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A very odd rock found by my wife in Arizona as a child. Exact locality unknown. Lots of textures. There are some pretty long crystals in the cavities. Could this be a geodized fossil? If so, what kind? It doesn’t really look like pictures of geodized cephalopods or crinoids. Thanks!

So I got the footprints out of the wash before the monsoon arrives. Still haven’t figured out what the little prints are from. Anyone have info? Lots of nice chirotherium prints.

Hello! I am wondering about a couple of fossils found in Yavapai County, Arizona, approximately 30km south of Ashfork, Arizona. I chose this canyon to explore because on another website I saw mention of Arthrodire plates having been found in a quarry here. That site listed those plates being found in the Devonian Martin Formation. Well, after some research I figured out that the quarry was associated with Drake Cement Plant, which is perched on the edge of a canyon called Limestone Canyon. So off to the canyon my son and I went. This canyon had several distinctly different limestone layers, but the deepest layer, exposed on the canyon floor, had a variety of these (most pics taken in the field). Most were in large slabs of rock, but we found a couple smaller pieces that we brought home. We are dissolving one in Muriatic Acid out of curiosity, and it is revealing a "ring" of fossilized material. Can anyone tell me what these are? My son is quite curious to know. Thank you for any help!

ARIZONA FOSSIL ADVENTURES By Chris Schur Exploring the Winkelman Red Brachiopod Site. On Highway 77, one mile north from the turnoff to Winkleman is one of the most awe inspiring scenes to be found in Arizona. Here, the road cuts through a vaulted limestone canyon hundreds of feet deep, with the multihued layers clearly visible. At this location lies an old quarry on the north side of the road which cuts right into the Paleozoic Naco limestone cliffs. This February, we visited this site with some paleo friends to examine the fauna present and determine the suitability for future outings. We found that large boulders of limestone littered the bottom of the old abandoned quarry, which were once part of the surrounding cliffs. A hundred feet or so into the man made canyon, the limestone boulders contain bright red chertized fossil casts of several types of brachiopods, crinoids and bryozoans. Also present everywhere are worm burrow trace fossils, found in a spectacular violet hued limestone matrix. Description of fauna present: Brachiopods. Two types of marine brachiopods are abundantly preserved in red chert. The first type, a small Spirifer ranges in size from less than a quarter of an inch upwards to over an inch. This is by far the most desirable, but less common of the two brachs seen here and are usually preserved as complete three dimensional casts with limestone filled centers. The second and far more common is an unidentified rounder heart shaped brachiopod. With sizes ranging from one half to two inches in diameter, including many large and fragmented shell pieces. The wall is thin, and the center also filled with limestone, so one must be careful in using acid to extract the delicate red or pink chert specimens, or they will fall apart. Crinoids. This site contains some of the largest crinoid stems I've ever seen. While most are 3/8 of an inch in diameter, we found many much larger. The really big ones were nearly an inch in diameter, with a small rounded five point star shaped central canal. Countless smaller stems are seen as well, forming much of the grey colored limestone matrix itself, often referred to as "crinoidal limestone". Some of the largest ones however were preserved in red chert, and several one to three inch long specimens were retrived. Bryozoans. Two types of "moss animals" were found here. The common net like Fenestrellina types were abundant, filling in the spaces in the limestone matrix with mostly small fragments. The second, and much more common type was a small branched animal, usually preserved as a black film on many of the loose limestone boulders in the bottom of the canyon. Trace Fossils. On the visible surfaces of many of the large boulders in the bottom of the canyon are the trace remains of hundreds of channels and tunnels in the fossilized ocean bottom from burrowing invertebrates typical of mid to late Paleozoic time periods. On many of the exposed surfaces of the limestone, we can see one to two inch diameter trails where the animal tunneled through the muddy bottom crossing and passing through the tunnels of others as well. Often we see and entire block of violet hued limestone with burrows passing through the stone, filled in with white limey sediment, layer upon layer as the sea bottom slowly filled in with more mud. Cross sections of the burrows are oval in shape, and typically an inch tall, and 1 1/2 inches wide. As for a possible animal that formed the burrows, the fossil record here does not preserve any mollusk or crustacean large enough to have made them, indicating that either it was a soft bodied animal that did not fossilize or a crustacean whose chitinous outer exoskeleton that dissolved or fell apart soon after death and prevented fossilization as well. A useful observation is that within the violet limestone matrix containing the burrows, we find many of the red chertized brachiopods intermixed. This indicates that the red brachs coexisted with the burrowing animals and shared a common ecosystem. Extraction of the Fossils. When you visit this site, be prepared to do a bit of hard rock quarrying to remove the good specimens. Because this site has been known for years, don't expect to pick up small pieces of limestone matrix and have them filled with choice specimens! The best specimens will have to be removed with hammer and chisel from the large limestone blocks. We have found that a standard geological pick is not enough to extract the material. The best tool is a heavy duty 1/2 to 1 inch diameter masonry cold chisel and a heavy hand sledge. Also mandatory will be a good pair of safety glasses to deflect flying shards of matrix, and a pair of work gloves to protect your hands. Remove the prospective fossil by chiseling a deep channel around it, keeping at least an inch away from the delicate red chert. When the channel is at least an inch deep, you can pop it off with one swift blow, or work around the base with a smaller chisel. Once the specimen and surrounding matrix is removed, the fossil can either be displayed as is, or removed from the matrix. While mechanical preparation works well here, some success with smaller specimens can be had by dissolving the limestone with acid. For most small pieces, vinegar works well, remove only the outside material but do not leave in too long because many of the larger brachiopods are filled in the center with limestone which helps support the fragile shell material. Muriatic acid that has been diluted with water works faster, but should only be used under adult supervision. The large crinoid stems come out particularly well with the acid treatment, leaving a hollow center in the stems. Further explorations. We have not been further up the canyon, however there is no doubt that the best and freshest specimens will lie in the rugged cliffs beyond the collection site. While such a hike should not be attempted by the inexperienced, prepared fossil hunters may uncover a rich bounty of more red chertized fossils in the walls beyond. The Pennsylvanian Naco limestone contains in other parts of the state some of the best brachiopod fossils to be had, along with plentiful bryozoans and other interesting marine invertebrates. Other layers of limestone contain no apparent fossils at all. But it is the lure of the ancient sediments that push the fossil hunter onward, always hopeful that next discovery could be just around the corner! For furthur reading on this spectacular area, refer to USGS Bullitin 176 highway road log by Wess Pierce. I wish to thank Tom McGarvin of the Geological Survey office in Tucson for helping with the identification of the sites age.

