Hi Folks,
When it gets too hot in the great western desert, we go fossil hunting in the great Rocky Mts (about 105F in the valley and about 75F on the mountain). This spot is in the Wasatch Range, I find fossil cephalopod molds (first picture) right at the place this picture was taken(second picture).

After a few hours hunting I decided to do my Croc Hunter impression, that's why the third picture is blurry.

I fill the molds I find with liquid latex to get a cast of the shell. The nice thing about liquid latex is it has .6% ammonia added as a drying agent, so I can imagine myself working alongside Steve and Kat while they are playing with a big squid.

:ammonite:

As Steve Irwin would say, "Crikey mate! Ripper!" Kevin, you are the 'Ammonite Hunter'.

That rattlesnake is a very impressive. I'm not surprised the picture is a bit blurry; you've got steadier nerves than me! I think I would have cleared off like lightning. How large was it? How close did you get? And that scenery looks beautiful.

I've managed to find out a little bit of information about Eumorphoceras. This cephalopod is known from both North America and Europe, especially the Texas Barnett formation and examples are known from Yorkshire in the UK. Actually, Europe and North America were very close at this point in time and were actually converging to form part of the later supercontinent Pangea. This goniatite would have inhabited part of the south-west Paleo-Tethys ocean, an area that was diminishing in size.

This animal existed for about 19 million years from 342-323milion years ago which places it in the early to mid Carboniferous period. It has a very discoid shape with thick whorls and a simple suture. This goniatite, (subfamily: Dimorphoceratacea, family Girtyoceratidea) is usually preserved in aragonite.

If anyone is interested in how the surface of the earth has changed via continental drift and wondered where land masses were located in relation to each other at any point in time, this is the place to go:

Paleomap Project (http://www.scotese.com/Default.htm)

Fascinating stuff!

The nice thing about liquid latex is it has .6% ammonia added as a drying agent, so I can imagine myself working alongside Steve and Kat while they are playing with a big squid.
:lol:

I think I would have cleared off like lightning.
Right on, that snake looks ready to pounce!

Phil, that link is great -- it even shows outlines for the US states to show where they were way back when! Hard to tell which is which after a while, since they themselves obviously went through land changes as well.

Great pictures Architeuthoceras, thanks!

The little cutey was only about 2 feet (60cm) long. There were three of us surrounding the snake, but, for some reason it kept coming towards me, maybe it could sense something, seeing me stooped over trying to take a picture, walking backwards about to trip over a fallen tree. This is only the third rattler I have run across, and the first time I have had a camera with me to take a picture.

That is some great information on Eumorphoceras Phil, heres some more:

Emorphoceras girtyi Elias 1956, is an index fossil for the middle Arnsbergian stage (Early Carboniferous or Late Mississippian). That means as you work your way up thru rock strata, the first appearance of E. girtyi marks the rocks of Middle Arnsbergian age. Higher up in the rock strata another form of ammonoid will take the place of E. girtyi. E. bisulcatum is the next Eumorphoceras in line but is not used as an index fossil for a variety of reasons, so another form is used, in the Western US this would be Cravenoceratoides nititoides which, like E. bisulcatum, is also found in the UK, so the two areas can be correlated and the rocks dated. This process is used to create biozones, so rocks from all over the world can be correlated and dated.
Rocks of this age in the UK provide a higher resolution for zonation than most other areas, so some are proposing to make those rocks a Global Stratotype, or a place where all other rock strata can be refered to. See Riley, N.J. et. al., 1994, Geochronometry and geochemistry of the European mid-Carboniferous boundary global stratotype proposal, Stonehead Beck, North Yorkshire, UK: Annales de la Societe Geologique de Belgique, v. 116 p. 275-289.
The following picture file of a correlation chart showing where E. girtyi fits into things comes from Titus, A. L., 2000, Late Mississippian (Arnsbergian Stage E2 Chronozone) Ammonoid Paleontology and Biostratigraphy of the Antler Foreland Basin, California, Nevada, Utah, UGS Bull. 131
:ammonite:

Wow! Thanks for the detail.

