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Opabinia Blues

I just got back from an amazing and very fruitful week of fossil collecting on the White River Formation in northeastern Colorado. The White River Formation is a very easy and fun rock unit to collect vertebrate fossils on. The White River Formation was deposited during the very latest Eocene and the early Oligocene, though the faunal diversity in the areas I was collecting on suggest it was laid down during the Orellan North American Land Mammal Age, which centers on around 33 million years ago during the Rupelian age of the Oligocene Epoch. 

 

I am very lucky to have a grand uncle Gary (no biological relationship to me, is a close family friend who we’ve called “uncle” since I was a toddler) who is a cattle rancher up in northeastern Colorado, and he happens to have a pretty good amount of White River exposure on his property, in addition to some of the neighboring ranches of which Gary knows the owners and helped me to secure permission to collect on a few of them. He really is a great guy and is a real life true American cowboy. He has an interest in natural history and was eager to hear all about the fossils and geology of the area, though has never had the formal education or done the research to learn much about what’s out there.

 

This is the second fossil collecting trip I’ve made to the ranch, though the first one where I’ve stayed for more than one night. The place truly is an amazing trove of fossil treasures and I can’t wait to tell you all about my week! In this thread I’ll make one post for each day (so as to not hit the picture limit too soon). Once I have the fossils prepped I’ll give updates here as well.

 

Day 1, Sunday:

My first day at the ranch began, ironically, at my own house. I had packed up the Jeep the night before with my field bag, two coolers filled with seven day’s worth of food, a suitcase full of clothes, and other such supplies for my fossil safari. I left my home early in the morning, took I-76 east to Fort Morgan, and then headed north to the ranch, in total about a 2.5 hour drive.  

 

The rest of the morning and early afternoon I spent visiting with and going over logistics with Gary and his wife and settling in at the ranch house I would be staying at, a property that used to be the home of another rancher before Gary acquired the property in 2002. They still maintain the house and it has both electricity and running water, so it makes a fantastic guest house and a place to stay when they’re doing work over on that side of their land. 

 

In the evening after I had made myself a quick dinner I decided I wanted to head down to a very productive exposure I had collected on last September for the evening. There was a partial oreodont skeleton that I had discovered eroding out of the hill the last time I was up there, and I wanted to see if there were any more bones there that had eroded out and I could collect. I picked up a few more bones from the feet and ankles that had been exposed in the last eight months and decided to take a scenic route back to my vehicle.

 

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A photo of the area of exposure I was in Sunday evening. This piece of badland will become very important throughout the rest of the week...

 

On my walk back I walked over a ridge that I had apparently never been over, becase on a flat wash I noticed a pile of bone fragments. I approached the pile assuming that it would be yet another exploded tortoise shell that are so common in the area. As I got closer however, I was delightfully surprised to see the distinctive black color of fossil enamel, and a bit of digging revealed an eroded Subhyracodon jaw section, along with several loose teeth that I presume had come from the same section of jaw. This find, along with an oreodont jaw section I found later on while walking back to the Jeep that night, would be but a foreshadow of the big finds I would make later in the week.

 

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Two photos of the Subhyracodon jaw section as it was found in the field.

 

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The jaw section and some teeth after I had cleaned them up a little bit at home this afternoon.

 

Edited by Opabinia Blues
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PrehistoricWonders

Can’t wait for the rest of the report! That Rhino Jaw is awesome! Would be a dream find for me!

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Opabinia Blues
Posted (edited)

Day 2, Monday:

Despite a severe lack of quality sleep due to my own excitement, I went out into the field on Monday with a logistical mission: to scout for additional productive sites on the ranch. You see, on this particular ranch the exposures of White River Formation are numerous, but none of them are particularly large. The exposures are fragmented, which makes it difficult to find new areas which are both productive and easily accessible. Therefore, I had planned to explore several new areas which I could see through satellite imagery, which is a lot easier said than done given that there’s a strict “no driving on the grass” rule. 

