Jim's Trips

[Ludwigia]

I'd love to have a spot where I could just pick things out without even having to bend down! That would suit these old bones (and muscles) just fine. Isn't that always the case that well-preserved fossils in dolomite are pretty scarce? Seen that trilo before. Great find. Those big ostracods are impressive for someone who's only seen them under a microscope.

[Fossildude19]

Great finds, again, Jim!

Thanks for showing them.

Regards,

[JimB88]

I'd love to have a spot where I could just pick things out without even having to bend down! That would suit these old bones (and muscles) just fine. Isn't that always the case that well-preserved fossils in dolomite are pretty scarce? Seen that trilo before. Great find. Those big ostracods are impressive for someone who's only seen them under a microscope.

It would be interesting to find out why they were so large then..and why the micro ones survived where as the big ones could not.

[Mike from North Queensland]

Some nice trips and some nice finds

Mike

[Ludwigia]

It would be interesting to find out why they were so large then..and why the micro ones survived where as the big ones could not.

I dunno. When you think about it, a lot of things got big at different stages in time and then shrunk back down again or died out completely. There must have been a lot of different factors involved which caused the various cases of gigantism which breached the globe at various stages, not just an increase of oxygen in the atmosphere, but I can't think of what might have been going on with this order during Ordovician times. Was there other fauna which was larger than usual at the time, or was it just the ostracods?

[Auspex]

It would be interesting to find out why they were so large then..and why the micro ones survived where as the big ones could not.

Ask "what did they eat, and what about that resource changed?" Something as remote as a reduction in nutrient runoff due to global drought due to global cooling could be a root cause. It's freaking complicated!

[JimB88]

I dunno. When you think about it, a lot of things got big at different stages in time and then shrunk back down again or died out completely. There must have been a lot of different factors involved which caused the various cases of gigantism which breached the globe at various stages, not just an increase of oxygen in the atmosphere, but I can't think of what might have been going on with this order during Ordovician times. Was there other fauna which was larger than usual at the time, or was it just the ostracods?

At this site its just the ostracods, but in the late Ordovician rocks of arctic North America, many forms grew larger than average as this area was at the equator and the seas were rich with nutrients.

[JimB88]

Ask "what did they eat, and what about that resource changed?" Something as remote as a reduction in nutrient runoff due to global drought due to global cooling could be a root cause. It's freaking complicated!

that is very true..they could also have been out-competed in their niche by newly evolved organisms.

[Ludwigia]

You are what you eat, I guess...

[JimB88]

Went out again yesterday, back to check more of the third stop in my last report hoping to find trilobite goodness. I didnt but I still found some neat stuff!

This site is the Middle Ordovician Hermitage formation (Nashville Group)

Other than the usual scores of small brachiopods like Rhynchotrema increbescens and Onniella I found a pair of small Platystrophia extensa

these guys are small (especially when compared to the ones found later )

Though Im going to slow down on the bryo collecting I still found some nice ones!

Prasopora patera

Hallopora sp.?

a couple of unidentified ones.

Then a rare cephalopod from the transitional zone

probably Actinoceras sp.

after an hour of the sun beating down I decided to move on and do some scouting. I stopped on a side road a couple of times but didnt find much beside some strophomenid brachiopods and this small cephalopod:

not sure on the genus at this point. Or the formation as the USGS map is rather vague...

cont...

[JimB88]

After traveling a bit further I found a rather shady cut to explore, but since the previous two stops pfoved fruitless, I didnt have high hopes.

Fortunately I was wrong...

I began by finding these huge brachiopods! They reminded me of Platystrophia but Ive never seen them so big.

the group of them I picked up.

close ups of an individual one.

This one has a bryozoan attached to it!

This one is about the average size I had been finding at my other sites. It has a worm tube of some sort on it!

cont...

Edited July 19, 2015 by JimB88

[JimB88]

cont...

another shot of this one.

The largest I found was a single valve example (which were more numerous than the complete ones.)

And those weren't the only ones big at that spot..

Thanks again to Bill for the help in Id'ing it as Rafinesquina sp.

This is the largest of these Ive ever found!

Along with the brachiopods were a few mollusks..

The bivalve Ambonychia sp.

the gastropod Lophospira sp.

