Search the Community

Lots of large Inoceramus bivalves from the middle unit of the Pierre Shale (kpm). Almost every rock I flip over is a bivalve been having fun hiking around

Found this rock in southern colorado. Strange, squares, seemingly fibers of some sort.

Is this a measly clam or is it a mother nature made stone? The more questions I asked, the more knowledge I'll gain

Good evening to my fellow fossil lovers! This report has been on hold for a while, hovering near the top of my paleo-to do list. But to be honest, I haven't been on the forum as much these last few months and I've just sort of kicked the can down the road, pushing it off. Well here we are in August 2022 and I'm a whole year and some change removed from this excursion, but I say better late than never. With that out of the way lets jump into this adventure! I hope you're ready for... The Roadtrip Through Time: Colorado Part I: Pierre Shale In the winter of 2021 I had the beginning of an idea... Something a bit ambitious, but within the realm of possibility. I wanted to organize a road trip which would bookend my already scheduled excursion with PaleoProspectors to hunt for dinosaurs in Montana during the last week of July. I present this idea to Quincy @Opabinia Blues, a friend I had made on my trip to Wyoming in the summer of 2020 and a native of Colorado, who would also be hunting the same week in the Hell Creek. My idea was to fly into Denver to meet with him, visit several spots throughout the state and eventually make our way north into Montana. Joining me on the trip from New Hampshire would be my best friend of over a decade, Michael @Mickeyb06. With a week of hunting the Lance under his belt from the year before, I knew his eye would be better, resulting in him finding more this time around. Several months of creating routes, researching accessible sites and forming itineraries led us all the way to mid July, when Michael and I would fly out of Boston Logan to Denver. By the time we had landed and met Quincy it was already mid afternoon. Quincy presented us with two options, head home for the evening or push on to one of the fossil sites. Ready to explore, I chose the latter. We decided to stick to our plans and head west into the mountains. The first site on our tour would be in Kremmling to hunt exposures of the late Cretaceous Pierre Shale. While I could have chosen this area or the Baculite Mesa, I decided I would prefer the mountainous scenery. Of particular note was the Kremmling Cretaceous Ammonite Locality, a protected zone where collecting was prohibited. Within this zone were dozens of calcareous sandstone concretions, many of which preserved the impressions of the giant ammonite Placenticeras and other marine invertebrates. This environment is interpreted as storm deposits of near-coastal sand bars, with the accumulation of ammonites coming as a result of their mating rituals, subsequent mass death and eventual deposition (similar to what was featured in Episode 1 of Prehistoric Planet!). After rain, water collects within these great molds, creating natural bird baths, a colloquial nickname for ammonites of this caliber. A view of the adjacent ridgeline and the mountains which surrounded us. Note the hazy sky due to wildfires elsewhere in the state. Candid shot of Michael. The winding trails. An assortment of smaller invertebrate fossils we found in the first few minutes, clusters of inoceramid bivalves and partial ammonites. Information plaque which included a beautiful illustration by Ray Troll. The first birdbath ammonite we found, with a large section of Baculite included. Another birdbath, GoPro for scale. After checking out the site for a while, we ventured outside of the protected zone onto surrounding BLM land to hunt our own non-vertebrate fossils. A beautiful piece of petrified wood. A partial cast of an inoceramid bivalve. One of my only pieces of ammonite that afternoon, a small segment of baculite. My last find of the day, a big chunk of Cretaceous sea bed, covered by the shell impressions of its long dead inhabitants (small inoceramids and a baculite). A beautiful sunset through a hazing Rocky Mountain sky. Stay tuned for more, because there is plenty to come!

Took a trip down to my childhood museam and found a little corner I missed back in the day with some beautiful ammonites and baculites

Hi everyone, it’s been a while since I have posted on here. Next summer my family is moving to the Fort Collins area and I was wondering if there were any sites or natural areas to hunt/collect in. I read on fossilspot.com that the south shore of Horsetooth Reservoir (west of Fort Collins) contains Late Cretaceous Fox Hills formation containing “Inoceramus, Ostrea, etc.”. I have already planned to get down to Florissant Fossil Quarry (despite the extremely expensive one hour access fee). My mom has friends with ranches in the central part of the state that have extensive land with mountain ATV trails. I’m still working out the formations of the area, but hopefully they are vertebrate bearing. If they are and include dinosaurs or phorusrhacids, then I would be more comfortable to brave the Mountain Lions, Fire ants and rattlesnakes for them. Near my mom’s friend’s ranch is Monarch Mountain, which is built on Ordovician rocks full of fossils. It is unfortunate that there is not many vert sites in Colorado that you can collect at. However, I will take invertebrate sites too. Of invertebrates I want Baculites or Placenticeras. Any help appreciated.