 

This effort took the entirety of the morning, and unfortunately was generally not very fruitful. The White River Formation, in my experience, has this tendency to be very inconsistent; in some places you’ll be practically tripping over fossils and in others there will be literally nothing there, and as far as I can tell there’s no way of figuring out how productive a spot will be until you’re there. I’ve had this experience with the White River Formation in both Wyoming and Colorado. Unfortunately most of the exposures I were scouting turned out to be of the “absolutely nothing here” variety, despite being fairly sizable. I hiked around in each for a good half hour, and though I don’t necessarily expect to make the find of the week within a few minutes it has been my experience that if you’re not seeing at least a few bone fragments or bits of tortoise shell laying around then there’s probably not much there.

 

I did however eventually find an area that seemed to have potential, as within just a feet of the trail there was a tiny but of oreodont jaw with a tooth stuck in it. I took this as a good sign and decided I’d spend the day exploring that particular exposure. Thing is though, this little bit of exposure was unusual in that it stuck out from the side of a deep bluff and deep canyons cut into the rock, very different from the low lying rolling hills of mudstone that are typical of this rock unit. 

 

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I headed down one of the canyons, excited to be in an area with more potential but also a bit peeved that the twenty foot canyons would make prospecting much less efficient. On the way down I ran into quite a few tortoise shells eroding out of the rock. These tortoises are laughably common in certain members of the White River Formation, however most of them are uncollectible either because they have already exploded on the surface or desintegrarte into dust when you try to dig around them. Thus, on my descent down the canyon I was zero for three on attempting to excavate tortoises.

 

I did run into something else interesting though on the way down, of the non-fossil variety: two desert rose crystals, one laying out in the open and one half buried within the White River rock, both within ten feet of each other. They’re very beautiful, if incredibly common, structures and I was happy to collect them, though I wasn’t ever expecting to see something like that, despite the fact that I knew of the high quartz content of White River exposures. In my later research I couldn’t find any mention of these crystals coming from White River Formation nor any mention of them being common in Colorado. It would be great if someone who is more knowledgeable about this topic could fill me in!

 

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After I reached the bottom of one canyon I headed back up the one adjacent to it. Near the bottom I noticed the edge of yet another tortoise shell eroding out of an accessible hillside. I decided to try my luck once again on digging up a tortoise, so I clambered up the precarious hillside to reach the petrified reptilian, bracing myself up with a nearby plant so that I wouldn’t slide down the hill.

 

I used my knife and rock hammer to start slowly chipping away the mudstone around the shell, and to my delight and surprise, most of the shell stayed in place as I worked! About 1/3 of the shell had either already been lost to erosion or sloughed off as I worked due to being cracked beyond repair by the previous winter’s freeze thaw cycle, but with a liberal application of red PaleoBond penetrant stabilizer I began to realize that could get most of shell out intact.

 

The excavation of this tortoise was probably the toughest paleontological challenge I have yet faced. Remember that I was on a steep grade bracing myself up on the woody stem of a plant. The rock gets harder and more difficult to work with as you dig further down, plus it became very difficult to differentiate what was matrix from what was shell. The annoyances of the blistering sun and my PaleoBond coated fingers weren’t exactly making the whole process easy either. 

 

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The tortoise shell as the excavation went on. The matrix is still holding the original shape of the shell but it’s only about 2/3 complete. 

 

The entire excavation took roughly 2.5 hours, with the shell ending up being roughly sixteen inches in diameter. I was just happy to get the thing out and that I finally had a mostly complete White River tortoise in my possession. I wrapped the shell in foil, and in order to get it out I went back to the Jeep to retrieve the metal sled that I had brought specifically for an occasion such as this one. I dragged the tortoise about 1/2 mile out of the badlands and back to the Jeep, bringing the total time for the entire tortoise ordeal to around three hours or so. 

 

It was only 4:00 PM by the time I had the tortoise in the vehicle, so there was plenty of daylight left in the day to prospect some more. However, I was so tired and so hot that I decided to just call it a day there, so I drove back to the house, took a nap, and had dinner. A White River tortoise was one of my wishlist fossils to have in my collection, so I was glad to finally get one out reasonably intact.  

 

 

 

 

Edited by Opabinia Blues
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fun stuff.  Great report.  Have you ever considered using Vinac or Paraloid B-72 as a field consolidant?  I find that PB penetranr/stabilizer does not want to come off of white river fossils.  When I do contract work prepping White River stuff I do warn customers that if they use PB as a consolidant, it will almost double the prep time, esp if it is directly on the bones/shell.  

 

Just a thought.  

