A wide diversity of fossils may be found in Arkansas. The map shows where some of them have been found. Below the map is a list of known Arkansas fossils. It is very much an incomplete list, but it will grow with time. A link is supplied for every fossil which has been discussed in more detail thus far on Paleoaerie. Just click on the name and you will be taken to its description. Most of the descriptions were done as part of a Mystery Monday fossil identification series. You will quickly see that this list is heavily weighted towards vertebrates. That will change as I have more time to delve more deeply into the invertebrates. Partly this is due to the fact that many of our most common fossils are invertebrates which cannot be very closely identified, such as crinoid stems, which can only be identified any further than “crinoid” except possibly by crinoid experts. In those cases, going further into them will not serve the vast majority of people, and as I am not a crinoid expert, I couldn’t do it anyway. The other reason for this bias is that I am more familiar with vertebrate fossils. If anyone who knows a good bit about Arkansas invertebrates and would like to write an article for Paleoaerie, please let me know. Input from other knowledgeable people is always welcomed.
The following list does not precisely follow phylogenetic relationships. It is very simplified, designed to make it easier for nonspecialists to quickly find organisms they are interested in. Perhaps in the future, a phylogenetic map showing more detailed relationships will be added, but that will not be in the foreseeable near future.
If you know of fossils that are not on the list, please contact me and it can be added to the list.
Arkansas Geologicl Survey regional map, annotated with reported fossils.
Stromatolites – microbial algae mats
Plants – Calamites, Lepidodendron
Porifera
Demospongia – Haplistion sphaericum, Virgaspongia ichnata, Cliona
Hexactinellida (glass sponges) – Stioderma hadra
Cnidaria – tabulate and rugose (horn) coral
Arthropoda
Arachnomorpha – trilobites, other chelicerates
Crustacea – ostracods, barnacles (Brachylepas, Virgiscalpellum), copepods, decapods (crayfish, Imocaris tuberculata)
Insecta – Phylloxerids (aphids), Blattodea (cockroaches)
Formicinae (ants) – Protrechina carpenteri
Annelida – Serpula (polychaete)
Mollusca
Cephalopoda – ammonites, goniatites, nautiloids (Orthoceras, Rayonnoceras)
Gastropoda (snails)
Bivalvia (clams) – Exogyra ponderosa, Exogyra costata, Gryphaea, Ostrea franklini, Ostrea fulcata, Nuculana
Lophophorates
Bryozoa – Archimedes
Brachiopoda – Strophomenids, Spirifers, Productids, Lingula
Echinodermata – Crinozoa (crinoids), Echinozoa (sea urchins), Blastozoa (sea urchin-like, such as Pentrimites), Asterozoa (sea stars)
Hemichordata – Graptolites
Conodont – Gnathodus, Cavusgnathus
Fish
Actinopterygii – Lepisosteus, Arius, Trichiurus, Sphyraena, Diaphyodus, Enchodus, Paralbula, Pycnodus, Hadrodus, Stephanodus, Protosphyraena
Chondrichthyes – Aetobatis (eagle ray), Myliobatis (sting ray), Ozarcus, Ginglymostom, Dasyatis, Abdounia, Galeocerdo, Galeorhinus, Carcharias, Prionodon, Pristis, Hemipristis, Dicrenodus, Cladodus
Reptilia
Lepidosauria – Mosasaurus, Platecarpus, Elasmosaurus
Squamata – Pterosphenus (Choctaw giant sea snake), Coluber, Pituophis, Crotalus
Testudinata – Prionochelys, Trionychid, Chedighaii, Toxochelys
Crocodylia – Goniopholid, Sebecid
Dinosauria – Acrocanthosaurus, “Arkansaurus”, Titanosaur (Sauroposeidon?), Deinonychus, nodosaurid ankylosaur (Borealopelta?), Richardoestia
Mammalia
Xenarthra – Megalonyx (giant ground sloth), Dasypus (armadillo)
Afrotheria – Mammut (mastodon), Mammuthus (Mammoth)
Boreoeutheria
Pantolestes
