New Dimetrodons: Fieldwork Update 2

[dinodigger]

Hi everyone, I'm finally getting to post another update on our field work in the Permian. We've had some great success but have also been hammered by this wicked storm that rolled through on Saturday. We woke up to some snow falling and then rain and could only shake our heads and sigh. We knew it meant another day or so delay. Once the dirt road gets wet, there's no traveling on it. And when we get to parts of the ranch with no roads... forget-about-it. Last thing you want is to be stuck out in the middle of nowhere in 20 degree temps.

Anyhoo, the ranch did favor us for a few days. Our main site exposed more of our Dimetrodon including a gigantic humerus, some new neural spines, and some other interesting creatures as well, including the femur of a cool reptile, Varanosaurus, and the vertebrae of a huge amphibian, Diadectes. Our newest location, Lucy Valley, is quite interesting from a geologic perspective as well as a Paleontologic one. The valley had us stumped for a few days, due to massive sandstone beds that dipped in toward each other from opposite sides of the site. The beautiful laminated sediments screamed pond environment. Obviously the sandstone had been laid down flat and then sometime later a massive deformation had occurred. In this case, the deformation occurred very slowly over a long period of time. The theory: Massive Ordovician salts or other minerals might have dissolved thousands of feet below the surface of our Permian environments creating a slow forming sinkhole. The presence of complete Dimetrodon skeletons are not due to the sink hole, we've concluded, but simply carcasses that fell in to the pond and became buried under the muck. The sink hole theory is one that might hold true to many parts of the Permian ranch as well. In this case we are dealing with carcasses in pond environments, but in other parts of the ranch, including our main site, we are dealing with floodplain deposits as well as channel deposits. But the concave sandstones seem to be present in multiple areas.

With the rains and snows finally gone, we can dry out and get back out there. So much to do, so much to see, so little time. We are all familiar with that problem. I've updated my Flickr photo-stream and it now includes photos of all the newest fossils and sites. Just click on the link below and it will take you to the pics. Click on the pics. Anyhoo, hope you enjoy. I'll have a new update in a week or two.

Chris

http://www.flickr.com/photos/45026327@N05/sets/72157623545872713/

[Auspex]

Complicated geology!

I take it the sandstone is indeed Permian?

[JohnJ]

Keep the great updates coming, Chris.

[MikeD]

That 40-50 mph wind that came along with that snow ought to help dry it out.

[Nicholas]

Reading your reports is like Christmas morning! I hope your weather luck changes and you get more collecting time in, the photos are fantastic!

I'm really becoming a fan of "Lucy"

[Smaug]

Wow,

One day, somewhere in the future, i would love to come to the U.S. and just have a look around. Just looking must be wonderful.

[MikeD]

Finally got to look at the pics. The internet filter at work blocks Flickr. Awesome! That shark cartilage looks similar to the piece I found at Brownwood this past weekend.

[TroyB]

Hey Chris, great photos and site info. I can't wait to see this one, when we get up there this week. Did I catch the site name as "Lucy" correctly?

I'm going to find lots of fossil poop here for sure.

TroyB

[dinodigger]

Hey Auspex, the sandstone is definitely Permian and is a great marker for different sites around the ranch. Now that we have a basic theory as to sink-hole formation, studying the sandstones will help us i.d. certain ecosystems as well. Certain sandstones have great ripple marks as well as varying grain sizes from fine to course. These are great for identifying the high and low energy flow patterns in the area which often transport many of the carcasses we are studying. Hopefully we will be able to correlate some patterns in bone beds as well as an image of the middle Permian ecosystems in North Texas.

Chris

Complicated geology!

I take it the sandstone is indeed Permian?

[dinodigger]

Hey Mike, I'd love to see a photo of the shark-lage you guys find at that site. It is Pennsylvanian material, correct? There are quite a few peculiar genus' of shark in that area and we may be able to I.D. the culprits.

Chris

Finally got to look at the pics. The internet filter at work blocks Flickr. Awesome! That shark cartilage looks similar to the piece I found at Brownwood this past weekend.

[dinodigger]

The Permian is truly unique wherever you see it. In Africa, in the Karoo, the late Permian beds are a spectacular view of the final days of the Permian world. Some great Paleo-magnetic research has offered some thoughts on how the Earth's magnetic poles reversed in the past, and evidence of this can be seen there. There are also some great critters there. The great Dimetrodon that we are studying here is gone, and some of the smaller guys that survive into the Triassic are getting ready for The Great Dying. Germany also has some great Permian beds; there is a little relative of the Dimetrodon there, kind of a tiny version of the N. American genus.

Wow,

One day, somewhere in the future, i would love to come to the U.S. and just have a look around. Just looking must be wonderful.

[MikeD]

Hey Mike, I'd love to see a photo of the shark-lage you guys find at that site. It is Pennsylvanian material, correct? There are quite a few peculiar genus' of shark in that area and we may be able to I.D. the culprits.

Chris

Well, I'm certainly no expert, but according to the TXGAT, it is Harpersville formation (Penn) with the Pueblo formation (Permian) running across the back side. There is a question mark by the Harpersville which looks like they don't quite know where the Penn stops and the Permian begins. It's all part of the Cisco group. Since the site has been mined extensively, it's probably a Penn/Perm mash-up. Neal took Dr. Bakker a piece a couple of years ago and he verified that it was shark-lage. I don't know that species was determined. I think it was one that Troy found. You'll have to ask him about it.

Here are a couple of pics of the one I found. The spot on top of the rock was what caught my eye. These would look better in the sun, but I just unpacked it. There was another interesting piece found that was completely without matrix on it, but I didn't get a picture of it.

[megalania]

I always look forward to the updates. I wish I was there. Keep up the good work

[TroyB]

Hi Mike and Chris, that shark-lage is difficult to tell weither it is Pennsylvanian or Permian as the Wilson Clay Pits are a mishmash of both. There are numberous 40 foot mounds of material dredged up from the pit 50+ years ago when they were dredging up clay for fine-fire bricks. I have found lots of it there and that piece you found Mike is probably from the mound in the back center of the property. That seams to be the only mound with shark-lage is found.

Here is a link of a document written by Dr. Neal Immega on the shark-lage found there.

http://www.hgms.org/Paleo/Shark%20Cartilage%20in%20Wilsons%20Clay%20Pit.pdf

TroyB

[bigade]

Hi Chris

Thanks again for the update and pictures, looks like you're finding plenty.

Can't wait for future updates.

All the best

Ade

[MikeD]

You are correct about the location, Troy. However, we have now confirmed a very large rock full of shark-lage was found a couple of mounds away, so our theory that all of it was confined to that one hill has now been proved to be wrong.