winners were, no surprise  

Sauropod: Camarasaurus

Theropod: Allosaurus

Ornithischians:  Stegosaurs

 

Stegosaurus? Really I rarely see there fossils available especially teeth!

[Meatasaurus93]

It seems ornithischian material in general from The Morrison tends to be rarer than the other two groups, at least when it comes to the fossil market. Over the past decade+, I've seen far more Morrison sauropod and theropod material for sale than ornithischian.

 

Perhaps the perception of Stegosaurus material being rarer than Camptosaurus is that more people are willing to part ways with Camptosaurus material than Stegosaurus?

[Troodon]

6 hours ago, Fossil Collect said:

Stegosaurus? Really I rarely see there fossils available especially teeth!

 

If you rely on just what you are seeing online not a good measuring stick.  All my Stegosaurs material was done privately and I believe "other than teeth" a good number sketal elements are sold that way.  The other thing you need to remember is that a number of Stego's are found as skeletons so sold that way to museums or others, possibly why the data in the chart above appears that way.:

 

At the Tucson show a few years ago someone was trying to sell a partial skeleton.  I enjoyed it since I was helping him set these up

 

 

 

 

 

 

[jpc]

Keep in mind, friends, that Susie's data analysis has nothing to do with what you might find for sale.  Her data come from published specimens.