Hello everyone, I am going to be mainly in the Aurora area and possible Denver area during some part within the next month amd was wondering if there are any public sites locally and legally to find fossils. I don't mind if they are invertabrate sites as I do prefer those over vertabrate(however I don't mind vertebrate fossils either). All I have found online is the Florissant Fossil site and the normal tourist attractions where collecting isn't allowed/permitted. I don't overcollect and tend not to dig just to be on the safe side, both legally and for not damaging the landscape and/or fossil(s). Any help woyld be greatly appreciated! Thank you!

Hello! I bought this 1'' Diploducus tooth a couple weeks ago, But I've seen other people who have teeth that look the same as mine and theirs is labeled as "Diplodocidae" teeth, mine is labled as Diploducus sp. So I was wondering if it's just a Diplodicidae tooth or still a Diploducus sp.

Here is a rock/fossil from Moffat co. Colorado USA. Any ideas if it is a bone fossil? If so, what might it be from? It was found on the surface of a very rugged old road with no other similar looking rocks in sight. I did find a fossilized shell not far away (20 m).

Found these teeth while hiking at Pawnee Buttes last year and am unsure what they belong too. My top guess would be Oreodont though.

Hello all, Need help ID this insect larva from the Eocene Green River Formation of Colorado. It's 1.5cm long, about 2cm if outstretched. As far as I can tell it has a series of large, bulbous protrusions spiraling along the length of its body, and one end has a sharp taper/point, though I'm not sure if that's the head or tail end. It has a very distinctive look so I feel like it would be recognizable if it's something that's been described before. Any help appreciated, thanks.

Hey, headed into Denver tomorrow, passing Dinosaur Ridge in Morrison, then down to Colorado Springs. Can anyone point me in a direction to search for a few fossils along the way? I have heard Florissant is productive, but anywhere else between Denver and Colorado Springs? Thanks for any help,

My first fossil hunt post. Yesterday (May 29 2022), I went down to the Florissant Fossil Quarry in Florissant Colorado. Its about a 45 minute drive west of Colorado Springs. Its a very well know site partly because of the very well preserved fossils and relative abundance but also because of how easy it is. You pay a small fee and they give you the tools and you pick up shale and start splitting, that simple. You're guaranteed to find something if you try. If you are in the area I would definitely recommend stopping by, its just not really on the way to any popular stops. There is also the Florissant national monument, separate from the quarry, where you can see the massive petrified tree stumps and learn about the fossils in the formation. Attached is an image to show you, I did not take this picture since I didn't go to the monument this time. I had gone prior and really liked seeing this giant fossils. It appears as if it is frowning. The "eyes" are sawblades that got stuck when people tried chopping it down over 100 years ago. You can't use a saw to cut a petrified tree this large though. There used to be many more but they were sold to people all over the world many years ago. Walt Disney even bought one for Disneyland. It was a very nice day at 65 F (18 C). This is what the exposure looks like. You are not allowed to collect from the exposure itself, hence the rope blocking it off. You have to settle for the piles of shale shown in front, which still contain many fossils inside the paper thin shale. The most common fossil besides unidentifiable plant material are leaves. Here are the ones I kept. I believe the next three are of the genus Fagopsis, one of the more common ones. They are 5.7, 3, and 3 centimeters respectively. I measured down the stem, I'm not sure how to properly measure a leaf fossil. Do you measure the stem, the slant height, the circumference? No idea. The next one is the largest one I found, a 7.7cm Willow leaf, family Salicaceae. I am terrible at leaf identification, and all the fossils I found this trip really. I looked through The Fossils Of Florissant book by Herbert Meyer, but still am not certain on many of my finds, so if anyone can identify them I'd appreciate it. From the largest leaf to the smallest, this one is only 7mm long, it split cleanly so I have both sides of it. However some material stuck to both sides. Here's some more leaves for you. 2.3cm Koelreuteria allenii, also 2.3cm 3.7cm for the longer one. 5cm Two and a half centimeters. Three centimeters. The next two seem like they would be easy to identify but I couldn't find a similar picture in Meyer's book. The first one is 2.4cm long and the second, 1.5. The detail that is persevered is incredible. It looks just as detailed as a leaf I could find in my front yard. Here's a close up of the leaf above. The "circle" has a 10mm diameter. This one is a winged maple seed, likely Acer macginitiei and is 11mm long. A knot on some wood, only 5 mm long. Here are the insects. Only 1.5mm long. The wings are barely visible. This one looks like a fly, order Diptera. I have both sides, unfortunately the other one isn't very good. Its half a centimeter long. This one is also a fly I'm guessing. Its 4mm long. An odd one, 5mm long. An unknown larva. Its 0.4mm long. Florissant is one of the rare places where eyes can be preserved. And last but not least are the four gastropods I found. They are very tiny but very interesting. The first one is only 3mm wide. It was split open so I have the positive and negative. This one is only 2.5mm wide, possibly the best preserved out of the four though. The "large" one, 4mm long. This one is also about 4mm long. The first and fourth gastropods are a yellow color whereas the other two are a pearly white. That's everything, I hope you enjoyed it. Again, thanks if anyone could ID anything, and thanks for reading this far and looking at the photos. I truly appreciate it.

