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Hello, I picked up this small trilobite with no provenance or label. However based on the other material it was with I suspect it is Pennsylvanian-aged possibly from Kansas. Can anyone verify the bug and potentially the provenance as well? The long pygidium makes me think of Ameura, and I believe the lack of a median preoccipital lobe rules out Ditomopyge. However compared to other examples I see the glabella seems narrow and the cheeks very wide, so perhaps I am completely off. Any thoughts would be appreciated.

I've been going through some of my micro matrix pictures from the Waurika Permian site I visited in May and this little tooth has me thinking it might be Dimetrodon....the shape is possibly correct and there is just a TINY bit of evidence of carina on one edge. Perhaps a juvenile? It's tiny tiny....3 mm . You can just barely see the carina on the left side

Hello all, I have been sorting through some more Waurika Permian micro-matrix recently, and I was excited to find not just one, but two claws in one day when I hadn't found a single one before this! One is larger than the other and more curved and fearsome looking (well, as far as microfossils go). The bigger one is just over 4mm and the smaller one is a bit over 2mm. I also included a piece which looks maybe like a weird helodus tooth, maybe a fish mouth plate, or maybe a tiny prehistoric iron. Its size is just under 4mm. I'll summon the experts who helped me out last time, @ThePhysicist and @jdp, would you mind taking a look at these? Claw # 1: 4mm Claw #2: 2mm Unknown fishy bit: 4mm That's all, thanks for looking!

Hello dear fellow forum members. I acquired an interesting fossil supposed to be an Intercentrum attributed to Dimetrodon. Sellers Info:Lower Permian, Wellington Fm. , Waurika, Oklahoma A forum member informed me that at least in adult Pelycosaurs there should not be a separate Intercentrum. So I am open to your Suggestions- Is it someone elses Intercentrum, is it something completely different? I hope that the structure of the fossil will lead to some ID. Fotos from the seller, because I cannot take better ones at the moment. Sorry for the absence of an exact scale, but you get a general impression of the size. Best Regards, J

Well, 2 days ago I was freezing my butt off in Chicago and today its almost 90 degrees here in Oklahoma! But warm dry weather is perfect hunting time, so I headed out to a ranch I started searching last year. After many hours of walking and eyeballing every bit of rock exposure, something finally caught my eye. I immediately recognized the bone structure, marked the spot and kept searching. More and more bits started to show up and I immediately recognized the "figure 8" shaped that is distinctive of the sail spines of Dimetrodon! This is the animal I have been hoping to find since I began my research into Oklahoma fossil locations. I was super excited. These were found on surface as "float", so I marked every spot with engineer tape. When I couldnt find any more, I stood back and looked at a perfect triangle pointing to the highest spot where I found material, and it was also several bits together. So now I have an arrow pointing to my dig site. My only hope is that I am just finding the tips (since almost all of it was sail spine bits) and the rest of it is still in the ground waiting. Fingers crossed. Even if this is the only parts left, I'm still super excited. Most were sail spine bits and some were BIG, huge compared to what I saw on my day of digging in the Craddock bone bed in Texas. Also a few other bits that might be pieces of rib or limbs. Also, 2 bits of Orthocanthus shark headspine (actually the first items I saw) and 2 coprolites including 1 that has visible bone bits in it! @thelivingdead531 I know its been 3 years, but I'm a heck of a lot closer to finding that Ddon tooth I promised you! My field collection collection Dimetrodon sail spine bit That distinctive shape for sail spine! and another one Everything brought home Not a great pic, but the light spots are bits of bone in this coprolite. Othocanthus spine pieces. Ortho head spine showing denticles 2nd ortho head spine with denticles

A new discovery in Antarctica, which shows some extraordinary capacity of polar trees http://www.independent.co.uk/news/science/antarctica-fossil-forests-280-million-year-old-trees-erik-gulbranson-john-isbell-university-of-a8158441.html

There really aren't any great ID guides online for this site. There's one but i read it was unreliable. Looking for some pointers on these. Sorry, but this is going to be fairly long. 1. Lungfish scale 2. Fish spines? 3. Shark denticles? 4. Amphibian teeth? 4a. 4b. 4c. 4d. 4e. 4f. 4g. 4h. 4i. 4j. 4k. 4L. 4m. 4n.

