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  1. Hello all, I’ve had this tyrannosaur tooth for a little while now, but haven’t been able to narrow down a species. I’m curious if it is possible to ID it any further. Would love to learn more. It was found in the Judith River Formation (Hill County, MT), and is ~13.5mm. Thank you all for your help in advance!
  2. Perhaps one of the most exciting scientific papers in a while about the genetic diversity of the Tyrannosaurid genus Tyrannosarus itself (the genus that includes the famous and well documented T-rex) was just announced and published (or at least the abstract of it)!!! Image Credit: Dalman et al. 2023 (abstract) and the Society for Vertebrate Paleontology (SVP). https://vertpaleo.org/wp-content/uploads/2023/10/2023_SVP_Program-Final-10032023.pdf At the Society for Vertebrate Paleontology's annual meeting for 2023, Paleontologists Dr. Sebastian Dalman, Dr. Philip J. Currie, and seven other experienced Paleontologists and experts on the Tyrannosaurid theropod dinosaurs published an abstract on October 21, 2023 about a new species of Tyrannosaurus (Tyrannosaurus mcraensis) from the Hall Lake Formation dating 72 Million Years ago to the Campanian-Maastrichtian Cretaceous of what is now New Mexico!!! This not only gives insights on the origins of the genus Tyrannosaurus, but validates previous hypothesis over the years (at least since 2013) that a unique giant Tyrannosaur from southern Larmidia (now Western North America) that lived during the Campanian-Maastrichtian Cretaceous!!! Names given to this animal over the years include Alamotyrannus brinkmani and Tyrannosaurus brinkmani. A Digital Reconstruction of the Tyrannosaurus species Tyrannosaurus mcraensis and it's size compared to an average Human, April 2022. Image Credit: Artist LancianIdolatry https://twitter.com/LancianIdolatry/status/1511016414252978182 This is especially true given for how long the debate has been raging on the Validity ofThe species Tyrannosaurus mcraensis was when fully grown the same size of the averaged size adults of the later Tyrannosaurus rex from the later Maastrichtian Cretaceous. By the look of things with the Paper and the experienced paleontologists and Tyrannosaur experts who authored it, it seems just by looking at its abstract it will be be far more through and accurate than the recent Gregory S. Paul Paper from 2022 and maybe even prove the validity of the debate Tyrannosaur species Tyrannosaurus vannus from the 70-66 Million Years ago dated Javelina Formation of what is now Texas. But I'm wondering if anyone has more information on this study and the potential of it's results?
  3. bockryan

