When Ammonites Fly

Along the lines of reverting to aquatic dinosaurs as has been seen in the geoblogosphere of late, I give you Duria Antiquior (above), and it's lithographic byproduct (below).  Floating on the surface of the water are ammonites with wings (or sails as conjectured some).

Clearly showing that ammonites could fly

 

Or could they?


A lot of science has been done since the art above was first seen.  Back then about the only creature known to compare the ammonites to was the Argonaut, one of the group of octopus that are known for a lot of webbing between their arms (such as this Blanket Octopus).  The "wings" of argonauts are specially modified arms used to secrete a calcium carbonate shell used to hold eggs (best seen in the top photo here).  We now compare ammonite shells more closely to the Pearly Nautilus and the animal itself to the ten armed cephalopods.  Hopefully we can advance as we learn, .

The Museum in Green River, Utah

 The Mancos Shale exhibit at the John Wesley Powell River History Museum in Green River Utah, is now open.  Along with a couple of dinosaurs and other murals, it is a very nice addition to the museum.  In the distance on the right you can see the ammonite I found and posted about back in this post, and after it was prepared in this post.

 

Here is a view of the specimen with the mural behind it.

  And the sign telling about the collection and preparation. 

And a few of the other ammonites I donated (the six on the left).  And more of the large mural behind it, unfortunately showing a wounded scaphite, or is that just the leftovers of a large marine reptile it just finished eating. ;)

For a cold, snowy, December day

San Rafael River cutting through the Swell

Just to remember those hot days of summer and early fall in the desert.  The Sinbad Formation of the Thaynes Group slopes down to river level on the left, bleached rocks of the Moenkopi Group up to the maroon Chinle Formation on the slopes of Assembly Hall Peak, with a cap of Wingate Sandstone, and Kayenta and Navajo above that on the cliffs beyond.  The leaves of the Fremont Cottonwoods just starting to foretell the cold and snow of today.

Of Cephalopods and Sponges

Early Ordovician orthoconic nautiloids in a sponge/algal deposit, back when life was just beginning to diversify.

 

Early Triassic ammonoids in a sponge/microbial deposit, back when life was beginning to re-diversify.  Just after the Permian-Triassic mass extinction.

Silica Replacement

An update for this old Calcite Replacement post.

 After finding another small ammonoid (above) in the same beds, and a discussion on TONMO, I've realized the pattern on the two fossils is that of "Beekite".  Not having a lot of experience with silicified cephalopod fossils around here, I got out the acid bottle, fizz on the matrix, no fizz on the fossil.  So instead of a Calcite replacement, they are replaced with Silica.  Beekite may be a mineral, but the word is more commonly used as a descriptive term for the concentric rings of the replacement material.  

The fossil from the first post showing the "Beekite Rings".

The First Utah Cephalopod Fossil

Title Page

Although fossil cephalopods had probably been collected by the Native Americans, fur trappers and early Immigrants for years, the 1859 Simpson Survey was one of the first scientific expeditions that collected fossils, and probably the first to collect cephalopods and have the results published.  Mr. Henry Englemann "the zealous geologist of the party", collected what is to my determination, the first fossil cephalopod to be mentioned in the scientific literature from what is now the State of Utah.   Englemanns's fossils were described and/or listed by F. B. Meek in: Appendix J., Report on the Palaeontological Collections of the Survey (p. 339-373 pls. I-V).

page 371

On page 371, in the list of Lower Carboniferous Forms, appears; Nautilus ____, undt. sp., No. 201.  It was not figured, only listed.  The given coordinates puts it just south of Fivemile Pass, a few miles west of Fairfield, a place I collected many brachiopods as a kid.  The Mississippian Manning Cyn. Shale and Great Blue Limestone both crop out in that area, so one of those formations is probably the provenance.

Though this report was completed before the Civil War, it was not printed by the government until 1876 because of it.

Unexpected ammonoid

Churkites cf. C. noblei

An internal mold of the body chamber, much like the first photo in THIS old post.  This fossil means some of the beds I was collecting in are older than I thought or this ammonoid ranged into younger rocks.  Only more collecting will determine how it fits in the column.

Payday for an Amateur Paleontologist

From the Merriam-Webster Dictionary "Amateur: one who engages in a pursuit, study, science, or sport as a pastime rather than as a profession".  It don't say anything about getting paid, just about having fun or making a job out of it.  I guess that one of the greatest means of compensation someone that does this for fun can receive, and retain an amateur standing, is to have a fossil named after them.  Well, I got paid.

 

 Kazakhoceras bylundi

It don't pay the mortgage or put food on the table, but that doesn't matter, that would be like getting paid to go to the amusement park.  Just the privilege of going out in the field with Dieter and Alan, spending a few days having fun, collecting and discussing the fossils, was compensation enough.

Thanks again Dieter and Alan!

KORN, D. & TITUS, A.L. 2011. Goniatites Zone (middle Mississippian) ammonoids of the Antler Foreland Basin (Nevada, Utah). Bulletin of Geosciences 86(1), 107–196 (60 figures, 37 tables, appendix). Czech Geological Survey, Prague.