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The Alabama fossils are Brooksella alternata from the middle Cambrian Conasauga Formation. There’s some debate about whether or not they’re jellyfish, sponges, or geologic in origin, but personally I lean towards something biological, or at least generated from biological activity.

Having collected many Keokuk geodes, I doubt it to be. Looking into a Brooksella identification, I could not find it to be found in Illinois or Wisconsin. Brooksella seem to be found only in the Cambrian Conasauga Formation of the Coosa River Valley of Alabama and Georgia.

Aldkistocare Sp Conasauga Shale Floyd Co Georgia. M. Cambrian

A little variation today and tomorrow. So many of TFF members have been incredible kind to me over the years and so with keeping to the theme of trilobites, today my thread thanks you . Theses are beautiful and I think it is the contrasting colour of the matrix and trilobites that make them so pleasing to the eye. Aphelaspis brachyphasis Conasauga farm, Murry Country, Georgia Upper Cambrian. @Tidgy's Dad with Sara, @Nimravis and of course Doren.

Most people are familiar with the Conasauga Formation when they think of Georgia's Cambrian record, but the Peach State has a paleontological history dating back several million years before the Conasauga was deposited. Indeed, the oldest fossils in Georgia date back to the early Cambrian, and consist of a diverse form of worms, brachiopods, trilobites, and other creatures such as hyoliths and archaeocyathids. This early Cambrian record is largely divided into three formations, from oldest to youngest the Weisner Formation (part of the Chilhowee Group), the Shady Dolomite, and the Rome Formation. All of these formations, as well as the overlying middle Cambrian rocks of the Conasauga Formation, are well exposed in the Rome and Cartersville areas. Cartersville is a mid-sized town in North Georgia with a rich interconnection between history and geology. Situated near the confluence of three major geological provinces (the Valley and Ridge, the Blue Ridge, and the Piedmont), the Cartersville area was uniquely positioned for the discovery and future development of a variety of mineral resources. Wide scale mining began in the mid-19th century with the establishment of the Etowah Iron Works along the Etowah River. Although the bulk of the works were destroyed by Union forces during the Civil War, mining not only continued in and around Cartersville but actually expanded in the post-war period. Iron was the principal product for a while owing to the region's rich limonite deposits, but by the turn of the century ochre and barite production also became prominent, if not more so. Mining operations peaked by the middle of the 20th century, but some active mines remain in the area, and they continue to be a favorite with mineral and fossil collectors. Thankfully, this past history of mining, combined with the recent construction due to Atlanta's explosive growth, has exposed rocks typically left buried under the thick clay and vegetation of North Georgia. The Shady Dolomite was, and still is, the focus of the brunt of the ochre mining around Cartersville. A carbonate unit, the Shady is easily weathered in North Georgia's humid and rainy climate, dissolving much of the rock and underlaying the ground in a thick, reddish clay. Due to the nature of the weathering, however, distinct beds can sometimes be seen in cuts made into the Shady, as shown in the above photo from a construction site in Cartersville. Another exposure of the red clay residuum made out of weathered material from the Shady Dolomite. Although the carbonates of the Shady are frequently weathered into a thick, red muck, this weathering process typically uncovers a wide variety of rock types that are more resistant to chemical attack, and which would have otherwise been locked into the dolomite. At exposures