    Petrified Wood

    From the album: Fossil Collection: DC Area and Beyond

    Petrified Wood Glasgow, MT Judith River Formation Late Cretaceous
  4. Today is my last day off before I go back to work and I was supposed to spend the day making fossil starter kits. I have a cold though and I do not want the kids to think that 12 million year old shark teeth gave them a cold lol I am pretty bored so I thought I would post about our Judith River dinosaur fossils and how we are going to get discuss this formation. I am really surprised how much I am enjoying learning about these dinosaurs and this will be a formation that we spend a good bit of time on. It must have had some very productive ecosystems and there is a great diversity here to discuss. The kids will also get to see some familiar dinosaur families while learning about species that are new to them. I think during adaptation related presentations, this formation lets us get into ecological niches and discuss how two Tyrannosaurids existed as did at least two species of Dromaeosaurids and a Troodonitd plus other predators including non dinos. That is a lot of hungry mouths so niche selection and adaptations become very important. THere is also a great diversity of herbivores in this formation. I love the Ceratopsians from this formation and the diversity gives my son a lot of artistic options. We currently have one tooth but by the time we present we will have a couple more I think. This allows us to present a few species and say the teeth are not diagnostic so the teeth could have belonged to one or more really cool looking horned dinosaurs. This also gives the kids knowledge that there other Ceratopsians besides Triceratops. This will also be the point where we introduce Dromaeosaurids. Raptors are just iconic and this formation gives us the chance to really hit on adaptations. We have a Saurornitholestes tooth and will soon have a Dormaeosaurid caudal vertebra. While not assigned specifically to Dromaeosaurus, the vert will presented that way so we can talk about the differences between the two raptors. Of particular interest is the larger skull, more robust teeth, and specific wear patterns on the teeth of Dromaeosaurus. We will also have a small tooth tip from a Tyrannosaur indet. The kids will love learning about other Tyrannosaurids and I will leave it to the kids to imagine which one it belonged to. The real owner of the tooth is not important. That two existed in this formation is what is important. They must have occupied different niches plus a lot of kids may think T-Rex was the only member of that family. The last fossil I know we will have from Judith River is one of my favorites. It is an Ankylosaurus tooth and thanks to some help from TFF members, I spotted this among a few Nodosaur teeth. In our inventory, this is Ankylosaurus indet. However, in every single dinosaur presentation we do this will be Zuul and it will be a rock star. We want the kids to understand that there are many new discoveries being made and there will be a lot of new dinosaur discoveries made by THEIR generation. Everything about Zuul will be cool to kids. It is the one of the most incredible fossils ever found, armored dinosaurs are just cool, and it even has a pop culture name that a lot of kids will recognize from Ghostbusters lol Only 5 fossils but we can do A LOT of quality education with these fossils. I also have a very clear idea of the next items to find from Judith River. #1 on that list is a Dromaeosaurus tooth. A tooth gives us the perfect way of illustrating the difference between the raptors. We have two more purchases to complete before I buy again so I will save up and in the spring I start searching for that tooth. I also would love to add a hadrosaur bone from this formation and eventually I will track down a frill piece. Anyway, here a couple of the fossils... Pic 1- our Saurornitholestes tooth. Not a great picture but a really nice tooth. Pic 2- the Dormaeosaurid indet vert. Not here yet but will be right around my B-day. Pic 3- the Anky tooth. It is just a cool tooth and Zuul is a great dinosaur to teach kids about so Zuul is what this tooth is for Fossils on Wheels. Our only fossil from an armored dinosaur.
  5. Frightmares

    Dromaeosaurus tooth?