The question of which formation I was in is vexing as the usgs map lists three groups with seven possible formations. Add to that the fact that the Silurian also is present there (and that many Upper Ordovician fauna carried on into the Silurian) makes it doubly hard. I found out about the Silurian being there after I finally got home (I was locationally challenged for a time ) and checked the USGS site map of TN. I'll have to go back to that area and try to find some Silurian (if I havent already) since Ive never collected in that period.

[Ludwigia]

Those are some humongous Brachis! Almost makes you forget the trilobites!

[JimB88]

Those are some humongous Brachis! Almost makes you forget the trilobites!

actually it did..I was excited!

[ZiggieCie]

The photo of the brach with the tube worm on it. the worm may be the Cornulites proprius Hall. On the link here it is about 3/4 down the page on a Platyceras.

http://www.fallsoftheohio.org/Fossil_Worms.html

[JimB88]

The photo of the brach with the tube worm on it. the worm may be the Cornulites proprius Hall. On the link here it is about 3/4 down the page on a Platyceras.

http://www.fallsoftheohio.org/Fossil_Worms.html

It does look like one doesnt it? If so, it would be a first!

[ZiggieCie]

Here is a link on "Strophomenacean Brachiopods from the Ordovician of Kentucky." It has some hi tech talk in it but also some good info, with interesting plates at the end. For me it runs rough on-line but should be fine downloaded and opened on Adobe reader.

http://books.googleusercontent.com/books/content?req=AKW5Qad1VXthTqY21jSj8rncXpihhg_DaOBZ3tGQ53t7c6jxw3thY0di7m2n9nsAY-cV5_PmCHDhua516VfaV8Jd_pjxUY4O6g-S14U74XIVnV9eVaUGFsYsvm-KrvnJYPNCIxMoyb-0J3t8BQXfOAvqg7Qoz9K9XUbdfO_6x4QWxp5u9Kfv6ACg7YcJIHBrAHbT1HKTe7Oj70mCzWHTAeOnBv76P5JqsyU_NDhugfl6Ddzq9snokjoNWspqRbbCDCi1kOyL6fbUsvuj-q8OFtT0Q157cY5YfJpt-QoEV2Q5Z2-d_ZHMZ0s

[JimB88]

thanks!

[JUAN EMMANUEL]

I actually love all those big brachs

[JimB88]

Me too! I recently read from The Fossil Book (Fenton & Rich) that when Platystrophia get old they loose their pedicle and sit on the bottom! I'm betting that these died of old age!

[JimB88]

Ok, went back out this Friday morning, left early to avoid the heat, and returned to the cut with the big brachiopods. I checked that cut and the surrounding ones (which all seem to be from the same formation) and did pretty well.

First up is some more of the large brachiopods:

These are Vinlandostrophia ponderosa (Foerste,1909.) The small one in the front is the average I had been finding at my usual stops.

next up, some well preserved strophomenid brachiopods

The bigger one is Rafinesquina ponderosa. I am unsure as to the id on the other one.

Here is a large encrusting sponge

Dermatostroma scabra

And also some nice gastropods as well

Cyclonema mediale

This one needs cleaning , Im hoping its Leptaena but I'll have to use the air eraser on it to find out.

cont....

[JimB88]

After about 45min, I decided to start working my way east, towards home. I was looking for some spots exposing the lower Mississippian Ft. Payne Formation. And I was not disappointed! My fist two stops were 'duds' but the third time was the charm!

I was hoping to find a complete crinoid crown, but, alas the closest I found was this loose partial calyx

Im tentatively calling it Platycrinites but i could be wrong.

The huge stems were everywhere!

This was an awesome find (and I thought those Vinlandostrophia were big!)

Im calling this one Syringothyris for now as its the closest I can find of that age.

Another brachiopod...

This is either Athyris or Reticularia

On the back of the large brachiopod was this little horn coral..

Zaphrentis most likely

By the time I finished checking this small cut it was incredibly hot! So I decided to come home; but, Im definitely planning on returning!

[Auspex]

Jim, I'd love to see you at work; you come up with the neatest things!

[JimB88]

Thanks! You'd see a guy at the side of the road having a problem keeping his pants up (gotta put the fossils somewhere!)

[fossilized6s]

Great finds, Jim. It's like you found a land of giants.

Is there bedrock that you may be able to uncover more complete Crinoids?