Carnivora
Feliformia – Smilodon fatalis (“saber-toothed tiger“), Lynx rufus, Panthera onca , Puma, Miracinonyx studeri
Caniformia – Canis (C. lupus, the gray wolf and C. dirus, the dire wolf), Canis armbrusteri, Canis latrans, Vulpes (fox), Procyon lotor (raccoon), Urocyon cinereoargenteus, Mephitis mephitis, Mustela frenata, Mustela erminea, Mustela vision, Pekania diluviana, Brachyprotoma obtusata, Arctodus (giant short-faced bear), Ursus americanus, Spirogale putorius (eastern spotted skunk)
Glires – Lepus americanus(rabbit), Lepus alleni, Sylvigilus floridanus, Castor canadensis (beaver), Peromyscus, Microtus paroperarius, Microtus llanensis, Tamiasciurus, Ondatra, Geomys burasrius, Reithrodontomys, Neotoma ozarkensis, Ondatra annectens, Pitymys cumberlandensis, Spermophilus, Marmota monax, Tamiasciurus hudsonicus, Erethizon dorsatum, Scalopus
Chiroptera (bats)– Eptesicus fuscus, Myotis leibi
Cetioartiodactyla – Basilosaurus (primitive whale), Cervus, Mylohyus, Odocoileus virginianus, Diplobunops, Bootherium bombifrons
Perissodactyla – Equus scotti
Soricomorpha – Blarina brecicauda, Scalopus aquaticus (eastern mole), Sorex cinereus, Sorex funeus, Sorex minutus, Sorex monticolus
paleoaerie 
Just south of Greenland is an old section of highway 71 south. The oldest part of the road goes across an old iron bridge and runs by a church. The river bed near the bridge contains a deposit of sharks teeth so I’ve been told. For what it’s worth under the Walmart parking lot on highway 62 west in Fayetteville are some large ammonite fossils. I’ve actually seen those. Good hunting and please let me know of good spots to look… preferably ones with owners that don’t shoot on sight. 🙂
Thanks for the tips! Fayetteville is actually famous for having some of the largest straight-shelled ammonoid fossils ever found in the world. It is a great place to hunt for fossils. The only hard part of fossil hunting around there is avoiding Federal National Forest land and unwelcome private owners:). But some amazing fossils have been found in some interesting places. An eight foot ammmonoid shell was found in a drainage ditch beside a highway near Fayetteville, which is public property and open for anyone to collect. Actual reports are a bit confused as to exactly where as they say Interstate 540 in Fayetteville, although I-540is in Fort Smith, not Fayetteville, but at any rate, any ditch that has shale in it around northwest Arkansas has the potential for some interesting fossils. A lot of people collect along I-65 around Leslie. That is probably the most popular collecting area. Any of the roadcuts along there have produced lots of fossils, including a world-famous shark fossil by the name of Ozarcus.
If you get in touch with the people of the Central Arkansas Gem, Mineral, and Geology Society (CAGMAGS), they sponsor a lot of collecting trips. The University of Arkansas at Fayetteville Geology Club is also pretty active usually and may sponsor trips. I don’t often get to that part of the state as much as I would like, but I will be getting up there a few times in the next couple of months, so I may hear more this summer. If you hear more, please let us know.
I found a stand fossle could you help me identify it?
I would be happy to try. Send me some pictures and I will see if I can identify it. If I can’t, I know people who should.
I found a rock with what looks like a bunch of crustacean fossils took it home and gave it to my son he has been trying to ID some of the fossils but haven’t had any luck I was hoping you might be able to point us in the right direction
I’d be happy to help if I can. Email me (paleoaerie@gmail.com) some photos and I will take a look. Where did you find it?