like the one above, pieces of shale, iron oxides, and chert are common. Alongside the chert are fossils from some of the oldest reef communities in Georgia. This small piece of rock contains fragments of archaeocyathids, ancient sponge-like organisms that once established reefs in the early Cambrian sea. Alongside archaeocyathids, other fossils like trilobites and brachiopods are sometimes found in the Shady, but I didn't find any personally. Aside from iron and ochre, Cartersville was an important center for barite mining around the turn of the century. Most barite mines were located east of town, near the contact between the Valley and Ridge and the Blue Ridge provinces. Although most have been filled in or flooded, one pit that is still left can be seen at Pine Mountain east of town. A few pieces of barite ore line the trail leading up the mountain. A small piece of barite ore from near Cartersville. The walls of a former mining operation near the base of Pine Mountain contrasted with an image of a similar mine when in operation. Leading up the trail at Pine Mountain, one travels across geologic provinces. The valley floor is underlain by rocks of the Shady Dolomite and Rome Formation, part of the Valley and Ridge province, while Pine Mountain itself lies within the Blue Ridge. Climbing up Pine Mountain, you begin to sense that change reflected in the rocks underneath you. The red clay and chert residuum of the Valley and Ridge gives way to brown and white dirt, and the chert and dolomite boulders give way for quartzose sandstones, quartzites, and schists. Along the trail, numerous pieces of quartz sandstone from the Weisner Formation are exposed, and in these boulders you can sometimes catch glimpses of the earliest recorded life in Georgia! The picture here shows a sandstone boulder with a couple of well-worn Skolithos linearis worm burrows. Whereas the Shady Dolomite was deposited in a shallow, tropical sea, the upper Chilhowee Group was deposited in a near-shore environment as indicated by the coarse sediment. That means that 530-550 million years ago, during the early Cambrian, what is now a mountain would have been a warm, sandy beach! And, although they may not seem like much, the humble tubes in the rock illustrate a time when life was not everywhere abundant, and the diverse lifeforms we find at beaches today had yet to appear. Climbing the rocky trail to the summit, one is well-rewarded with a view of the entire Cartersville area, including a view across much of the Piedmont to Kennesaw Mountain beyond, and across much of the Great Valley to the Armuchee Ridges. One can also get a sense of the legacy of intense mining that took place around Cartersville from the many red-colored pits scoured into the nearby hillsides, ghosts of operations past and present. On top of all of that, one can also visualize the impact geology has on the topography of an area. Being the intersection of so many geologic provinces, the Cartersville area is marked by numerous faults, folds, and other complex structural geology that has left pockets of one formation nearly surrounded by pockets of another. This has contributed to the hilly nature around Cartersville, as the comparatively resistant rocks of the Rome Formation and Chilhowee Group forms island-hills in the sea-valleys of the Shady Dolomite. The view from Pine Mountain. The red areas are current and past mines around Emerson, Georgia, just south of Cartersville (which includes the buildings in white). The hills here, which make up part of the Allatoona Mountains, are held up by resistant units like the Chilhowee and Rome while the valleys are underlain by softer carbonates like the Shady. On a clearer day you could make out the Armuchee Ridges lying at the western edge of the Great Valley, a synclinorium of Cambro-Ordovician rocks that stretches from here all of the way to Quebec. I hope you enjoyed the report!