The Actinopterygian fish (also called ray-fined fish) are the third major group of jawed fish (alongside the Sarcopterygians and Chondrichthyans) that emerged during the Early-Late Silurian 439-425 Million Years ago. The Ray-finned fish were at first not as abundant as the Sarcopterygians, but gradually increased in diversity during the Carboniferous and Permian periods. The Actinopterygians at this time even managed to colonize freshwater habitats. But the group did lose some diversity during Permian-Triassic Extinction Event 252 Million Years ago, though not as much as the Sarcopterygian fish. But thankfully a decent amount of Actinopterygii survived and all living Actinopterygian fish (today one of the most diverse groups of fish currently on Earth) can trace their origins to these few hardy survivors. Here's a list of all currently known Actinopterygian fish genera and families that survived the Permian-Triassic Extinction Event. If I forget any examples, please let me know and I'll add the examples to the list promptly. Actinopterygii Semionotiformes Acentrophorus (Semionotiform) (Late Permian-Early Triassic, 268-242 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=35134 https://www.researchgate.net/publication/230110387_The_Permian_Fishes_of_the_Genus_Acentrophorus https://www.nature.com/articles/042366a0 Palaeonisciformes Pygopterus (Palaeonisciform) (Late Permian-Late Triassic, 259-201 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=149731 https://www.researchgate.net/publication/263086548_A_first_record_of_late_Middle_Permian_actinopterygian_fish_from_Anatolia_Turkey https://cpb-eu-w2.wpmucdn.com/blogs.bristol.ac.uk/dist/1/555/files/2021/02/2019Jurong.pdf Atherstonia (Palaeonisciform) (Late Permian-Early Triassic, 259-251 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=263365 https://www.researchgate.net/publication/268810424_Permian-Triassic_Osteichthyes_bony_fishes_Diversity_dynamics_and_body_size_evolution Acrolepis (Palaeonisciform) (Early Carboniferous-Late Triassic, 360-201 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=34964 https://publikace.nm.cz/file/2728acfd17332bdb0a1a873988cf3595/18261/sbornik_B_3_4_www_stamberg_1_opr3-FINAL.pdf https://www.researchgate.net/publication/268810424_Permian-Triassic_Osteichthyes_bony_fishes_Diversity_dynamics_and_body_size_evolution Acipenseriformes Errolichthys (Acipenseriformes) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=241059 https://www.researchgate.net/publication/269406596_Permian-Triassic_Osteichthyes_bony_fishes_diversity_dynamics_and_body_size_evolution_Supplementary_Tables_S1-S3 https://www.frontiersin.org/articles/10.3389/feart.2020.618853/full Bobasatraniiformes Bobasatrania (Bobasatraniiform) (Late Permian-Early Triassic, 252.3-237.5 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=35078 https://www.researchgate.net/publication/258034291_Triassic_actinopterygian_fishes_The_recovery_after_the_end-Permian_crisis https://www.researchgate.net/publication/346609564_A_Hiatus_Obscures_the_Early_Evolution_of_Modern_Lineages_of_Bony_Fishes Saurichthyiformes Saurichthys (Saurichthyiform) (Late Permian-Late Jurassic, 252.3-164.7 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=65068 https://www.researchgate.net/publication/226590807_Vyazniki_biotic_assemblage_of_the_terminal_Permian https://www.readcube.com/articles/10.3389/feart.2020.618853 Hope you all find this list helpful!!!

My latests hunts to my Permian sites have been slim. Still trying to narrow down the producing layer(s), but my test excavations have been dry so far. If you remember in my last thread, one of my spots was almost buried by overburden from a dozer work above. I had a strong hunch that there would be fossils in those debris pile and I just needed some rain to start washing it down. I was right! We have been getting quite a bit of rain lately and its helping uncover more. Last week I found a couple pieces of an Orthocanthus texensis (Permian age shark) head spine. I have found many pieces like this at this site, but these 2 parts went together making about a 3 inch long section. My biggest piece yet! Today, 2 more pieces were found. This section had lovely denticles! While cleaning and talking about them with my son, I got out the last section to explain the how the complete spine would look with the smooth lower, and barbed upper pieces.... AND THEY FIT TOGETHER! What made is more amazing was that the base section was found very high on the pile, and the barbed section was at the bottom. The break on the tip is recent, and I have hope I might still find the last 1.25 inches to make this 100% complete. I might just try digging and sifting for it. Its a narrow water-dug path these came from. The base section was wedged sideways up high, maybe the tip was flushed all the way down along with the most recent find.