Greetings I’ve worked the Fayetteville Shale for 21 years a side step from previous work mining rare minerals in Arkansas . I’ve studied what little there is concerning the Fayetteville Shale ended up recovering a 7’ nautiloid which was reported in our local news years ago . I bough a private property lease that took 17 years to locate its very rich in fossils as we’ve donated the majority to the U of A ….. big mistake they sold over half of them quietly . Recently this year our first 43’ complete fish followed by several amazing jaws full of teeth and large shoulder blade all are matched with the first air breathing animals none have ever been discovered in Arkansas or in the Shale layer . Recently searching for the right people to examine the finds without attempted theft of my work which already was attempted . I had to actually turn loose my attorney on these people …why some people attempt to confiscate my work because they are quite envious of my work . My goal is not in any value of selling my discovries but to share information of extreamly rare fossils . Now as to my attorneys advice the fossils have been located in a safe place stored in a vault controlled by my attorneys all because of greedy people whom despise my years of work . Here is the link to my YouTube video so you to can see how incredibly rare these finds are . I recently spoke with my long time now retired friend Mike Howard Ex State Gelogist last week as what to do and how to share information without worrying about certain people abusing their position in a attemp to take my hard earned work .
Please please contact me but only if your truly wanting to share needed recorded new one of a kind fossils . I don’t have any time to fight more thugs abusing their position to gain personal noterity and leaving my work out completely . 21 years of hard hard work and thousands of dollars of my own money working on the Shale layer ….
Oh, how I would love to see your work and finds but I’m afraid your expertise would be wasted on my uneducated mind. I am
an extreme newbie at searching and learning about fossils of any kind. Oh, but I love the hunt!!!! Thank you in advance for all your time, energy, and money spent in preserving your rare finds for future generations. I’m trying my best to get my five year old granddaughter interested at an early age. Hopefully one day soon, you will have a museum, that you can place your finds on display, for those of us, that only dream of finding a common fossil let alone a rare one, to enjoy. Do you personally know of any place open to the public that I could take my granddaughter to with easy to moderate excess. I am not as young as I once was and getting around is doable but no extreme hiking or climbing. I would be willing to pay a small fee of course for the privilege to hunt. I am limited on a fixed income. Thank you for any info you can share with me. I am located in central Arkansas but willing to travel within the state.
I am so sorry for taking so long to respond to you. thank you so much for kind words. I would love to get a museum in Arkansas to showcase our wonderfully diverse natural history so that more people can appreciate what we have here. I am truly glad to hear from people who share such a vision. There are several good places you can hunt for free as long as you are on state land, which includes all the roadcuts. If you take US Highway 65 north from Conway up to Marshall and the Buffalo River, there are several roadcuts, particularly near Leslie that you can collect fossils for free. Just mind the traffic and no collecting in the Buffalo National Park. There is a roadcut just north of Leslie that produced a fossil of a shark named Ozarcus that made international news. There are numerous fossils that are much more common, which you should be able to find with a little time and effort. You can also go to several creeks around Arkadelphia which will turn up thousands of large clams and the occasional mosasaur, as well as several streams around Malvern which have plenty of shark and Enchodus teeth (you can distinguish the Enchodus fangs easily because they are conical and lack a cutting surface). All of these are spots that are completely free and relatively easy to reach. good hunting!
I can’t believe I haven’t replied to this before. I am terribly sorry. It looks like you have some amazing material there that I would love to see. I completely understand your reticence and I am sorry to hear about the U of A selling your fossils. That should not have been done. Rest assured, anything you show me that you permit me to show others will always have you credited with the discovery and owner of the fossils. My only interest is in getting the word out about the types of fossils found here. What we have here is little known or appreciated even by people within the state, which is a shame because we do have a wide diversity of fossils. I would take it as an honor to see those amazing fossils you have found.
I found Lepidodendron, Calimites, crynoids, and some bivalves on the shore of Greesferry Lake (Fairfield Bay, AR). A lot of bioturbation. Maybe a mastodon tarsal? It was pretty awesome; I grew up here and had no clue I was surrounded by so many fossils!
That’s fantastic! That is a good area to look for fossils and is a lovely place to spend time hiking about. It is certainly possible you found a mastodon fossil. We know they lived in that area. The Arkansas Geological Survey has some mastodon material you could compare your fossil with along with several people knowledgeable about them to help you if you want to get it checked out.
I have i think is a pecten fossil found in northeast arkansas on crawleys ridge north of jonesboro would u please look at it and tell me if it is what i think it is
I would be happy to. Can you send me pics at paleoaerie@gmail.com?