I've had a similar issue, largely due to the constraints of university being a huge time commitment. It's been a few months since I've gotten a good fossil hunt in and I've been itching to get back out there for a while, especially to get my 3rd swing at the new Conasauga fm. site I found out about with the Paleontology Association of Georgia.

It looks like molt fragments from ptychoparid trilobites, probably from the Cambrian aged Conasauga Formation. Pretty cool find!

Aphelaspis brachyphasis from the Late Cambrian Conasauga Formation in Rome, Georgia. Recieved as a gift a few years ago from Monica. Pos. & neg. 17mm. long. This is the last from the Cambrian part of my collection which I can show, since I'm pretty sure that I've already posted all of the others.

Aphelaspis brachyphasis Middle Cambrian Period Conasauga Formation Georgia

Great finds. As to the predicament involving prep, you know the limonite preservation makes these excruciatingly flakey. If it were me, I wouldn't even try to do a top down prep. With the Conasauga, WYSIWYG. Maybe Kris @Ptychodus04 might have a better suggestion.

From the very moment we wrapped up at that Conasauga Formation fossil hunt at the spot I'd never heard of before, I was itching to get back there. I guess that's what going for years without hunting half-billion year old bugs does to you. Well, this past Sunday I had my opportunity to get another bug hunt in. It's a good thing I brought my water boots with me, because the spot was quite a bit wetter than the previous time I had come, with some really large puddles at the foot of the hillside I'd get to work in. After a good while of splitting, I had myself yet another selection of Conasauga trilos Of the specimens I collected this time around, I picked up some really interesting and precarious pieces, most notably this one: If this was all there was to this Aphelaspis plate then it'd be a really nice find, but it wouldn't have controlled my attention in quite the way it would have if it didn't also have this: Apparently when this piece split, it split into 3 pieces, not 2, with the 3rd piece actually being the exoskeleton of the larger individual in the split. How it hasn't broken/crumbled into a million pieces by now is beyond me especially considering how thin it is, though I'm definitely not sure how I want to approach it as a result. I'd love to be able to bring out the rest of the detail in it, but with how fragile I know these exoskeletons to be, I'm not even sure it's possible to do much of anything, at least not with what I have on me. It goes even further too, as on the opposite sides of each of the main 2 pieces, there's another 2 trilobite individuals, one on each plate! The split that keeps on giving, that's how it tends to be with this Conasauga material, even when you're splitting at home! With that collective piece, I think I'll nickname it "Frankenbug". Will definitely be open to ideas on how to approach it! As for the rest of my finds, they may not be quite as remarkable as the piece above, but as per usual you get all your Conasauga Cambrian goodness!

I was wondering if anyone had a good list on different species found in the Conasauga Formation? I've found a few references to trilobites, but I was especially curious about non-trilobite species such as brachiopods, sponges, non-trilobite arhtropods, etc.

And we loop back around to the Cambrian! Here's one of my favorite Aphelaspis brachyphasis hash plates from the Conasauga:

Let's show off pieces of our collections, with a twist: Every person who posts a piece posts one that is 1 geologic time period younger than the last. Example: If a Jurassic crustacean is posted, the next post needs to be something from the Cretaceous, and so on. Starting from the Cambrian going all the way to the Pleistocene (Cenezoic time periods will be divided into the epochs, since they're more commonly referenced), and looping back to the Cambrian after someone posts something from the Pleistocene. Let's see how long we can keep the descending order going! I'll start with a Barrandagnostus inexpectens agnostid plate with other trilo-bits on a Cambrian shale slab from the Conasauga Formation:

Right up there with the Conasauga Shale further north, the Late Eocene Tivola Limestone is a formation that has become one of my absolute favorites to hunt over the course of my visits to the formation. 2 months ago I went there and got a good series of photos and as always good finds, but I neglected to actually post a proper field trip report. It was the first time in a good while that I had gone fossil hunting, something that I had been absolutely craving for a while in the midst of a sea of university exams that lied ahead in the coming month. When we arrived at the always reliable abandoned cement quarry I had one particular idea in my mind for my gameplan; I wanted to see the other side of it. Most of the visits I've paid to this site I'd only really stayed to one side of it while collecting, so I didn't give myself much of a chance to see what the whole of the pit had to offer. I also had the idea to take some photos of the walls of the quarry itself, as you can see the fossilized fauna embedded in the walls just about everywhere you looked, be it the Periarchus pileussinensis sand dollars or the Chalmys spillmani scallops that are so plentiful in these rocks: As is always the case with this formation, I had many nice Periarchus and Chlamys to show for my efforts by the end of my visit, one of which happened to be the first double piece of Periarchus I've found here so far:

Slabs from the Cambrian age Conasauga Shale here in Georgia tend to be really colorful split by split. A lot of that has to do with Iron Oxides present in the rock IIRC. I know that for fossils in general their color is often determined by the mineral environments they get deposited in. These minerals can tell you a decent bit about where certain fossils were deposited (I recall that fossils with a lot of pyrite on them indicates that they were deposited in oxygen-poor environments). This is one of my better (and most colorful) slabs that I picked up at the old Murray county site of the Conasauga years ago. I'm beyond pumped I found another exposure for this.