The Sarcopterygian fish (also called lobed-fined fish) are an ancient group of fish that emerged in the Late Silurian 425 Million Years ago and gave rise to the direct ancestors of the first land vertebrates, the amphibians during the Late Devonian. Today represented by the still living Coelacanths and Lungfish, These fish were incredibly common and diverse during the late Paleozoic. But the Permian-Triassic Extinction Event 252 Million Years ago nearly decimated the group. But thankfully some of the Sacopterygii survived and all living Sarcopterygians and trace their origins to these few hardy survivors. Here's a list of all currently known Sacropterygian fish genera and families that survived the Permian-Triassic Extinction Event. If I forget any examples, please let me know and I'll add the examples to the list promptly. Sarcopterygii Dipnoi (Lungfish) Gnathorhiza (Dipnoid) (Carboniferous-Early Triassic, 318.1-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=90709 https://www.researchgate.net/publication/278743788_Environmental_significance_of_lungfish_burrows_Gnathorhiza_within_Lower_Permian_Wolfcampian_paleosols_of_the_US_midcontinent https://www.researchgate.net/publication/291808594_The_westernmost_occurrence_of_Gnathorhiza_in_the_Triassic_with_a_discussion_of_the_stratigraphic_and_palaeogeographic_distribution_of_the_genus Ceratodontiformes https://www.researchgate.net/publication/284186167_The_first_find_of_Permian_ceratodontids_Dipnoi_Osteichthyes_in_Russia Coelacanthiformes (Coelacanth fish) Coelacanthus (Coelacanthid) (Carboniferous-Early Triassic, 314.6-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=34911 https://www.researchgate.net/publication/226724498_Erratum_to_A_coelacanthid-rich_site_at_Hasbergen_NW_Germany_taphonomy_and_palaeoenvironment_of_a_first_systematic_excavation_in_the_Kupferschiefer_Upper_Permian_Lopingian https://www.researchgate.net/publication/265184906_Coelacanths_from_the_Middle_Triassic_Luoping_Biota_Yunnan_South_China_with_the_earliest_evidence_of_ovoviviparity I hope you all find this list helpful!!!