 

Looking forward to the next installment

Edited by jpc
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Opabinia Blues
2 hours ago, jpc said:

fun stuff.  Great report.  Have you ever considered using Vinac or Paraloid B-72 as a field consolidant?  I find that PB penetranr/stabilizer does not want to come off of white river fossils.  When I do contract work prepping White River stuff I do warn customers that if they use PB as a consolidant, it will almost double the prep time, esp if it is directly on the bones/shell.  

 

Just a thought.  

 

Looking forward to the next installment

You’re the third person now to tell me that. Too late now though, is what it is. I’ll bite the bullet on this one, I’ve already placed an order for a bunch more of that solvent stuff that they sell. I know it only works very well on the very surface, but I figure I’ll just have to scrub off the excess. I have some Vinac, I just didn’t think about using it in the field. I have so little prep experience I wasn’t aware of the issues with PaleoBond. It does the job of holding stuff together really well though.

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The mineral is probably barytine (baryte). It’s a pretty heavy mineral.

 

Coco

 

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hemipristis
1 hour ago, Coco said:

The mineral is probably barytine. It’s a pretty heavy mineral.

 

Coco

 

The crystal structure resembles barite instead of gypsum. I concur

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Ludwigia

Excellent report. Thanks for taking us along. :popcorn:

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Looking forward to seeing the tortoise cleaned up.

 

RB

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hadrosauridae
6 hours ago, Opabinia Blues said:

You’re the third person now to tell me that. Too late now though, is what it is. I’ll bite the bullet on this one, I’ve already placed an order for a bunch more of that solvent stuff that they sell. I know it only works very well on the very surface, but I figure I’ll just have to scrub off the excess. I have some Vinac, I just didn’t think about using it in the field. I have so little prep experience I wasn’t aware of the issues with PaleoBond. It does the job of holding stuff together really well though.

 

If youve already ordered it, then go ahead and use it, but all you really need for CA removal is acetone.  The acetone only softens the CA glue and only while its wet, which takes a few minutes and it dries VERY fast.  What I do is to use a q-tip or cotton ball with acetone and wipe the SMALL area you want to clean, keep wiping, and keep re wetting with acetone and keep wiping.... If its a thin layer it will wipe off pretty easy, if it has a thick coating (with matrix and dirt, etc) then you can use a small DULL blade to scrape off the bulk of the softened glue from the spot and then detail clean with a Q-tip and acetone.  

 

You also have to be careful because if you have nearby breaks that are glued with CA, the acetone will seap into those and soften the join which can lead to the break (breaks) falling apart from handling before the glue has fully solidified again.  Even though acetone dries extremely fast, it can take a while once its gotten deep into the bone / break.

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siteseer

I like Paraloid too.  Acetone is cheap at Home Depot though you might find a better deal elsewhere.  It's a mild solvent but you should wear gloves and use it outside - fumes are not good for you.  And always wear your safety glasses when prepping or thinking about prepping.

 

 

 

 

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11 hours ago, siteseer said:

I like Paraloid too.  Acetone is cheap at Home Depot though you might find a better deal elsewhere.  It's a mild solvent but you should wear gloves and use it outside - fumes are not good for you.  And always wear your safety glasses when prepping or thinking about prepping.

 

 

 

 

: )   Safety glasses when THINKING of prepping.  I love this.  

 

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Opabinia Blues

Day 3, Tuesday:

 

On Tuesday I was set to go out and hunt for fossils on one of the neighboring ranches, with Gary having previously helped me secure permission to collect there for the day. This ranch has several very large exposures on it, so needless to say I was quite optimistic indeed.

 

The trail closest to the exposures on this ranch terminated right by a small creek, which most of the time during the summer would by dry but when I was there happened to have some marshy water filling the bottom of it. There are White River exposures along the banks and bottom of this creek, but I wouldn’t be able to prospect there because of the water. This also foiled my plans to use the dry creek to hike the 1/2 mile out to the larger pieces of exposure on the ranch. I hate walking through tall grass out on these ranches because of the potential for rattlesnakes and ticks, though many days I’ll do just about anything for fossils.

 

Before I made the trek out to the main exposure, I noticed that to my vehicle’s left, about twenty feet away, there was a small section of “rolling hills” exposure that’s pretty easy to prospect on, so I decided to start the day off looking there, figuring I could check every hillside and wash in the vicinity within 20-30 minutes.