    Purchased this tooth that was listed a theropod tooth. I think/hope it may be Dromaeosaurus. It has been repaired. From Hill County, MT, Judith River Formation. Seems to have a mesial carina twist & chisel shaped distal denticles. CH: 13mm CBW: 4mm CBL: 7mm Mesial: 5/mm Distal: 3/mm
  6. A new paper that describes Furcatoceratops elucidans a new centrosaurine ceratopsid from the Judith River Formation of Montana Unfortunately it's paywalled https://www.sciencedirect.com/science/article/abs/pii/S019566712300188X Anthony Maltese posted this This was the Ava skeleton Blog by A. Maltese http://rmdrc.blogspot.com/2015/02/avaceratops-layout.html Reposted by D. Evans
  7. Troodontids certainly are one of my favorite dinosaur families. Intelligent and what a set of chompers to eat you with, all you can ask for in a cool dinosaur. Will start this with the Pectinodon teeth in my collection and will continue to add as I take photos. This species has some of the coolest teeth. Pectinodon bakkeri is the only named Troodontid in the Hell Creek and Lance Formations. This is a tooth taxon and its teeth are significantly much smaller than its big cousin Troodon formosus. Lance Formation Hell Creek Formation A couple of the teeth in matrix are partially rooted which is extremely rare since the teeth are so small Hell Creek Formation - Powder River County Hell Creek Formation
  8. Consolidated all my informational Topics to make it easier to reference. Will keep updating since some of the reference material is outdated. Have to thank @PFOOLEY for suggesting this consolidation and it makes it a lot easier for me to access these topics as well as our members to know what's out there. General Tips in Buying Theropod Teeth Dinosaur Anatomy 101 Stratigraphy of the Late Cretaceous in North America Best Books for Dinosaur Identification Rare Theropod Teeth (World Wide) Identification of Some rarer Theropod Teeth Triassic Identification of Dinosaur Teeth from the Triassic of New Mexico Jurassic: Morisson Formation Identification of Theropod Teeth Quick Guide To Sauropod Teeth Tips in Buying a Sauropod Foot Claw Ornithischians from the Morisson Formation Jurassic: Europe Dinosaurs of Costal Portugal Jurassic Theropods of Germany Cretaceous: USA Hell Creek & Lance Formation Fanual List Identification of Theropod Teeth in the Hell Creek and Lance Formations Identification of Troodontid Teeth Identification of Tyrannosaurid Teeth From USA & Canada Identification of Ankylosaurid Teeth Identification of Acheroraptor Teeth Identification of Hadrosaur Teeth Identification of Claws and Ungals from the Hell Creek and Lance Formations Identification of Pachycephalosaurid and Thescelosaurus Teeth Tooth Features in Tyrannosaurids The Case for Nannotyrannus Dakotaraptor Teeth and Claws Hell Creek Fm Identification of Bones /Claws from Alvarezsaurids from North America Hell Creek Faunal Representation Identification of Theropod Teeth from Judith River Formation ( Campanian ) Includes Faunal List Fanual List from the Two Medicine Formations . Theropod Assemblage of New Jersey Cretaceous: Kem Kem of Morocco Kem Kem Theropod Teeth Kem Kem Theropod Tooth Morphology Identification of Sauropod Teeth from the Kem Kem Tips in Purchasing a Spinosaurid Hand Claw Identification of Claws from the Kem Kem Identification of Spinosaurid Jaws from the Kem Kem Guide to Help Purchase Rooted Moroccan Theropod Teeth Pterosaur Teeth from Kem Kem Republic of Niger Identification of Theropod Teeth Thailand Identification of Spinosaurid Teeth Cretaceous: South America Patagonia's Theropod Teeth Cretaceous: Uzbekistan: Identification of Theropod Teeth: Uzbekistan Sauropod Teeth: Uzbekistan Cretaceous: Europe Identifying Baryonyx Teeth
  9. ThePhysicist

    Judithian Theropod

    From the album: Dinosaurs

    A theropod tooth I recently acquired from the JRF. Sold as a juvenile Tyrannosaurid, but I'm not fully convinced.
  10. I purchased this tiny tooth from The Judith River Formation, North of Havre, MT found on a private ranch close to the border. I am unable to identify the tooth, it appears Thescelosauridae however I don't think Thescelosaurs have been found in Judith River. Measures 0.18" Any idea what this could be?
  11. Kikokuryu