The Permian-Triassic Extinction Event of 252 Million Years ago was one of Earth’s largest mass extinction events, wiping out around 75% of all terrestrial genera and 95% of all oceanic genera. Cephalopods (represented at the time mostly by ammonites and the still extant Nautilidae) were especially hit hard, with around 97% of all ammonite genera becoming extinct by the start of the Triassic. But those genera that survived the event formed the basis for a major radiation in cephalopod diversity. Ammonites (particularly those of the order Ceratitida) experienced an era of rapid diversification during the Triassic. Cephalopods continued to diversify in the later stages of the Mesozoic and Cenozoic eras. Here’s a list of all currently known cephalopod genera and families that survived the Permian-Triassic Extinction Event. If I forgot any examples, please let me know and I’ll add the examples to the list promptly. Ammonoidea Prolecanitida Episageceras (Prolecanitid) (Late Permian-Early Triassic, 254.0-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13964 https://onlinelibrary.wiley.com/doi/full/10.1111/j.1475-4983.2007.00653.x Ceratitida Xenodiscus (Ceratite) (Late Permian-Early Triassic, 268.0-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=14458 https://onlinelibrary.wiley.com/doi/full/10.1111/j.1475-4983.2007.00653.x https://www.pnas.org/doi/pdf/10.1073/pnas.0907992106 Otoceras (Ceratite) (Late Permian-Early Triassic, 252.3-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=14276 https://onlinelibrary.wiley.com/doi/full/10.1111/j.1475-4983.2007.00653.x https://eprints.whiterose.ac.uk/476/1/wignallpb2.pdf Ophiceras (Ceratite) (Late Permian-Early Triassic, 254.0-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=14272 https://kuscholarworks.ku.edu/handle/1808/3896 https://www.zora.uzh.ch/id/eprint/136979/1/1-s2.0-S1871174X17300434-main-1.pdf Tompophiceras (Ceratite) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=14429 https://www.app.pan.pl/archive/published/app58/app20110054.pdf Anderssoniceratidae http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=86838 Prionolobus (Ceratite) (Late Permian-Early Triassic, 252.3-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=82362 https://www.researchgate.net/publication/277925393_First_occurrence_of_temnospondyls_from_the_Permian_and_Triassic_of_Turkey_Paleoenvironmental_and_paleobiogeographic_implications https://www.zora.uzh.ch/id/eprint/136979/1/1-s2.0-S1871174X17300434-main-1.pdf Paratirolites (Ceratite) (Late Permian-Early Triassic, 254.0-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=14312 https://www.researchgate.net/publication/272149073_Importance_of_Carbon_Isotopic_Data_of_the_Permian-Triassic_Boundary_Layers_in_the_Verkhoyansk_Region_for_the_Global_Correlation_of_the_Basal_Triassic_Layer https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1475-4983.2007.00653.x Hypophiceras (Ceratite) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=82367 https://www.researchgate.net/publication/272149073_Importance_of_Carbon_Isotopic_Data_of_the_Permian-Triassic_Boundary_Layers_in_the_Verkhoyansk_Region_for_the_Global_Correlation_of_the_Basal_Triassic_Layer https://www.researchgate.net/publication/361222295_Biotic_Response_to_Rapid_Environmental_Changes_During_the_Permian-Triassic_Mass_Extinction Metophiceras (Ceratite) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=93264 https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1475-4983.2007.00653.x https://www.sciencedirect.com/science/article/abs/pii/S0921818118301322 Orthocerida https://sjpp.springeropen.com/articles/10.1007/s13358-019-00188-2 Belemnoidea Xiphoteuthididae http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=265569 https://onlinelibrary.wiley.com/doi/full/10.1111/pala.12070 Nautilida Liroceratidae Paranautilus (Liroceratid) (Late Permian-Early Triassic, 259-205 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13256 https://www.cnidaria.nat.uni-erlangen.de/tersane/tersane-papers/Korn&Gliwa_2019_The morphospace of Late Permian coiled nautiloids.pdf https://www.researchgate.net/publication/327721272_Aly_MF_2001_Middle_Triassic_Cephalopods_from_the_Musandam_Peninsula_Northern_Oman_Mountains_United_Arab_Emirates_Geo_Soc_Egypt_45_1B_463-479 Tainoceratidae Aulametacoceras (Tainoceratid) (Middle Permian-Early Triassic, 272-242 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13151 https://pubs.usgs.gov/pp/1207/report.pdf Germanonautilus (Tainoceratid) (Late Permian-Late Triassic, 254-201 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13201 https://core.ac.uk/download/pdf/39311692.pdf https://www.researchgate.net/publication/327721272_Aly_MF_2001_Middle_Triassic_Cephalopods_from_the_Musandam_Peninsula_Northern_Oman_Mountains_United_Arab_Emirates_Geo_Soc_Egypt_45_1B_463-479 Holconautilus (Tainoceratid) (Late Permian-Late Triassic, 265-232 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13216 https://www.cnidaria.nat.uni-erlangen.de/tersane/tersane-papers/Korn&Gliwa_2019_The morphospace of Late Permian coiled nautiloids.pdf https://sjpp.springeropen.com/articles/10.1186/s13358-022-00263-1 Pleuronautilus (Tainoceratid) (Late Carboniferous-Late Triassic, 298-205 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13270 https://core.ac.uk/download/pdf/39311692.pdf https://www.researchgate.net/publication/336065301_A_Changhsingian_late_Permian_nautiloid_assemblage_from_Gujiao_South_China Tainionautilus (Tainoceratid) (Late Permian-Early Triassic, 254.0-247.2 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13314 https://www.researchgate.net/publication/336065301_A_Changhsingian_late_Permian_nautiloid_assemblage_from_Gujiao_South_China https://www.pim.uzh.ch/apps/cms/_downloads/bruehwiler_2012_ammonoids_salt_range.pdf Grypoceratidae https://pubs.usgs.gov/pp/1207/report.pdf Syringonautilidae Syringonautilus (Syringonautilid) (Late Permian-Late Triassic, 254-232 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=13311 https://core.ac.uk/download/pdf/39311692.pdf https://www.researchgate.net/publication/292364105_Triassic_ammonoid_succession_in_South_Primorye_1_Lower_Olenekian_Hedenstroemia_bosphorensis_and_Anasibirites_nevolini_Zones I hope you all find this helpful?