 

This bit of exposure was a different color than most of the White River mudstone rocks that I’ve seen; it was a distinctive brown color whereas generally the fossiliferous areas of White River rock are a grayish-greenish-white color. I hiked around for maybe fifteen or twenty minutes in a very methodical back and forth method in which I’d always check the exposed hillsides to my right while making back and forth sweeps across the area of exposure, which at least in theory should allow me to see everything that might be out there.

 

I was at first disappointed that I was seeing no fossil material - no bone fragments, no pieces of tortoise shell, nothing. My luck changed though when I made my final turn back towards my Jeep and saw this nice bit of bone sticking out of ground:

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Just seeing this little bit made me immediately excited! It was literally within thirty feet of my Jeep, in fact I had walked over that same hill as I was heading out earlier to prospect on this little bit of badlands. I laid my items down and began the excavation, which was very easy at first as all I had to do was brush away the eroded matrix which was on top of it and apply a bit of PaleoBond to keep the thing intact (yes yes, I know now, PaleoBond bad in the field, especially for White River fossils).

 

My first instinct was that this was a long bone of some sort, but as the shape of the bone became more clear and I uncovered the roots of the teeth it became obvious that I was actually looking at a jaw bone, and one from a large animal at that! I uncovered the top of the jaw bone fully, mostly with a brush but then near the end using my knife like a chisel, and then dug a trench around the whole thing with my rock hammer. From there I was once again able to use my knife as a chisel and lift the entire bone out on top of a slab of rock to keep it stable, if that makes any sense. 

 

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Though there were several cracks running through the bone I was in general very pleased with how intact it was for being so close to the surface and probably taking the full brunt of last year’s freeze-thaw cycle. The entire excavation took about twenty minutes and the jaw ended up being just under twelve inches in length. The teeth were still encased in matrix as well, which only added a bit of mystery to this discovery (though looking back it should have been pretty obvious what this was... will reveal everything in the next post). 

 

I wrapped the bone in foil, carried it back to my vehicle, and wrapped it in a blanket to keep it secure. From there I headed out in the opposite direction across open grassland to reach the rest of the exposure on this area of the ranch.

 

The rest of the day was semi-productive: finds included several bits of oreodont jaw, a Leptomeryx jaw section, and many exploded tortoise shells. This was fine with me, seeing as I had made the best find of the week so far first thing in the morning. This particular day was the hottest of the week, and the reflection off the badlands only makes everything hotter. As I sat down for lunch my thermometer was reading well over 100 degrees Fahrenheit. This combined with the fact that I had run out of water, both in my canteen and in my reserve bottles, made me hike the now 3/4 mile back to the vehicle, and by the time I got there I decided I’d just call it a day since I made a good find. So really Tuesday was more a half day of collecting, which will be a recurring theme throughout the week due to various factors.

 

As soon as I can I’ll update everyone on that jaw bone! Will probably start writing that update right after I post this one.

 

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Opabinia Blues

Jaw bone update:

 

I have put several hours of work into prepping that jaw bone now, and I would say I’m roughly 80-90 percent of the way through all the prep work that could be done on it. What I ended up having to do is first do some large-scale matrix removal with the air scribe to expose the teeth and free the bone from its rocky pedestal. I then had to separate many of the areas where the jaw had become cracked and clean those areas very thoroughly as matrix had seeped into the space between the cracks, before re-setting and re-gluing the pieces back together. From there I had mainly been working on finer cleaning with an exacto knife, which as I had been warned is turning out to be a major pain (though certainly not impossible). There are still some areas of discoloration due to the PaleoBond which needs to be scraped off, and the teeth could be cleaned more thoroughly as well. I am also considering filling in a few of the cracks with a light colored epoxy so they are less obvious, though I would like to hear people’s opinions first before I attempt it.

 

I should probably reveal its identity as well: its from a juvenile/adolescent Subhyracodon. There are several interesting things about this jaw that led me to this specific conclusion, and I was lucky to confirm with an actual mammal paleontologist via Facebook that it is indeed from a juvenile/adolescent due to the presence of both juvenile and adult dentition (more on this after the pictures).