    Tiny Judith River Theropod Teeth

    These teeth were sold as a baby tyrannosaurid and a dromaeosaurid/bird respectively. Some other specimens from this lot have been posted here if I recall. But they are from North of Havre, Montana close to the Canadian border. Apparently they are from quite an old collection from around 1950-70s. The provenance should place it solidly in Judith River Formation. Since these teeth were selling somewhat quickly, I just grabbed them and decided on figuring it out later. The first tyrannosaurid tooth does have some similarities to Dromaeosaurus with the mesial twist, but I could be wrong. The second tooth is a bit more confusing. I'm guessing it is Zapsalis-type with those striations which would make it Saurornitholestes. I don't think it's bird compared to bird teeth from other deposits. It's probably not one of those Campanian microraptorians either, and it's probably too big even at this size to be bird or micro. 1st tooth: Length=6.3mm; Distal Density=17.5/3mm; CBL=2.9mm; CBW=1.8mm 2nd tooth: Length=5.8mm; Distal Density= ±11-12/mm (?); CBL=2.6mm; CBW=1.3mm Serration density for the 2nd tooth might not be too accurate since it was extremely difficult to even get to that number. Not sure how to go about getting CH, but it's probably a little bit more than the length since the tips are worn. 1st tooth might be good as is since with that small root section, that probably makes up for what would be a longer crown. 1st Tooth 2nd tooth
  12. Edited 6/20/23: added Furcatoceratops elucidans More and more dinosaur material is becoming available from the Judith River Formation. I see lots of misidentified material and some with questionable localities that might fit other deposits. I would like to summarize what I believe is currently known and published. If you see any omissions or errors, please let me know. Not a lot of good maps out there to show the formation but here are two. In general, the exposures are in North Central Montana. Horner describes the formation on the western end is near the east end of the Sweetgrass Hills (very thick about 152 meters) and thins to less than 3 meters to its eastern edge Saco, MT. Bound by marine deposits Claggett Formation beneath and Bearpaw Fm above. More important, for collectors buying material is to be aware of the counties that have the majority of exposures they include but not exclusive to: Hill County, Blaine County, Phillips County, Western Part of Valley County, Fergus County, Wheatland County, Northern Valley County, Western Part of Garfied County, Big Horn County .You can see by the maps why a good provenance is vital to an ID. Stratigraphic range: Late Cretaceous, Middle to Upper Campanian 79.7 - 75.2 Ma Red _ Judith River Fm in Montana Faunal List: Updated 10/22/2022 (excludes Avialae) Lots of changes in recent years so older hard copy books are most likely out of date e.g. Dinosauria 2nd edition. This list was developed based on looking at a number of different reference sources, not Wikipedia, and like most lists some paleontologists or collectors may have different opinions, which is fine. The Judith deposit is very similar to those of the Belly River Group however you would not guess it by the variety of different dinosaurs that are described in this list particularly with the herbivores. Denver Fowler has even questioned if there is any justification to calling it Judith anymore since its continuous with Canadian Units. Will leave that for a different discussion since it probably will never happen. Edited 11/25/22 Tyrannosauridae: - Tyrannosaur indet. (Tom Holtz 2021) - Daspletosaurus wilsoni (Warshaw & Fowler 2022) - Aublysodon mirandus - nomen dubium Dromaeosauridae: - Dromaeosaurus albertensis (Matthew & Brown 1922) - Saurornitholestes sp. - Dromaeosaurid? - Zapsalis abradens (Although included on most faunal list this tooth morphology was shown to be a premaxillary tooth of a Saurornitholestes (DPF) (Currie & Evans 2019) it is therefore not valid Theropods: - Troodon formosus (Leidy 1856) - cf Richardoestesia gilmorei - cf Paronychodon lacustris - Ornithomimid indet. (spp.) - Ornithomimid large bodied (PO & Longrich 2007 DPFm) - Cenagnathid indet (Personal Observation) - Theropod indet Pachycephalosauridae: - Pachycephalosaurid indet. - Colepiocephale lambei (Sternberg 1945) Ankylosauria: - Nodosaurid indet (cf Edmontonia) - Zuul crurivastator (Arbour & Evans 2017) - Ankylosaurine ? Ceratopsidae: - Avaceratops lammersi (Dodson 1986) - Judiceratops tigris (Leidy 1856) - Medusaceratops lokii (Ryan et al. 2010) - Mercuriceratops gemini (Ryan et al. 2014) - Spiclypeus shipporum (Mallon et al. 2016) - Furcatoceratops elucidans (Hiroki Ishikawa et al. 2023) - Ceratopsid indet. - Leptoceratopsid indet? Hadrosauroidae: - Probrachylophosaurus bergei (Fowler & Horner 2015) - Brachylophosaurus canadensis (Sternberg 1953) - Hadrosaurinae indet. - Lambeosaurinae indet. - Corythosaurus sp. (Takasaki et al. 2022) Other Ornithischians: - Orodrominae indet? PO- Personal Observation in my collection Reference - Takasaki, Ryuji; Chiba, Kentaro; Fiorillo, Anthony R.; Brink, Kirstin S.; Evans, David C.; Fanti, Federico; Saneyoshi, Mototaka; Maltese, Anthony; Ishigaki, Shinobu (2022-10-23). "Description of the first definitive Corythosaurus (Dinosauria, Hadrosauridae) specimens from the Judith River Formation in Montana, USA and their paleobiogeographical significance". The Anatomical Record. doi:10.1002/ar.25097. ISSN 1932-8486 -Tom Holtz Theropod guild structure and the tyrannosaurid niche assimilation hypothesis: implications for predatory dinosaur macroecology and ontogeny in later Late Cretaceous Asiamerica (2021) Canadian Journal of Earth Science -Mallon JC, Ott CJ, Larson PL, Iuliano EM, Evans DC (2016) Spiclypeus shipporum gen. et sp. nov., a Boldly Audacious New Chasmosaurine Ceratopsid (Dinosauria: Ornithischia) from the Judith River Formation (Upper Cretaceous: Campanian) of Montana, USA. PLoS ONE 11(5): e0154218. doi:10.1371/journal.pone.0154218 -Sahni A. The vertebrate fauna of the Judith River Formation, Montana. Bull Am Mus Nat Hist. 1972; 147: 321–412. -Schott RK, Evans DC, Williamson TE, Carr TD, Goodwin MB. The anatomy and systematics of Colepiocephale lambei (Dinosauria: Pachycephalosauridae). J Vert Paleontol. 2009; 29: 771–786 -Longrich NR. Judiceratops tigris, a new horned dinosaur from the middle Campanian Judith River Formation of Montana. Bull Peabody Mus Nat Hist -Ryan MJ, Russell AP, Hartman SC. A new chasmosaurine ceratopsid from the Judith River Formation, Montana. In: Ryan MJ, Chinnery-Allgeier BJ, Eberth DA, editors. New perspectives on horned dinosaurs: the Royal Tyrrell Museum Ceratopsian Symposium. Bloomington: Indiana University Press; 2010. pp. 181–188 -Freedman Fowler EA, Horner JR (2015) A New Brachylophosaurin Hadrosaur (Dinosauria: Ornithischia) with an Intermediate Nasal Crest from the Campanian Judith River Formation of Northcentral Montana. PLoS ONE 10(11): e0141304. doi:10.1371/journal.pone.0141304 -Rogers RR. Sequence analysis of the Upper Cretaceous Two Medicine and Judith River formations, Montana: nonmarine response to the Claggett and Bearpaw marine cycles. J Sediment Res. 1998; 68: 615–631. -Fowler DW (2017) Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America. PLoS ONE 12(11): e0188426. https://doi.org/10.1371/journal. pone.0188426 -Dinosaurs under the Big Sky, Jack Horner, 2001 Mountain Press Publishing Co.
  13. Mochaccino