Awesome finds! Although I only had the chance to visit the Murray County site once, right before it was closed, it too was a favorite of mine. Where else can you find such an abundance of Cambrian trilobites on the East Coast! I am glad to hear that you were able to get back into the groove of things and collect from another exposure of the Conasauga Formation.

If you have ever looked through my post history on this forum over the years, you'd know that the Cambrian age Conasauga Formation has been one of my favorite formations to hunt, being the best formation to hunt for trilobites in the state of Georgia that I know of. Unfortunately for those of us that came to enjoy the abundance of trilobites the formation provided, the main site in Murray county that had become widely known by the time I had visited it a few times had attracted some...shall we say...less than intelligent guests to the area, resulting in the site becoming fenced off. For quite a while now I'd been trying to find another good exposure of the Conasauga to search. While I was able to find mentions of exposures further west in Floyd county in the literature, my scouting trips to see what was there up to this point have been swings and misses. Cue me receiving an email from my local paleo association (Paleontology Association of Georgia for any interested in joining) that we were going on a field trip to hunt for trilobites near the Resaca area. I looked it up, and while I ultimately found one other mention of a separate group going there, I have yet to find literature mentioning the site, and it was quite a bit further south than I was expecting a Conasauga exposure to be (if anyone has said literature, I'm all ears). As you could imagine, I'm pretty excited to learn of a new exposure to a favorite formation of mine. This past saturday, we met up in a gas station parking lot for a quick association meeting and then we were off. It wasn't too long of a drive until we came upon a roadcut that exposed that beautiful Conasauga goodness, an exposure that is much more easily accessible than the Murray site was. It wasn't very long before I spied the first find of the trip: Before too long I had struck a groove with splits in my little corner Here's a montage of what I found over the course of this little expedition. Not the most I've ever picked up from the Conasauga in one go, but it's definitely great to get back into the swing of things with this formation. As for IDs, my prior experience with this formation has me thinking Aphelaspis brachyphasis such as the many pieces I already have in my collection, though this exposure seems to have greater diversity in terms of species when compared to the Murray exposure, and admittedly distinguishing between Aphelaspis and Elrathia antiqua is not my strong suit right now. (I could also use some tips on how to clean some of them up, as some have a bit of gunk on them and I know that they can be pretty fragile)

Hey guys, My name is Renan and I am a geology student out of Atlanta, GA. I often find myself using The Fossil Forum a lot so I figured I would create an account and post on here! I mostly use the forum to find any new fossil spots I haven't been to. I have been to Tibbs Bridge in North GA and found some epic Conasauga Shale trilobites. I have crinoidal limestone from Arkansas. I recently found a fossilized coral in limestone that I still have yet to identify at a Holiday Inn Express in Nashville, TN. I also have some samples of Archimedes bryozoan, crinoids that were given to me by my Paleo professor. I love fossil hunting! My goal is to continue to find more specimens so I plan on posting more on this forum to ask for help on any new finds. Sincerely, Renan

Interesting, that helps a lot. I guess the only question I have from that is if you happen to know if the trilobite zones are also present in the limestone units? I know they're located in different geographic areas, but I was wondering if the Maysville has the same kind of fauna, given it's roughly stratigraphically equivalent to the upper Conasauga in Georgia.