 

Before:

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After:

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Buccal side

 

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Lingual side

 

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Occlusal view

 

The first interesting thing to notice about this jaw is that the very back molar is unerrupted. It’s there, you can see it in the socket, but it has yet to push its way up past the jaw line yet and obviously would have been below the gum in life. Notice as well that you can see the roots of the premolars which would not be visible life. I suspect that this is due to postmortem tooth slippage, as can be observed in modern jaw bones as they start to decay. There are several strips of bone that are missing, this is not an error on my part, it was in the ground this way and fossilized this way, which suggests that the bone had been on the surface for quite some time and weathered before being eventually buried and fossilized. This combined with the tooth slippage suggests that the animal had been dead for quite some time before this bone was buried. The Subhyracodon died, the bones were scattered by weather and scavengers, and the jaw bone was out in the open for quite a while as it started to weather away and the teeth began to slip out of their sockets. But then the bone was covered by mud, and as mud turned to mudstone it became mineralized and preserved as a fossil for me to find. This taphonomic hypothesis is further supported by the fact that the bone was in the ground on its side and parallel to the ground, a position you would expect it to be in if it had been laying on the ground on its own.

 

Any suggestions anyone may have as to further prep I could do to make this bone look as good as possible would be greatly appreciated!

 

 

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PaleoNoel

Awesome jaw Quincy! When you had shown me that jaw when you first found it my guess was subhyracodon based on its size alone. Congratulations! I need to finish up prep on my own rhino jaw soon but I still need to get a couple tools for that job.

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Great find.  

 

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Opabinia Blues
36 minutes ago, PaleoNoel said:

Awesome jaw Quincy! When you had shown me that jaw when you first found it my guess was subhyracodon based on its size alone. Congratulations! I need to finish up prep on my own rhino jaw soon but I still need to get a couple tools for that job.

Thank you very much!

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hadrosauridae

You're prep is looking great so far!  For the remaining portion of the jaw, you'll need to  use acetone to soften the paleobond enough to separate the pieces.  Those bits can definitely be remounted with a much smaller gap, if not completely touching.  If youve never separated bits like this, it can feel very nerve wracking, but go slow and it will be fine.  Soften and clean the matrix from those edges, re-solidify with PB-02, then re-join the parts.

 

As for the epoxy use, I'll tell you the same thing I learned here; ONLY IN-BETWEEN, NEVER ON TOP.  Look very closely at the texture and grain of the bone surface.  Once you fill a gap, you want to try to mimic that look.  For the fossils I have repaired, I found that a small, stiff bristled tooth brush work well.  I would tap it along the putty to give it a stippled look, or drag it along with the "grain" of the bone.  It doesnt have to look perfect, you arent trying to hide the fact there is a repair, you are just trying to make it not stand out glaringly.  

 

edit to add - The last step your jaw will need is micro-blasting.  I know youre not there yet, but I bet you will have one before too long.  micro air abrasion can remove the final layer of matrix and glue that you can really do with tools.  IT would probably make those teeth look fabulous too.  Once its completely done, a coating of Butvar-76 to seal and protect. 

Edited by hadrosauridae
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excellent advice from hadr, but I would skip the final step.  White River materialis generally strong enough to not need to stabilized.  BUt that is my personal take on it.  

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Opabinia Blues
Posted (edited)

Day 3 and 4, Wednesday/Thursday

 

I am combining these two days into one entry because I only really fit in a single day worth of collecting over these two days. I had to assist Gary with some ranch work, including loading some cattle in a trailer to sell them down in Brush (town in CO south of where I was). I feel like assistance with chores in exchange for land access is a pretty good trade to make, so I was happy to help out.

 

On Wednesday I spent my time collecting in that same productive site off the main trail where I was at on Monday. I only had a couple hours to collect, but that was enough time for me to locate a few nice astragalus bones, vertebrae, and carpals, in addition to some more oreodont upper jaw sections. The best find of the day came in the evening in the form of this jaw section from an insectivorous mammal, which I have tentatively identified as Leptictis thanks to the detailed information and images in my reference book The White River Badlands: Geology and Paleontology (Benton, et al. 2015). This work is a must have for anyone doing fossil collecting in the White River Formation, it has been so enormously helpful to me and I have learned much from it.

 

6BDECBAD-82F5-4EAD-B7D5-714DD5E3817A.thumb.jpeg.2bfa0439837a70b6de3e179358575bd6.jpeg

Insectivore cf. Leptictis jaw section with three teeth. Not the best picture, I know. 