    Theropod, Bird, or something else?

    Hello, I'm asking about the following bone end. It's said to be from the "Judith River Formation North of Havre, MT". Seller thinks it might be a bird bone since it's hollow but doesn't look like theropod, what do you think? @Troodon confirmed it's not dinosaur and might be turtle, is there enough to tell? And how would one make that distinction?
  14. Opabinia Blues

    Judith River Ankylosaur Teeth

    Hi all, A bulk purchase of channel deposit material from the Judith River Formation of Montana has yielded these teeth, each of which appears to have some ankylosaurian affinities. I have read @Troodon’s guide on this very topic, but alas I still would like a second look at some of these teeth. I do not have the capacity to take very good macro photos, but I hope that these are passable at least for an initial glance. The scale of each tooth. The numbering on the bottom is centimeters while the numbering on top is in inches Tooth 1: I’m 99% sure this one is ankylosauridae Tooth 2: Might actually be Ceratopsid, but the presence of “denticles” is what’s making me post this one. Tooth 3: Ditto for this tooth, may be Ceratopsid, but we’ll see. Tooth 4: 80% sure this one is Nodosauridae with feeding wear. The opposing side has the distinctive “shelf” that gives the tooth a mitt look. Let me know if a picture of the other side is needed. Tooth 5: Also thinking nodosaur on this one, fairly confident Thanks everyone!
  15. Dino Dad 81

    Theropod Caudal Vert

    I figured as long as I'm asking about a 2" finger bone, I might as well throw in a 2" caudal vert This is from the Judith River formation, Hill County, Montana. Thank you!!
  16. Fossil Maniac

    Ankylosaur tooth or nodosaur tooth?