There are other parts with well known fossils. Tibbs Bridge was an example in the Upper, or Mid to Outer Shelf Lagerstatte Unit of the Conasauga (Bolaspidella assemblage zone). The Lower, or Inner Shelf Lagerstatte Unit (Ehmaniella or, for older sources, Oryctocephalus assemblage zone) is also highly fossiliferous. Some Figures from Schwimmer's Publications on the subject of Conasauga stratigraphy and paleontology you might find useful. Relevant Publications discussing the other zones of the Conasauga: Taxonomy and Biostratigraphic Significance of Some Middle Cambrian Trilobites from the Conasauga Formation in Western Georgia Author(s): David R. Schwimmer Source: Journal of Paleontology, Vol. 63, No. 4 (Jul., 1989), pp. 484-494 Stable URL: https://www.jstor.org/stable/1305441 Exceptional Fossil Preservation in the Conasauga Formation, Cambrian, Northwestern Georgia, USA Author(s): David R. Schwimmer and William M. Montante Source: PALAIOS, Vol. 22, No. 4 (Jul., 2007), pp. 360-372 Published by: SEPM Society for Sedimentary Geology Stable URL: https://www.jstor.org/stable/27670429 Glyptagnostus and Associated Trilobites in the United States By Allison Palmer, 1962 also references Conasauga Formation sites from other states but has less of a focus on the stratigraphy and the exact position of the Conasauga beds.

May be a bit of an odd question, but I was wondering what horizons or layers are the most fossiliferous in the Conasauga Formation. I've heard about the Tibbs Bridge site (RIP), but that site exposed a calcareous, light-colored shale from the upper part of the Conasauga. From what I read online it seems that most of the trilobite beds are located in the upper shale layers of the formation, but I was wondering if anyone else knew if the other parts of the formation had anything?

Check the entries below carefully and cast your vote! PM me if you notice any errors with the entries. The poll ends April 9th. Be sure to vote in our other FOTM poll, HERE 1. Fern plate - Carboniferous, Llewellyn Formation - Schuylkill County Pennsylvania 2. Ampullina bulbiformis gastropod - Cretaceous, Grabenbach-formation? - Haspelgraben, Gams near Hieflau, Styria, Austria 3. Colonial coral - Cretaceous, Grabenbach-formation? - Haspelgraben, Gams near Hieflau, Styria, Austria 4. Macrocrinus verneuilianus crinoid calyx - Mississippian, Burlington Formation - Henry County, Missouri 5. Delocrinus vulgatus crinoid calyx - Pennsylvanian, Harpersville Formation - Texas 6. Prehepatus harrisi calappid crab claw - Late Cretaceous Period, Wenonah Formation - Monmouth County, New Jersey 7. Aphelaspis brachyphasis trilobite - Middle Cambrian Period, Conasauga Formation - Murray County, Georgia 8. Romaniceras mexicanum ammonite - Upper Cretaceous (Turonian) - Blue Hill Member, Carlile Shale - Sandoval Co., New Mexico 9. Anataphrus vigilans trilobite - Ordovician, Lower Maquoketa Formation - NE Iowa 10. Coalified (drift)wood - Jurassic, Callovian-Oxfordian (166.1 - 157.3 mya) - The Cotswolds, England, UK 11. Pathological Strombus floridanus gastropod - Upper Pliocene Pinecrest Sand Member of the Tamiami Formation - Sarasota County, Florida

Eugonocare (Olenaspella) separatum Palmer, A.R. 1962 Glyptagnostus and Associated Trilobites in the United States. United States Geological Survey, Professional Paper, 374-F:1-49 PDF LINK figure 4 from: Pratt, B.R. 1992 Trilobites of the Marjuman and Steptoean Stages (Upper Cambrian), Rabbitkettle Formation, Southern Mackenzie Mountains, Northwest Canada. Palaeontographica Canadiana, 9:1-179 figure 8 from: Schwimmer, D.R., Montante, W.M. 2012 An Aphelaspis Zone (Upper Cambrian, Paibian) Trilobite Faunule in the Central Conasauga River Valley, North Georgia, USA. Southeastern Geology, 49(1):31-42 PDF LINK

When splitting some extra matrix from the Tibbs Bridge Road exposure of the Middle Cambrian Conasauga Formation I came across this trilobite cephalon imprint. It does not seem to match any of the common trilobites found at the site and I could not find a similar example in the various trip reports other members have posted about past visits to the site. Any help is greatly appreciated. Thank you!