I took my first long trip (more than 15 minutes) to search for Permian fossils in the Kaibab Limestone of central Arizona near Pine. I have previously only collected silicified fossils that had been transported south of the Mogollon Rim by streams. The Kaibab is known for two silicified fossils that are great index fossils for the Leonardian (Kungarian) Age across western US: Peniculauris bassi, a brachiopod and Actinocoelia maeadrina, a sponge. At first I was disappointed because I have heard that you could collect hundreds of each type in a short period of time. However I found a couple of sponges with the best 3 D texture that I have seen on the internet. They each are each about 13 cm in length. I will take quality over quantity any day. The Peniculauris bassi brachiopod is about 5 cm wide. I also found some very detailed echinoid spines (3.5 cm field of view). I will have to go back to the top of the Rim to collect more types of fossils. I only have a few hundred square miles of Kaibab to search, exclude that near the Grand Canyon. Good reference on Actinicoelia maeadrina: Griffin LR (1966) Actinocoelia maeandrina Finks, from the Kaibab Limestone of northern Arizona. Brigham Young Univ Geol Stud 13: 105–108 http://geology.byu.edu/home/sites/default/files/actinocoelia-maeandrina-finks-from-the-kaibab-limestone-of-northern-arizona-leland-r.-

I found this and initially thought it was uniquely shaped petrified wood. We have found a lot of petrified wood in the same spot. However, all of the wood that I have found has some evidence of tree rings in the cross section. This does not. The "bottom" or blunt end, looks more like worn bone to my untrained eye. I know that identifying what kind of bone will be impossible, but I am just looking for confirmation that it is indeed bone, and not petrified wood, or just a strange mineral structure in rock. It was found near the Little Colorado River, near Gray Mountain, Arizona, which is about 45 mins north of Flagstaff, AZ. It was found on the surface. We have found what we believe are coprolites with very well preserved seeds in the same exact spot. Thank you for any help!