I had no idea that UK rocks are potentially to be used as a form of baseline in global stratigraphy. Is this because lowland UK has had a very turbulent geological history, with many periods of flooding by shallow seas? Zonation must be very well defined, I suppose.

Do you by any chance have a similar chart for the Albian in the early Cretaceous? I'd be quite curious to see this as most of the ammonites I find are datable to 100mya and are mostly Hoplites and other members of the Hoplitidae.

Cheers as ever!

Got out in the desert yesterday and thought I would post a couple of pics just to show how things went.

The Ammonoid is Girtyoceras meslerianum, about 327my old. From a concretion that contained a few other ammonoids. The formation it was found in is the Lower Carboniferous (Upper Mississippian) Chainman Shale, it lies just above the Joana Limestone, which is pictured with my truck in the photo below.

Also caught this pic of a blue bird as I got close to it's nest, never did see the nest, but the bird wouldnt leave me alone. :grin:

Spectacular pictures as always Kevin. That's a very striking bird, any idea what it is?

The Bird is a Blue Bird, or Mountain Blue Bird, Sialia currucoides.

Another Girtyoceras, but this one retains some of the shell. And also a bus for scale (the space took up by the pixel used for the dot is probably about 10x the actual size of the fossil :wink:)

Tiny-weenie-itsy-bitsy speck of a fossil.

Ha ha! Great picture there Kevin. That really puts the fossil into perspective!

Those growth lines are really well preserved; have any conclusions been drawn as to how long goniaties may have lived based on examinations of these features?

have any conclusions been drawn as to how long goniaties may have lived based on examinations of these features?
Ive been looking for something Phil, no luck. Studies have been done on Nautilus, and judging from some of the repaired shells of other ammonoids on the ammonoid pathology thread, i would have to think that it didnt take very long for an ammonoid to grow a shell. The baby snails in my garden are full grown by the end of summer. I dont know if ammonoids would have lived as long as nautiloids, or grew shells as fast as snails, but I imagine they would be mature within a year and live for at least two years, some of the larger ones living longer (no proof or evidence, just speculation :wink: ) I'll keep looking.

Thanks very much for checking for me Kevin. This is just a thought but perhaps if ammonoids generally lived nearer the surface in warmer waters with more sunlight than the deep water Nautilus, perhaps their metabolism worked at a faster rate? Perhaps then their growth rate would be faster and average lifespan would be shorter than Nautilus? Perhaps also the early orthocone nautiloids grew much quicker than Nautilus as they also tended to live in shallower water and inhabited a greater variety of habitats in varied forms.

I'm sure I read once that ammonoid lifespan has been estimated at anywhee between 4-36 years but I can't find the reference right now. I will report back if I can find it.

Thanks as ever!

RIGHT UNDER MY NOSE :oops:

Bucher, H., J. Guex, N. H. Landman, and S. M. Klofak. 1996. Mode and rate of growth in ammonoids. in Landman, N. H., K. Tanabe, and R. A Davis (eds.), Ammonoid Paleobiology, Plenum Press, New York, pp. 408-463.

A summary

Time to reach maturity (from several studies)

Periodicity of ornamentation
1-20 years avg. 5
Seasonality (septal spacing)
1-7 years
Size classes
5-6 years
Epizoans
1-7.5 years

Water Depth

Shallow @ 5 years
Deep @ 10-15 years

Length of life after maturity

Shallow water forms: possibly semelparous died after reaching maturity and mating
Deep water forms: iteroparous possibly mated several times and lived several years after.

It finally cooled off enough I could get out and look for some fossils. Found this Forresteria alluaudi in a large concretion. The first pic shows it as found in the concretion, the phragmocone was filled with calcite that had started to crumble so I had to soak it with super-glue. The second pic shows the fossil after preparation. You can see the last chamber and the last suture. The third pic is just a view showing the side that was exposed.