The Permian-Triassic Extinction event of 252 Million Years (caused by massive volcanic eruptions in what is now Siberia) was one of the biggest mass extinctions in Earth's history (killing 75% of all land genera and 95% of all marine genera). The event marked the end of the Paleozoic and the beginning of the Mesozoic. Famous survivors of the extinction event include the Dicynodont Lystrosaurus, the Therocephalians Moschorhinus, Tetracynodon, Promoschorhynchus, the Archosaur Proterosuchus, and the Cynodont Thrinaxodon. One group of terrestrial survivors of the extinction event sometimes overlooked are the Amphibians, the original tetrapods. One resilient group not only survived the extinction event but experienced a rapid period of diversification during the Triassic. These were the truly iconic and mostly salamander like Temnospondyls (Temnospondyli). This group lasted from the Carboniferous until the Early Cretaceous period (330-120 Million Years ago). It’s also likely that they are the direct ancestors of today’s Lissamphibia (the most common group of Amphibians alive today). Here’s a list of all currently known amphibian genera and families that survived the Permian-Triassic Extinction Event. If I forget any examples, please let me know and I'll add the examples to the list promptly. Temnospondyli Rhinesuchidae Broomistega (Rhinesuchid) (Late Permian-Early Triassic. 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=266422 https://core.ac.uk/download/pdf/39674584.pdf Micropholidae Micropholis (Micropholid) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=37033 https://www.sbpbrasil.org/revista/edicoes/10_3/pineiro.pdf https://bioone.org/journals/journal-of-vertebrate-paleontology/volume-41/issue-1/02724634.2021.1904251/First-Record-of-the-Amphibamiform-Micropholis-stowi-from-the-Lower/10.1080/02724634.2021.1904251.short Capitosauria Lydekkerina (Capitosaurid) (Late Permian-Early Triassic, 252.3-251.3 Million Years ago) http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=267018 http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=255237 https://www.researchgate.net/publication/228494637_The_South_African_stereospondyl_Lydekkerina_huxleyi_Tetrapoda_Temnospondyli_from_the_Lower_Triassic_of_Australia https://www.researchgate.net/publication/317225232_The_Rhinesuchidae_and_early_history_of_the_Stereospondyli_Amphibia_Temnospondyli_at_the_end_of_the_Palaeozoic https://www.researchgate.net/publication/240535618_Cranial_anatomy_of_the_Early_Triassic_stereospondyl_Lydekkerina_huxleyi_Tetrapoda_Temnospondyli_and_the_taxonomy_of_South_African_lydekkerinids Rhytidosteidae http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=37110 https://www.sbpbrasil.org/revista/edicoes/10_3/pineiro.pdf Tupilakosauridae https://www.researchgate.net/publication/232672896_Slaugenhopia_texensis_Amphibia_Temnospondyli_from_the_Permian_of_Texas_is_a_primitive_tupilakosaurid I hope you all found this helpful?

I want your opinions on this piece. I picked this up today, after knocking it a few times to make sure that it wasn't "fresh". The surface texture it really rough and funky. Very much like sandstone and not what I'm used to with fossils here, but the shape... come on, how can this NOT be what it looks like? Found at my 280MY Permian site. Whats your thoughts? Is it coprolite, a very grossly shaped natural rock, or should I go wash my hands some more?

