Morrison Formation...worth exploring or not?

[SPrice]

There is an isolated exposure of the Morrison formation nearby the area I have visited to hunt fossils the last few weeks.  The shape is an elongated oval and measures 1.15 km wide X 3.75km long. This image is a small section of it. 

 

My question is this: Would it be worth exploring, scouting, hiking this area for invertebrate fossils?  It is on BLM public land but keep in mind that vertebrate fossils are strictly off limits for collecting. The only reason I would even consider visiting it would be to hunt for invertebrate or plant fossils.  The majority of the area surrounding this "island" of Morrison formation is Cretaceous period  with the Juana Lopez Member of the Mancos Shale where I'm finding 4 species of ammonites. 

 

In my mind the old adage : when on a fox hunt, don't stop to chase rabbits...seems to apply to my question and for that reason I have yet to visit the Morrison formation spot. This case the fox is Ammonites and the Rabbits are dino bones, teeth, etc. It could be anxiety causing at worst and finding some nice invertebrate fossils at best. The anxiety being walking right past exposed bones, carnivore teeth, etc... which I wouldn't touch nor even photograph. The temptation to share would be another facet of the anxiety. Like - "Wow! I found Allosaurus teeth this weekend at ________ down in the Utah desert!"

 

Wiki says this about the Morrison fm fossil content :

Along the rivers, there were fish, frogs, salamanders, lizards, crocodiles, turtles, pterosaurs, crayfish, clams, and mammaliforms.

The dinosaurs were most likely riparian, as well. Hundreds of dinosaur fossils have been discovered, such as Allosaurus, Ceratosaurus, Torvosaurus, Saurophaganax, Camptosaurus, Ornitholestes and several stegosaur species.

 

A satellite view of a section of this Morrison fm "island"... The Junipers are probably 10 to 15 feet tall and a similar diameter.

 

 

[jpc]

As a seasoned Morrison collector I can tell you this.  Bones are easy to find.  Inverts and plants are rare.  One of the ranches I work on has dozens of bone sites and one plant site and one site known for its snails.  We are working a dinosaur quarry that has produced hundreds of bones...a nd one clam that I know of.   Also if anyone (BLM staff, for example)  sees a person walking around the Morrison with a rock hammer, you might get accused of vertebrate fossil poaching rather than "OK, go find those leaves and snails"  

 

Stick to the Juana Lopez.  That's my two cents.     

[SPrice]

3 hours ago, jpc said:

As a seasoned Morrison collector I can tell you this.  Bones are easy to find.  Inverts and plants are rare.  One of the ranches I work on has dozens of bone sites and one plant site and one site known for its snails.  We are working a dinosaur quarry that has produced hundreds of bones...a nd one clam that I know of.   Also if anyone (BLM staff, for example)  sees a person walking around the Morrison with a rock hammer, you might get accused of vertebrate fossil poaching rather than "OK, go find those leaves and snails"  

 

Stick to the Juana Lopez.  That's my two cents.     

 

Right there is the answer that works for me. Being new still at hunting fossils, I need experienced intel/insight like this. Ammonites are the interest and I have an entire state to legally collect in. Three more destinations are on my list. I have currently zero vertebrate fossils besides three white shark teeth from an antiques store in Shallotte, NC and the GRF fish from 2 private land, pay to dig, quarries in Kemmerer, Wyoming.  Probably going to stay that way, too. Trilobites are aplenty in Utah and maybe next year I'll try collecting those. Palms and sequoias are found  just east of the Juana Lopez - Mancos shale sites so plants are also on the list. Frankly, the left side bottom piece of a pelvic girdle from a  ( insert your fav dino here) is just not that appealing as a collectable specimen to me.  A carnivore tooth would be cool but not via breaking the law.

 

My parents gave me a military up bringing. Courtesy and obedience were high on the list of what we kids learned.

 

And not far down the list was the big C word- Consequences. 

 

Thanks, jpc, for your 2 cents.

[RuMert]

On 10/20/2023 at 6:50 PM, jpc said:

We are working a dinosaur quarry that has produced hundreds of bones...a nd one clam that I know of.

Nice to have a formation like this. All the sites I've seen was exactly the opposite

[SPrice]

This Morrison formation area on BLM land pictured above is 14 miles north of the Cleveland-Lloyd Dinosaur Quarry which is pretty much a world famous site well known for containing the densest concentration of Jurassic dinosaur fossils ever found. Haven't visited it, yet.

[patelinho7]

Is there something wrong with taking photos of vertebrate fossils in-situ? I feel like that would be the best way to enjoy those fossils whilst following rules.

[jpc]

1 hour ago, SPrice said:

This Morrison formation area on BLM land pictured above is 14 miles north of the Cleveland-Lloyd Dinosaur Quarry which is pretty much a world famous site well known for containing the densest concentration of Jurassic dinosaur fossils ever found. Haven't visited it, yet.

I think Cleveland-Lloyd's claim to fame is the densest concentration of Allosaurus bones.  I think the Howe Quarry is pretty much denser in Jurassic bones.  This is my opinion, based on memory, not fact.  And maybe the Nail Quarry will rival it.  Stay tuned....  

[jpc]

18 minutes ago, patelinho7 said:

Is there something wrong with taking photos of vertebrate fossils in-situ? I feel like that would be the best way to enjoy those fossils whilst following rules.

Nothing wrong there; this is perfectly legal and even encouraged.  And then you have the data to help report anything you might find.  As a museum worker, one of the first things I ask folks who have found bones in the field is... can you send me a photo or two?  

Edited October 27, 2023 by jpc

[SPrice]

To clarify what I said about not taking pics. It's because I won't be visiting the site...no other reason.  I can see it when I drive by it on my way to the Ammonite concretions. Nice banded colors with occasional  Razors, side by sides, Jeeps,  driving around the area. It's fairly scenic as is the entire desert surrounding it. 

 

My trips are 2-4 hours drive time each way so I make the most of the time I have hunting/collecting for day trips.  And a side trip for pics is usually not on the agenda. Fossil hunting ...not rabbit chasing.

 

My comment about the CL quarry was a Wiki quote...I only know a drop in the bucket about it being a mud pit which trapped some dinos which attracted predatory dinos and trapped them , too.  And that might be wrong as well.

[Andúril Flame of the West]

5 hours ago, SPrice said:

 

My comment about the CL quarry was a Wiki quote...I only know a drop in the bucket about it being a mud pit which trapped some dinos which attracted predatory dinos and trapped them , too.  And that might be wrong as well.

 

I have read a bit about the Cleveland-Lloyd Dinosaur Quarry. From what I gather, it seems that one of the explanations with the strongest backing is that the quarry was an anoxic algae-choked pond that formed during seasonal flooding. Dinosaur remains would be washed into the pond during flood events and the anoxic environment assisted in preservation. However, this may not be the most up-to-date interpretation and I am sure that @jpc is far more knowledgeable on this. 

Edited October 27, 2023 by Andúril Flame of the West

[Jeffrey P]

The Salt Lake City Natural History Museum has an exhibit on the Cleveland/Lloyd Dinosaur Quarry which proposes a number of different theories about how the fossil bones were concentrated there.