Some other fossils from the same concretion. Alot of Baculites mariasensis in the first pic. A bivalve (Inoceramus) in the second. And a view showing the concretion atop the teepee butte that formed around it.

Very nice prep job Kevin.

Just how old is this ammonoid?

Forresteria alluaudi is an index fossil for the Middle Coniacian (Late Cretaceous) F. alluaudi Zone, aka Scaphites preventricosus Zone, about 88.5mya. In Europe it may be refered to the Peroniceras tridorsatum Zone.
This is another one of those "Polymorphic" forms having about 10 different genera, sub-genera and species as synonyms. The fossil shown was first described as Barroisiceras (Forresteria) forresteri, it is the more robust and strongly ornamented form, Barroisiceras (Alstadnites) sevierense was described as a medial form, and Barroisiceras (Harleites) castellense was descibed as the compressed, feebly ornamented form. It keeps me wondering why the Cardiocerids and Hoplitids are not lumped together into a single taxon, are there just more specimens to study or more studiers to the specimens, are the lumpers and splitters lumping and splitting 8-)

Collignoniceras woollgari regulare, Turonian, Late Cretaceous. At the bottom of scour troughs filled with silt.

Lusitanoceras granosum found last weekend, no need for any prep work on this one, just a quick brush up. From the Brigantian faunal stage (Late Mississippian/Early Carboniferous) about 328mya. One of the largest goniatites I have ever found :smile:

The second pic is a large crushed one, I dont know if it will last as it is crumbling and just seems to dissolve when I apply vinac. :hmm:

The third pic is a close-up of the shell of the first fossil. The lirae seem to have been abraided slightly but the growth lines are well preserved. And there are those small pits again, could they be sponge attachment scars?

I really don't know what to say other than what stunning finds Kevin.

Are those possible 'sponge attachment scars' on both sides or just on one? I'm just trying to imagine the empty shell lying on the seafloor, I suppose if the shell was colonised, growth would largely be on the upper surface.

Hi Kevin

Yes, great finds. Nice ornamentation on the Lusitanoceras granosum :smile:

Andy

On this fossil they are just on one side but some of the others I have, have them all around, some surfaces having more pits than others.

I think these are the culprit, boring sponges (http://www.vattenkikaren.gu.se/fakta/arter/spongiar/clionida/clioe.html)

There's nowt worse than a boring sponge - you go down the pub for a quiet drink and then along comes this sponge 'did I ever tell you about the time I was sitting on a reef blah blah blah' it starts and you know your stuck there for the rest of the night having to listen to it drone on. :lol:

Sorry. :roll:

There's nowt worse than a boring sponge - you go down the pub for a quiet drink and then along comes this sponge 'did I ever tell you about the time I was sitting on a reef blah blah blah' it starts and you know your stuck there for the rest of the night having to listen to it drone on. :lol:

Sorry. :roll:


:tomato:

I found these yesterday, a couple of fair Prionocyclus macombi from the Mancos Shale in East Central Utah.

8-) Kevin !
yesterday founds several ammonites from Bathonian exposure, round as tennis balls not in my local geo guide ! Will take pics & post soonest

Keef

Stunning Kevin. Were these just lying on the surface like that, or did you have to dig for them?

Look forward to seeing Spartacus's rocky balls too.

Phil,

The first one was partially exposed so I just had to pull it out of the ground (in 2 pieces). The other one was picked up in several pieces and repositioned for the camera. I collected as many parts as I could find but don't know if the inner whorls were even preserved.


And about Keefs rocky balls....:silenced:

Look forward to seeing Spartacus's rocky balls too.

ooh, you are cheeky !:heart:

Keef

Look forward to seeing Spartacus's rocky balls too.

OOOOOOOOOOOOOOOOO.............:shock: Me too. :wink:

Found this Forresteria alluaudi in a large concretion.