The Chondricthyans (including the sharks and rays) have been around and keeping the ocean's ecosystems healthy for about 420 Million Years. Today, in celebration of this, I've decided to do a little fun post and list the eight times in Earth's history truly massive chondricthyans have emerged. Hope you all enjoy!!! The First is the Devonian, where there is at least one confirmed fossil (CMNH 5238) of a large currently unnamed Ctenacanthiform shark that reached lengths of 4.2-5 meters (13-16 feet) in length. https://www.mdpi.com/1424-2818/15/3/318 The Second is the Mississippian stage of the Carboniferous (358.9-323.2 Million Years ago), a golden age for chondricthyans. The Early Carboniferous saw the emergence of Giant Ctenacanthiform sharks like Saivodus striatus, which grew up to 10-11 meters (32-36 feet) in length. https://www.uky.edu/KGS/fossils/fossil-of-the-month_2022-07_Saivodus.php https://www.uky.edu/KGS/fossils/fossil-of-the-month_2022-07_how-big.php https://www.nps.gov/articles/000/fossils-of-the-2023-national-fossil-day-artwork.htm The Third is the Pennsylvanian stage of the Carboniferous (323.2-298.9 Million Years ago). Like the Mississippian, the Pennsylvanian was also a golden stage for Chondricthyans where large Ctenacanthiforms continued to thrive and large Eugeneodontida edestoids like Edestus (which could grow up to 6.7 meters (22 feet) in length) emerged. Large Ctenacanthiforms from this time include the unnamed Graham Formation Gilkmanius sp., which grew up to 7 meters (22 feet) in length. https://bioone.org/journals/journal-of-vertebrate-paleontology/volume-37/issue-3/02724634.2017.1325369/A-Pennsylvanian-Supershark-from-Texas/10.1080/02724634.2017.1325369.short The Fourth is the Permian (298-252 Million years ago). There were some large sharks, like the Ctenacanthiform Kaibabvenator (which grew up to 4.8-5.48 meters (16-18 feet) in length). But Eugeneodontida by this point contained the largest Chondricthyans alive at this time including Helicoprion (which grew up to 7.6 meters (25 feet) in length) and Parahelicoprion (which could grow up to 12 meters (36 feet) in length). https://www.academia.edu/29941296/Chondrichthyan_and_actinopterygian_remains_from_theLower_Permian_Copacabana_Formation_of_Bolivia https://doi.org/10.1002%2Far.24046 The Fifth is the Early Cretaceous (145-100 Million Years ago). Though the time's aquatic ecosystems was dominated by large marine reptiles, large sharks managed to emerge and fill ecological niches from time to time. This includes the Early Cretaceous Shark Leptostyrax, which grew up to 6.3 meters (20 feet) in length. https://www.researchgate.net/publication/277782424_A_Gigantic_Shark_from_the_Lower_Cretaceous_Duck_Creek_Formation_of_Texas The Sixth is the Late Cretaceous (100-66 Million years ago). Aquatic ecosystems still were dominated by marine reptiles, but large sharks were indeed present. This includes Cretodus crassidens (which grew up to 9-11 meters (29-36 meters) in length) and Ptychodus (which grew up to 10 meters (32 feet) in length). https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231544 https://www.cambridge.org/core/journals/journal-of-paleontology/article/morphology-and-paleobiology-of-the-late-cretaceous-largesized-shark-cretodus-crassidens-dixon-1850-neoselachii-lamniformes/A670012A44DDC68FC098BB8C73368408 The seventh is the Miocene-Early Pilocene (23-3.6 Million Years ago). This period saw the rise and reign of some of the largest sharks known currently in the fossil record, including Carcharocles (Otodus) megalodon (which grew up to 17 meters (55 feet) in length). https://www.uv.es/everlab/PUBLICACIONES/2017/2017 Martinez-Perez et al HB miocene sharks.pdf https://www.science.org/doi/10.1126/sciadv.abl6529 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9385135/ The eighth is the Early Pliocene-Late Pleistocene (3.6-0.012 Million Years ago). This period saw the last remnants of the large 20 foot + in size carnivorous sharks from the Miocene-Pilocene mega shark era not including the non-Great White shark (Carcharodon carcharias) and not including the large plankton eating sharks make their final stand. These include Hemipristis serra (which grew up to 6 meters (20 feet) in length) and Parotodus benedeni (which grew up to 7.6 meters (24 feet) in length). https://www.app.pan.pl/archive/published/app63/app004542018.pdf https://www.researchgate.net/publication/364591134_A_previously_overlooked_highly_diverse_early_Pleistocene_elasmobranch_assemblage_from_southern_Taiwan https://www.cambridge.org/core/journals/paleobiology/article/chondrichthyan-fossil-record-of-the-florida-platform-eocenepleistocene/2835CCEC27DC8EE0B24A5B62B1416618 I hope this is helpful?

I bought this rock online auction site. it was sold as a Permian Coprolite with bones from Oklahoma. it is 2 cm long. The last 5 images are microscopic. what do you think?

Hello, Could I get an ID on this piece? Permian-aged from the Ryan Formation near Waruika, Oklahoma. It's labeled as a reptile jaw piece. Has three teeth that are laterally compressed and somewhat twisted with serrations (Apparently there are serrations only on one side of the teeth). I wonder if it's shark and not reptile at all. Pathological shark tooth perhaps? Size is a little over 1cm. @jdp