 

Before I move on let me just rave a little bit more about this particular site: it is the single most productive piece of White River Formation exposure I have ever been on, period. I guess this isn’t saying too much since I’ve only been collecting White River stuff for about a year now, but it’s still pretty amazing. I haven’t found too many “big” (in terms of size) things here, but the sheer quantity of fossil material is amazing, it’s like a 1-mile-squared microsite. Fossils are everywhere, you can crawl across the ground and be picking little stuff up all over the place. I will walk back over places that I thought I had already picked over pretty thoroughly and find yet more stuff there. It’s mostly common material, lots of oreodont teeth and bones, lots of tortoises, and lots of Leptomeryx stuff (including a mostly complete jaw). I have found quite a lot of interesting stuff here as well though on previous trips, such as several coprolites, really nice quality oreodont bones (that are so well-preserved they look almost like they came straight from the living animal), and my huge 6-inch canine tooth (either entelodont or Metamynodon, I float back and forth between which it could be). And of course I made a few other good finds on this site as well during this trip, such as the Subhyracodon jaw section and teeth that I found on the first evening and another big find that will come on Friday.

 

Ultimately, even though I’ve looked over about 80% of this exposure pretty thoroughly I am hoping the area will continue to produce finds for several seasons to come. 

 

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One of several mammal vertebrae centrums I found at this site on this trip. 

 

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Herbivore jaw section, pretty sure it’s just oreodont. 

 

On Thursday I was able to spend the morning collecting on another neighboring property thanks to help from Gary. This time I was on a ranch that’s a little bit of a local legend among the ranchers in the area for its fossils, because apparently back in the 30s when the grandfather of the current ranch owner was running the property a crew from the Smithsonian natural history museum recovered two complete or near-complete skeletons from the ranch that are now on display in Washington D.C. According to the rancher who owns the property the two skeletons were “a prehistoric horse” and “a big pig-thing” which tells me they were probably either Mesohippus or Miohippus as well as an entelodont. This rancher also has a Stylemys tortoise shell in his living room that he and his son dug out on their property. So this area has a history of good fossil finds.

 

Unfortunately for me, the few hours I spent collecting on this ranch in the morning were only moderately productive. Lots of tortoise shell pieces and a few bone fragments were most of what was there, with the highlight probably being this section of Hyracodon jaw with 1.5 teeth in it. Certainly not the week’s best find, but it’s the first bit of identifiable material from the “Running Rhino” I have been able to recover, so I’m still fairly pleased with it. 

 

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Hyracodon jaw section.

 

Around lunch time I had to head back to Gary’s ranch and help with some more work, which took the rest of the day.

 

Stay tuned for the next and final installment in addition to a final wrap-up, whenever I get the time to write them. Thank you to everyone who’s followed along and has been enjoying reading.

 

 

 

Edited by Opabinia Blues
Fixed a typo.
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Sjfriend

Awesome! Great report. Wait for more :popcorn:

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Opabinia Blues
Posted (edited)

Day 6, Friday:

 

The excitement that Friday started off not with fossils, but with yet another ranch operation. By this point all of Gary’s cows had given birth and the calves had been branded, and so it was time to move the cows and their calves from the calving pasture about ten miles to a different pasture... which just so happened to be the same pasture where the site I wanted to collect at is located. I was asked not to collect while they were moving cattle, and so I actually ended up riding along in a four wheeler during the cattle drive, which was actually a rather interesting experience that I snagged some photos of, for anyone interested:

 

BDB2470F-BFB3-4EEB-AA66-4319CDF63D68.thumb.jpeg.1aab848899aa0fea6596a69309ddaf02.jpeg

 

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The cattle drive took all morning into the early afternoon, but after lunch I was ready to head back down to my favored productive spot with the intent of following a creek bed north for a few miles to reach some additional outcrops I hadn’t been on yet. It was there that I spent the rest of the late afternoon until sunset partaking in my last day of fossil collecting for the week. The good news is that the already productive spot only got better and better the further north I went, however the outcrops became thinner and thinner which reduced the efficiency of my prospecting.