Your finds are very interesting Kevin.

I collect similar ammonites in the (assumed) Lower Coniacian of France. All of them are most likely to be Forresteria (Harleites) petrocoriensis, and they include flat and robust morphotypes.

The scenery is not as impressive as in Utah, but nice anyway :wink:

http://img463.imageshack.us/img463/5591/pict00141ab.jpg (http://imageshack.us)

http://img159.imageshack.us/img159/5755/pict0177cp6.th.jpg (http://img159.imageshack.us/my.php?image=pict0177cp6.jpg) http://img235.imageshack.us/img235/491/pict0178lu8.th.jpg (http://img235.imageshack.us/my.php?image=pict0178lu8.jpg) http://img235.imageshack.us/img235/9127/pict0179tv1.th.jpg (http://img235.imageshack.us/my.php?image=pict0179tv1.jpg) http://img450.imageshack.us/img450/853/pict0180du4.th.jpg (http://img450.imageshack.us/my.php?image=pict0180du4.jpg)

First, let me say :welcome: to TONMO Polyopsis

According to the latest time scale and zones for the late cretaceous (http://norges.uio.no/timescale/Fig18.1_Cret_colA.pdf), F. (H.) petrocoriensis is early coniacian (? is that wrong), just below the tridorsatum zone where those I find (http://www.ammonoid.com/coniacian.htm) come from. Looks like you find some very interesting ammonites, most of the F. alluadi I get are the robust morphotype, yours seem to be the flat type, or is that just the way Harleites is. Thanks for posting pictures of your fossils.

The scenery looks beautiful over there, looks like you have some shade once in a while unlike over here. :grin:

First, let me say :welcome: to TONMO Polyopsis

According to the latest time scale and zones for the late cretaceous (http://norges.uio.no/timescale/Fig18.1_Cret_colA.pdf), F. (H.) petrocoriensis is early coniacian (? is that wrong), just below the tridorsatum zone where those I find (http://www.ammonoid.com/coniacian.htm) come from. Looks like you find some very interesting ammonites, most of the F. alluadi I get are the robust morphotype, yours seem to be the flat type, or is that just the way Harleites is. Thanks for posting pictures of your fossils.

The scenery looks beautiful over there, looks like you have some shade once in a while unlike over here. :grin:

Hi Kevin, thanks for welcoming a new member from overseas :grin:

It is right that standard ammonoid biozonation considers H. petrocoriensis and the likes lower Coniacian. However, recent work on inoceramids + the Turonian-Coniacian succession in Madagascar + others suggest that these faunas could be partly Turonian. This will be the topic of my PhD thesis :wink:

You're right, most of my Harleites are quite flat compared to F. alluaudi (nice specimens by the way !). The latter is very rare in France.

Yes, the scenery is nice but the temperature can also get very high in the summer. I took the pic last spring.

Bonjour Polyopsis ! I'm in French France too but am an English interloper !
(sorry about the delay in posting pics but I'm old & slow, my eyes are dim, my bones are bent, my hair is grey etc. etc.)

Keef

My brother Duane and I went out looking yesterday and found a couple of small Placenticeras syrtale. This one ended up being left as the inner whorls were crushed and the overlying rock turned out to be very hard. Still a nice specimen :smile:

This one is the first i've took home in quite a while. :grin:

Placenticeras syrtale, Middle Santonian (Late Cretaceous)

Wow.

I would love to stumble across something like that. I was helping a friend fill in a large hole in another friends yard down here in Texas. They had removed their septic tank, and while tossing dirt/rock back into the hole I came across a few tiny bivalve fossils mixed in the rock. Made me want to sift through the rest of the soil before we put it back in the hole.

Nice ammonites! Are they rarely found intact? Is there much else to be found in that area - bivalves etc?

Andy

Most of the ammonites have crushed inner whorls, the weight of the sediment prior to fossilization crushed the hollow phragmocone, while the living chamber got filled with sediment and was un-crushed. Only those that were broken and filled with sediment prior to sediment compaction get fossilized complete.