I'm going to be taking a trip to the southwest (Colorado, Utah, New Mexico and possibly Texas) pretty soon, and I was wondering if anyone could give me some ideas as to where I could go fossil hunting. I'll provide the specific areas we'll be traveling to; I also previously lived in Colorado and have already found a few good sites, but would definitely be open to any other suggestions. Colorado seems pretty promising with some good fossil quarries (Florrisant Fossil Hunting and the Morrison Museum), and I grew up with the Denver Museum of Nature and Science as well as Dinosaur Ridge. I'll mostly be in the Denver and Colorado Springs areas. Utah is where I'm having a bit of trouble; I've heard it's definitely fossil country, but I can't find a lot of tours or places where you're actually able to take fossils home from. The main one I'm thinking of right now is the U-Dig Fossil Quarry, although I don't have any other ideas as to where we'll be going in Utah (wherever the fossils take us, I suppose!) so we're likely just going to plan around where we hear the best fossil sites are. New Mexico is a state we're visiting not just to find dinos, but to see the lovely Santa Fe, which is the main area we'll be near. We don't really have any plans as to where we can go for fossils yet, but I assume there might be some good spots we can hit along the way. Texas is kind of up in the air right now. I found some amazing fossils last time in Glen Rose, and intend to return there as long as my family is also willing to make the trip. It's a bit far, but if anyone knows of any other fossil sites that would be worth visiting around the Fort Worth/upper Texas area, I would love to hear about them. I have a feeling we'll be able to go back there as long as we don't stray too far into inner Texas (i.e. anything further down from Dallas). Hopefully this is in the right place, and I would love to hear everyone's thoughts. Thanks in advance!

It has been some time since I posted anything of note. I'm still adjusting to my new surroundings here in Colorado but I did at least join a local Paleontological Society (WIPS) Western Interior Paleontological Society. My first field trip with the group was out to Baculite Mesa in Pueblo, CO. A location that is famous with a storied history, that is still giving up its ancient treasures. The weather here in Colorado can be touch and go at best, and our trip was almost delayed/cancelled by a late winter storm. This was our neighborhood in Denver the day before the trip. But temperatures rose fairly quickly (?) and the rain/snow abated enough for a window to open into the past. I brought the kids along on this trip. Here are the kids speeding along the ancient ocean bottom, which reverted to 4-6 inches of mud after the rain/snow. It returned to its roots you might say, and in the process my children grew 6 inches that day !! ... until dad had to scrape the sticky mud off of their shoes. 30 minutes later ?? .. yes, they were 6 inches taller once more. Screaming across the muddy ocean bottom. Here is our fearless leader Malcolm Bedell braving the mud and standing in front of one of the many "teepee buttes" that dots the landscape. These ancient methane seeps were built up by small communities of worms, bivalves, gastropods, crabs and the like. Food provided by the methane fixing bacteria at the seeps, and the communities of critters creating these limestone mounds. A closer look at one of these small communities. The baculites (mostly Baculites scotti) can be found eroding out of the shale and concretions that dot the landscape. This is how they typically present themselves at the site. It is rare, but occasionally you can find the Baculites with some of their original nacre still attached. But something to "fix" the nacre to the core is recommended. I think the wet mud helped to preserve this shell until I could return to the car and consolidate it .... the exercise was akin to lifting a shattered pane of glass lying on the ground to safety. Next time something to consolidate the nacre in the field and tin foil would be advised. The second location we moved to in the flats, was cut by many small and large arroyos, and could at times be treacherous for man and beast. This poor cow twisted it's legs on the way down into one of these arroyos (steep-sided gully) and had been lying there in the mud for some time, unable to move. These arroyos cut deeper into the Pierre Shale and most of the fossils here present themselves in hard concretions. I wasn't able to hang around for too long in this location. The cold and mud was too much for the kids and they retreated into the car. Next time I know what to look for and will be better prepared. I know next time will be more successful. Visually I know what I'm after and where to find it. The area is quite literally littered with fossils. I left most where I found them, eroding out of the muddy landscape. Next time I will explore the sides of the arroyo and bring a nice 3lb hand sledge. Here are ammonite bits .. found within eroding concretions. The desert has begun to bloom once again. Cheers, Brett

I found this tooth today in Colorado Springs. In the Pierre Shale formation. It looks very shark tooth like. I prepped it out a bit to expose it more. I think it might be Pseudocorax granti ? ... but I'm not sure. Could this be a shark tooth and if so what species?