Hello! My name is Natalie and I am a new member living in Flagstaff, Arizona. I have always been interested in fossils and fossil hunting, but growing up on an isolated island in Alaska did not lend itself to many finds. The geology around Ketchikan, Alaska (the Southeast panhandle of Alaska) is very young. I know of a few ice age fossils found in caves, and some shells, but that is about it. I moved to Arizona years ago, but have just now gotten into rock hounding. And while rock hounding my partner and I have started to find some fossils as well! I am excited to learn from this website. And if there are other Arizonans who might like to organize fossil hunting trips, I would be interested in teaming up. I plan to post a few pictures of some unidentified fossils in the hopes that the experienced members here can help me out. Thank you! Natalie

Hello, I found this rock this morning behind my house and I'm drawing a blank as to what it could be. There are lots of brachiopods, bivalves and gastropods in this particular area but nothing that matches this. It kinda looks like an end view of a coral but I only find those about a mile away and not preserved like this. Any ideas would be appreciated. Thanks for looking. Northern Arizona, Mississippian, Redwall Limestone, Mooney Member.

This is a piece about 2 inches wide. It is Carboniferous limestone in Northern AZ, but I do not recognize the branched, leafy fossil. Any help?

My first attempt here. I'm having a great time exploring the Mogollon Rim area near our home here in Arizona. The Kohl's Ranch area near Payson is famous for its Carboniferous brachiopods, but I have a piece that has obvious bryozoans. But in this photo there are two pieces that are "fern" shape. The longer of the two is about 1/2 inch long. They have me stumpred.

Hi, I’ve recently come back from a trip near Benson, Arizona on public land, and found this rock with a fossil. I myself am not a fossil expert or collector, but I’m curious as to what I’ve picked up, thank you. The dimensions are about 1.905 cm x 5.08cm

Picked this up in Arizona, and I unfortunately do not remember exactly where. I initially thought it might be a coprolite, but looking at it now it looks like it may be just a lump of preserved mud cracks. Any ideas on what this might be, or what would cause a rock like this to form? The rock is about 4.5x3x2 cm and shows the cracks on all sides.

I found these in Miocene lake bed limestone in central Arizona. Palm, reeds and stromatolites have been found in same layer nearby. I see no radial laminations that may indicate that these are algal growths. What are these round cap like structures? @paleoflor All the ones that I have found are round and 3 to 4 cm across. They are all shaped like spheres with the bottom 55 to 60% “missing”. The first three photos are from the top, side and bottom views. The fourth photo is of one still in the rock. The slight gap around the sphere appears to be an empty mold of the mystery object. The last photo is my drawing of what most of the fossils look like. I have an idea of what they might be. Let’s get some other opinions before I give you mine. 1 top view 2 semi side view 3 bottom view 4 in situ 5 idealized diagram

Hey there! This is my first post on The Fossil Forum. I don't have a lot of knowledge about fossils, but I sure do know how to find them. Hopefully these aren't too obvious and boring, but I'm incredibly curious anyway. I found these near Sheep Bridge north of Phoenix, Arizona. Here the Verde river has cut through deep layers of ancient lava, sandstone, mudstone, etc. I was exploring for crystals up on a steep hill along the river's canyon walls when I came across a whole lot of these things. They are very fragile and I didn't want to break apart some of the 2-3 foot wide boulders of them so as to preserve them for others to find. Anyway, my understanding is that this area was once a sea floor, so I'm assuming they are some type of coral, anemone or something similar. The fossils are composed mostly of the same sediment which encases them, so I suppose they must be trace fossils, but please correct me if I am wrong. Other not-so-filled-in ones even had crystals and other minerals lining the cavity. As well, I looked at a geological map of Arizona and the area I was exploring is composed of the following... Late to Middle Miocene Basaltic Rocks (8-16 Ma): Mostly dark, mesa-forming basalt deposited as lava flows. Pliocene to Middle Miocene Deposits (2-16 Ma): Moderately to strongly consolidated conglomerate and sandstone deposited in basins during and after late Tertiary faulting. Includes lesser amounts of mudstone, siltstone, limestone, and gypsum. There are a couple photos of some ball shaped objects which were very easy to knock apart from the surrounding stone. I have no idea what those could be. The rest of the photos are of the coral looking objects. Some of them, if still intact, were nearly 24 inches long, but I left those behind and only took smaller samples. Please note how the "head" of the corals appears to flare out and is larger than the rest of the stem. Finally, some of them appear to have a little node sticking out of the "head," but I suspect that may be due to weathering as these are very fragile fossils. Thank you all so much for your interest and help and I look forward to learning more!

