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A nice Dictyonema flabelliforme dendroid graptolite from Oslo Fields in Norway. It's Tremadoc, Lower Ordovician in age and is thus maybe around 480 mya. Another angle :

Ordovician northeast Arkansas.Found in the same general location.Some show groth lines and a deep cone shaped hole in one end.I am thinking cephalopods or siphuncles?

I am guessing Coral Sponge or Bryozoan I do not know.So I need an ID.Found in creek gravel,Northeast Arkansas,Lower Ordovician.Thanks.

I found these fossils in creek gravel Northeast Arkansas Lower Ordovician.Someone please tell me if they are a sponge or coral.And the name of species .

Hey folks, I was wondering how you guys would approach something like this (or if samples like this are even worth your time!) There's so much going on I'm a little confused as to how and where to start. would you remove the gastropods individually, break the rock apart, sacrifice the broken ones in the search for more complete specimens, leave it as is? I went through the pinned messages and learned a lot, but was curious if anyone's come across similar types of rock and could give some insight. My goal is to hopefully find and extract some of the more complete specimens, and maybe discover some trilobites along the way! The plan was to chisel out as many surface fossils as possible, then strike the rocks with a sledge hammer to break up the pieces, give them a good hard scrubbing, then use my steel picks and chisels to poke around further however the resources provided to me by @FossilDAWG and @Kane (thanks again by the way!) described a number of rare, some now lost, trilobite specices from the same formation found in similar contexts alongside Ceratopea Canadensis, so maybe a lighter touch might be in order? I'm still a little scarred from the time I put a pickaxe right through an almost complete piece of 1st century terra sigillata once upon a dig </3 I'll definitely be looking into air pens/compressors (looking at you ME-9100) as well, but on my pay that's one of those 'somewhere down the line' sorts of purchases. If those are definitely the way to go however, I can always shelve these for that later day...they've been sitting around in a forest for this long, another few months wont hurt! I did notice while cleaning the sample below that there appeared to be two separate matrices, a softer one which I assume was the sand/silt and then the hard dark rock underneath. I've got a much bigger slab with a lot more going on, but I grabbed this little one to practice and learn on! My first target is that crystallized one which is slightly exposed on the top (bottom center of the picture on the right) followed by whatever that is beside it and that mussel looking fellow.

This stone came out of a stream-bed, so no certain provenance; BUT - I'm sitting on the top of the Oneota dolomite, in extreme SE Fillmore County, SE Minnesota. Ever since I moved here, I've found blocky chunks of what I always called quartzite in nearby stream beds; often with ripple marks like this: Sorry about lack of scale, but if you look at the top of the stone, you can see a northern pin oak leaf - it's about 4 inches long. I was told when I arrived that my Oneota dolomite was overlain by the St. Peter sandstone- which has no record of rippled silicified layers. Two years ago, asking among friends on Facebook, I was plugged into 3 different and authoritative geologists, who suggested my stone had to be from the Sioux quartzite- located well north, and had to have been transported by an older glaciation. That quartzite is supposed to be pink when freshly fractured- and I did indeed find some precisely pink stone eventually; verified as the right color. I stick by my "quartzite" rather than "sandstone", and you can see why. However. Several things did not add up, and I kept the ID tentative in my mind. Then I started finding dolomitic marble- not known in the literature, and indicative of some very active silicification episodes locally- which might make quartzite as well as marble. Digging further, I found a few references that say my own bit of Minnesota has the New Richmond sandstone on top of the Oneota dolomite; just locally. And eventually found a reference that in Indiana, there are rippled sandstones from the New Richmond, so highly silicified that "some call them quartzites". That makes more sense from all aspects- the quartzite I find is so abundant it could easily be a layer overlaying my dolomite, and surviving erosion far better, so quite evident. Also- the Sioux quartzite is measured at around 1.2 to almost 2 billion years old - too old for any critter fossils. I have not yet found any fossils in my quartzite - but it's really metamorphosed hard, and some deformation was going on at the time as some strata are curved; in the Oneota it's strictly flat. The New Richmond is still classified as "lower Ordovician"; somewhere around 450 MYA, I think. There were critters. This next image is the right upper corner of the rippled stone, rotated for a different perspective: Next; same stone; rotated right so you don't have to break your neck looking: and last the same only with "definition" and "sharpness" enhanced as far as I can with my cheapo software. The photo of the entire stone shows you that the rest of the ripples show no disturbances at all; it's only this corner; which looks just a bit like - feet? Hopping along, then 'taking flight"? or if going the other way, landing, causing that different mark? Also note; the "entire stone" photo is of the stone slightly wet; changing some visible details. I have these same photos at about 6 megabytes each, if that might help at some point, and of course I have the stone if you have suggestions for improved images. What do you all think; is there any chance this is actually a trackway- that should perhaps be shown to the real expert folk? I just can't quite dismiss it; there are several aspects that repeat regularly... Theoretically, SE Minnesota was mostly marine tidal flats at this point- the source of the ripples. I eagerly await your thoughts.

This rather tasty, large graptolite just arrived after a surprise auction win. It's labelled Clonograptus rigidus Hall which seems reasonable though I'm always being caught out by these. The location is given as 25km north of Zagora (should be OK?) but the age is given as Floian stage when I'm pretty sure it should be Tremadocian, probably Murrayi Zone. ( @Spongy Joe - I guess you've seen a lot like this... )

I found a prickly ball with an asymmetrical star and a raised rim on the top, a flattened bottom, and what looks like a short stalk. It measures 68 mm across including the stalk, 48 mm tall, and it is missing parts of its edge and side. Inside it is a pale beige chert. The exterior is very finely ornamented and covered with tiny angular holes that are making my camera pixelate. I have done my best to capture the fine detail, There are also some tiny pyrite ooids in the deeper areas on the face and on the bottom. The stalk feature is encrusted in bright white lime, and has resisted all attempts to photograph it. It is the piece that sticks out at the top of the pics. It is located at the same level as the lower edge and is 14mm in diameter and appx. 8 mm in length. It is segmented like an orange in cross section. As viewed from the top, the star face is mostly complete. The left arm of the star is broken away, and the rim is missing at the broken edges at bottom and right side. Thanks for looking!