The most common macro fossil in these beds are the bivalve Inoceramus, some concretions filled with them (unfortunately no pics:oops:[a big one back on this (http://www.tonmo.com/forums/showthread.php?t=4896) thread]). This gastropod was found the other day, and this bivalve was found a few years ago in the same beds. I havent identified either one yet.

Congratulations on yet more spectacular finds Kevin. For interest, here is a nice artist's reconstruction of Placenticeras catching fish. Not convinced by the tentacles, but a nice drawing nonetheless:

http://www.dinohunter.info/html/art.htm

Well done again on those finds.

Found this a couple of weeks ago. A very nice example of Lusitanites subcircularis a Carboniferous (Late Mississippian [Brigantian]) goniatite. This is the largest I have found of this species, a little over 24mm, almost an inch dia. And one of the best preserved.

WOW :shock: that's gorgeous!

J

WOW :shock: that's gorgeous!

J

I concur. The grooves are beautiful! So symmetrical and regular. Amazing craftsmanship!

Cheers!

Oh that really is a stunning find. Do you have any interesting snippets about Lusitanites you could kindly share? Is this fully grown do you think? Come to think of it, did goniates display sexual dimorphism as did some of the later ammonoid families?

Great find Kevin, well done indeed.

:shock: wow, what amazing detail! Thanks for sharing with us.

Oh that really is a stunning find. Do you have any interesting snippets about Lusitanites you could kindly share? Is this fully grown do you think? Come to think of it, did goniates display sexual dimorphism as did some of the later ammonoid families?

I just re-measured it, 22mm, the micrometer scale in my eyeball must need re-calibration. :wink: No interesting snippets for this one at the moment Phil. The sutures end right at the aperture so the body chamber is the complete last whorl, I cant tell if there was more that has broken off or not. The last few sutures (you can barely see them on the earlier whorl, right at the aperture) seem to be closer together than the earlier ones so maybe this is an adult (when ammonoids approached maturity their growth slowed so the last few sutures were formed closer together than the earlier ones). Alot of goniatites were small, they average about 20-30mm dia. I dont think there was near as much dimorphism in the Carboniferous as there was later, at least not in the shells I have found.

I found these yesterday, the body chamber and part of the phragmocone of a Jurassic (Oxfordian) ammonite Goliathiceras (Pachycardioceras) sp. Shown kinda put back together and as a bunch of pieces on the ground, the small portion of septate whorls actually fits in one of the body chamber molds.

Also from the same place a bunch of Belemnite guards, these are from Pachyteuthis densus.

I had the great pleasure of spending a few days collecting with Dr's Alan Titus and Dieter Korn in Western Utah and Eastern Nevada a few weeks ago. I just wish I would have taken more pics, here are a few I took.

The top left pic is of a layer of limestone filled with goniatitids.
The top right pic is a few nice fossils Dieter found, the large one is a Goniatites and the other is a Girtyocerid. (they are in the process of writing these up so I will hold any specific IDs)
btm. left pic, Dieter Korn on the Left and Alan Titus on the right, the House Range in the background.
last pic is a Goniatites I found.

I really learned alot from these guys and had a great time. The main difference between pro and avocational (besides knowledge) is the size of their backpacks, mine was very small:oops:

By the way, I have been working in Wyoming with limited internet access the last few weeks and will be there for a few more weeks so I may not be posting two much (if it is at all noticeable).

I visited an outcrop of the Jurassic Redwater Member of the Stump Formation and found these. I have been drooling over this outcrop all summer on Google Earth and decided to stop off on the way back from Big Wonderful Wy. this weekend.

Cardioceras hyatti from the C. cordatum zone. The bottom photo shows them as found and the top two show them after being subjected to my preparation skills. Notice also the small marine reptile vert. on the right of the bottom pic. from the same concretion.