Hello, I have been finding all sorts of neat rocks and marine fossils in the desert outside of Yuma, Arizona where the Colorado river had once flowed into a large ocean. There seems to be some sort of worm creature fossilized in this stone? I would appreciate an ID on the specimen, or speculation as to what it is? Thank you.

Hello, I have been finding all sorts of neat rocks and marine fossils in the desert outside of Yuma, Arizona where the Colorado river had once flowed into a large ocean. Are these fossilized coral or sponges? I would appreciate an ID on the specimens, or speculations as to what they are? Thank you.

Hello, I was trying to find the identity of some marine fossils I found, and found this great forum! I am from Montana, but have been wintering in Yuma, Arizona. I have been finding all sorts of neat rocks and marine fossils in the desert outside of Yuma where the Colorado river had once flowed into a large ocean. I have found several roundish rocks that seem to have fossilized marine life in them? I was told by a Coprolite collector that is a characteristic of Coprolite found in this area? I would appreciate an ID on the specimens, or speculations as to what they are? Below is one specimen, different angles, notice the square holes!? Thanks!

Found this not far from the other footprints. This is sandstone. I can’t really tell for sure.

I found the silicified and brecciated laminar structures in Miocene lake deposits north of Phoenix, Arizona. Could they be disturbed algal mats? I envision a drying algal mat in a lake that is disturbed by an event such as a flood, windstorm, landslide or earthquake. Compare to Kinneyia trace fossil: https://woostergeologists.scotblogs.wooster.edu/2015/10/23/woosters-fossil-maybe-of-the-week-kinneyia-ripples/ Confirmed stromatolites occur nearby in the lake sediments. Photo 1: typical wrinkled/ cracked marks in surface of laminar structures. Photo 2: typical piece of folded and brecciated laminar structures. Photo 3: detail of photo 2. Photo 4: edge of rock in photo 2. 4.5 cm field of view. Photo 5: Another piece. Photo 6: detail of photo 5. Photo 7: edge of photo 5. 3 cm field of view.

Hi everyone, I am not sure how to navigate any of this. It's my first on a forum of any kind. It may take me some time seeing how it works. Thanks for the opportunity. I live in Ft. Mohave, AZ.

Miocene lakebed deposits north of Phoenix have revealed more than palm and unknown reed like plants. I found stromatolites preserved in black, gray and white chalcedony. Although not as common as in the Precambrian, stromatolites still occur in oceans and in lakes. See article about the ones in Utah’s Great Salt Lake: https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/is-there-coral-in-the-great-salt-lake/ My favorite one is this 10 cm high detail of a much larger stromatolite. #1 This 38 cm one came home with me. #2 Here is a detail of #2. 9 x 13 cm. #3 Here is a 6 cm high relatively flat stromatolite. #4 Detail of side of #4. Scattered pieces of palm occur. 9.5 cm high. #6 This silicified palm has calcite crystals growing in it. 13.5 cm long. #7 Detail of #7. It looks like an art piece.

Hi All! I found what looks like petrified wood near Burro Creek near Wikieup Arizona. There is a lot of rhyolite in the area as well. It looks tree-ish but just looking for an ID either way.

Turned this approx 4 sq. ft. rock over today. Lots of footprints and a nice tail drag.