A rather strange insect from the Florissant Formation of Colorado, looks like a larva or some sort of soft bodied insect. The first piece, in better condition: And the second piece: I can definitely see segments and it seems to be a close match to this Tipula hepialina (crane fly) pupa from the iDigPaleo system: Do you guys think it fits? Thanks in advance!

Hello! I'm traveling to Colorado Springs this summer. And I'm hoping to do some fossil hunting within an hours drive of Colorado Springs. I'm a geology graduate from James Madison University in Virginia and I love to collect invertebrate fossils to share with the kids I teach. Anything from ammonites to crinoids to leaves. Any advice on where to look? Thanks!

I have been a little bored lately and missing micro matrix searches. It’s been awhile since I’ve gotten to enjoy hunting for tiny shark teeth. I got some more matrix from the Rollins Member of the Mesaverde Formation. My first time through that matrix produced one of my favorite finds, a 1mm Scyliorhinus tooth. This formation doesn’t provide much in the way of complete teeth but it is a fauna that was really quite diverse. The first search was with less matrix but I found enough to want to do it again. This time I have more matrix and in varying states. Some is broken down, some is in small matrix bits and we have a small piece of untouched matrix. It’s a good chance to practice breaking matrix down and learning a broader approach to collecting. The first search of the broken down matrix and first look at the small bits has yielded few complete teeth but a much wider diversity which makes it fascinating. The first Squalicorax, Ptychodus, Lissodus, and Rhinobatos. It also produced an Orectolobiformes that doesn’t appear to be Chiloscyllium. It looks much more similar to Restesia. I am really looking forward to searching more as the breakdown goes forward. I am going to take closer pictures tomorrow but the first time finds are among the teeth in this picture.

I’m wondering if these two teeth (both are from the Morrison Formation in Moffat County, Colorado) have been identified correctly as Allosaurus and Marshosaurus. Here are the measurements of both: Allosaurus: 4cm long serration count is 10/5mm on anterior and posterior carinae base length is 21mm and base width is 13.5 mm (note from dealer: Please note that the base of this tooth is broken and the transition of enamel to root is not present. The base measurement may have been larger.) Marshosaurus: 4cm long serration count is 18/5mm on anterior and posterior carinae base length is 15 mm and base width is 8mm (note from dealer: Please note that the base of this tooth is very near the enamel to root transition a represents a fairly complete tooth.) The serrations on the anterior keel of the tooth extend two-thirds of the distance from tip to base. Images seem to be weirdly mismatched, but I think it’s pretty easy to tell which pictures match with which.

Hi everyone! I have my eye on a nice size sauropod tooth from the Morrison but before going for it was hoping to get some insight from an outside source as I have zero experience with the Morrison. The seller claims the tooth is 2 inches and was found in Moffat County, Colorado. He can't tell if it's Diplodocus or Apatosaurus either so any potential insight or tips on that would be greatly appreciated as well for this and future reference.

Hello! This is a canine tooth (that has been split in half) that I collected from the White River Formation (I believe Poleslide Member of the Brule) from Weld County, CO. I think it is a carnivore’s canine rather than simply an Oreodont canine just due to its size, but I could be wrong there I suppose. My best guess is Daphoeneus or similar due to its shape, it does not look like Hyaenodon to me, but again, could be totally off there. Pictured is the tooth’s lateral surface, interior (because it was split when I found it) and the “cutting surface.” Thanks!

I have finally come to the end of my fun with the “Mesaverde Formation” matrix. There are a few unidentified shark fossils left. I know they may remain little mysteries and that’s ok but still worth a try. It was labeled Mesaverde by the seller but I strongly suspect it could actually be Mancos Shale. It did come from Delta County Colorado. As far as age goes, the best guess I have is Cenomanian-Turonian but it could be younger. There were Cretomanta teeth present but I honestly don’t know if they are found beyond the Turonian age. Thats all the info I can provide about the matrix itself. On to the teeth. 1. Scyliorhinid ? I believe this is the smallest tooth I found, under 1mm. I think it’s a Catshark but I figured I would get some other opinions. So small it was hard to photograph and move around to get better angles.

Hi All, This past summer, my daughter and I went to a couple of sites in the Green River Formation to look for leaf and insect fossils. Here's a video we made about our trip and findings. We also visited the Field House of Natural History in Vernal and the curator took us on a tour of the collection. cheers, Lloyd

Hi all, new member here! I was exploring "Dinosaur Ridge" in Colorado near Red Rocks and found this interesting looking piece - any ideas as to what the cut-out bit might be? It's from the Morrison Fossil Area, which I believe produces Cretaceous period fossils. The part in question is about an inch long. Let me know if anybody needs more info/pics to help ID, thanks to all!