 

I am unfortunately typically pretty bad at remembering to take photos of stuff I find in the field, but I can certainly describe some of the interesting finds I made Friday: more small oreodont and other artiodactyl bones, astragaluses, metatarsals, etc., more vertebra centrums and one mostly complete thoracic vertebra with the processes still reasonably intact, and lots of oreodont/camel and Leptomeryx jaw sections. I had a strange but exciting moment where I was pulling what I thought were bone fragments out of my pockets only to realize that most of them were jaw sections with the teeth still intact. I’ve done this before while White River collecting, which is why I always pick up bone fragments and examine them later, because several times they’ve ended up being more significant.

 

A semi-interesting find was this distal end of a femur from a large animal (once again my mind wanders to rhino/entelodont, but I still have to prepare it before I can confidently get an ID):

90B9A99E-00CD-4195-83B0-B6063113F276.thumb.jpeg.d1fb7a412dcd2b674257b2ebd3f79917.jpeg

 

Another smaller highlight of Friday was perhaps this Poebrotherium jaw with the majority of the molars and premolars intact: 

72935C88-5487-4DAA-84FA-A8BE212C083D.thumb.jpeg.4f9ba0975b144dd79f0dc76d7cbeba17.jpeg

 

But of course, seeing as time is always ticking and the earth continues to spin, the sun eventually began to set along the horizon and the day was coming to a close. I knew that I needed to cut back across the pasture to get back to my vehicle before dark, but decided that I would take a glance at just one more hillside before walking back. And as I came over the top of the gully and looked at the mudstone glowing orange under the evening sun, there staring back at me was the skull of an oreodont.  

 

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I threw my hands up in the air and let out a hollar of excitement. I had finally found one! You see, this is definitely a good find by anyone’s measure, but an oreodont skull had been on my personal “want to collect” list for just about a year since I returned from my first collecting experience on the White River Formation with PaleoProspectors in 2020. On that trip I was one of maybe two or three participants that did not find an oreodont skull. They were turning up left and right in Wyoming and almost everybody got to bring one home, so I felt pretty left out on this front. This find therefore has a bit of personal sentiment and significance for me, and to find it on the very last day, just as the sun was setting as literally the last find of the trip is poetic. I finally feel vindicated. I wrapped up the skull and took a very happy walk back to the jeep as the sun dipped under the horizon.

 

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White River exposure at sunset.

 

And as such, that finishes up my report on my trip out to the Colorado section of the White River Formation. It was a very productive and very fun week, and I feel so lucky to have the connections necessary to have made it happen. I’ll be heading back up to this same ranch in a few weeks with @PaleoNoel and @Mickeyb06 as part of our two week fossil hunting road trip, and I hope we can make a few good finds out there once again. After I post this I’ll start on the “wrap up” where I’ll list out all the finds I made. Thank you to everyone for reading and enjoying!

 

Edited by Opabinia Blues
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Opabinia Blues

Wrap up:

 

So here was the final haul of identifiable for this weeks collecting trip:

  • Various bones and parts of bones, including the ends of long bones, five vertebrae, three astragalus bones, and various small bones that make up feet and ankles.
  • Jaw sections with teeth, including six oreodont (or camel), one Poebrotherium, two Leptomeryx, one insectivore (likely Leptictis), one Subhyracodon, one Hyracodon, and one unidentified.
  • One subadult/adolescent Subhyracodon jaw with an unerrupted molar.
  • One oreodont skull, probably Merycoidodon.
  • One coprolite.
  • One 2/3 complete tortoise shell.

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Some of the finds.

 

Here’s a better picture of that oreodont skull. Still unprepared, but at the moment I’m just displaying it as-is:

2C123EF3-686F-4934-8896-C936142EDE59.thumb.jpeg.8b4f9426aad0e44c2c859a392e693c7d.jpeg

 

And of course, the rhino jaw in better lighting:

2492976A-FC3B-4A22-9C53-A63D15A5AD51.thumb.jpeg.291125a2e5373916cb98c83bc5152167.jpeg

 

I might add that the jaw is up for VFOTM for June, and I encourage all of you to go ahead and cast your vote for it when the poll opens ;)

 

Thanks again everyone, I’m glad I got to document this trip on here with other enthusiasts. Have a great rest of your summer, everyone! I wish you all great finds and plenty of adventure!

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hadrosauridae

Great ending to your trip! Congrats on the awesome finds. That skull is fabulous.

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