    Hello! I recently bought this ankylosaur tooth (in fact it arrived today) and I was wondering if it could be from a nodosaur. Thank you! (Judith river formation hill county Montana)
  17. Hi all, I recently acquired this Theropod indet. tooth speculating it might be a Dromaeosaurus albertensis. It was found in the Judith River Fm., is 0.72 inch long and serration count over 5mm is 20 mesial and 18 distal. It is a very stout tooth, so might as well be a Tyrannosaurid. It has a twist in the mesial carina and though denticles are very close in width, mesial ones are shorter, and the shape of denticles does not look classic Tyrannosaurid to me. I would like hear your opinions please.
  18. Identification of theropod teeth from the Two Medicine formation is always a challenge even for the more experienced collector. Sellers whether its a dealer or auction site also struggle with identifications and sometimes just shotgun it. So I decided to put this together as an quick aide in providing you some information. Among the sources used is the reference book Dinosaur Systematics by Ken Carpenter and Phillip Currie... its an excellent reference source. This aide is for the more common teeth collected and sold, not for more obscure theropods. I'm sure mistakes/omissions have been made, feel free to let me know. Tyrannosaurs: Tyrannosaurids in the JRF are not described but Daspletosaurus and Gorgosaurus are most likely present. Teeth should be described as Tyrannosaurid indet. Teeth around 4" are most likely Daspletosaurus sp. Teeth from the TMF are either Daspletosaurus horneri or Gorgosaurus sp. see tyrannosaurid topic for details Aublysodon a "nomen dubium" dinosaur and teeth being sold belong to one the other three Tyrannosaurs in these assemblages. They should also be labeled Tyrannosaurid indet. They are probably an early ontogenetic stage of these theropods in pre-maxillary teeth. Dromaeosaurids: Dromaeosaurus albertensis Denticles (serrations) exist on both the anterior and posterior (inside the curve) carinae. The ones on the anterior are smaller than the posterior ones. You should be able to see the differences. The easiest way to identify these teeth is that the anterior denticles starts twisting towards the center of the tooth. The serrations should look like these (scale .2mm) cf Saurornitholestes langstoni this is a very common tooth and small typically less than 1cm long. They are strongly recurved and sharply pointed, the cross-section of the base is rectangular and very compressed. The best way to identify these teeth is a great differences in size of the denticles, the posterior being larger. Also when observed under a scope the very tip of the denticles are hooked towards the tip of the tooth. The serrations should look like these (scale .2mm) Others: several of these have not been described and are prefixed as cf (similar to) cf Richardoestesia gilmorei these teeth are quite varied in shape and size and are also common. Some are straight and others are slightly recurved. Denticles are often limited to the posterior carina and individual denticles are minute. If the denticles are present on both carinae they are identical in size. The serrations should look like these (scale .2mm) cf Richardoestesia isoceles identical to R. gilmorei except they are elongated and form an isosceles triangle. This species along with the Paronychodon are currently under study and will most likely be described to a new taxon cf Paronychodon lacustris type teeth are flat on one side and usually bear three or more longitudinal ridges. The other side is convex and can be smooth or longitudinal ridges as well. Zapsalis teeth are similar to Paronychodon but its a tooth taxon and may be dubious. Zapsalis abradens is described from the JRF however recent publications from Alberta has shown this morphology to be premaxillary teeth of Saurornitholestes. Zapsalis is not a valid genus. Troodon formosus easily recognizable tooth. Denticles strongly hooked turned toward the tip. Pectiondon sp. a Troodontid but significantly smaller 6mm or less than Troodon teeth. Comb like denticles on posterior carina, lacking on the anterior side. Morph types isolated small theropod teeth are abundant in these assemblages. Morph types exist and determining the taxonomic affinities of these teeth is problematic. So be prepared to identify these teeth as theropod indet. Note: A lot of what I've described here requires a detailed examination of the serrations. The crisper they are on your tooth the better the opportunity you will have to identify them. Having some magnification capability helps.
  19. I have a few vertebrae I was hoping to get identified. These are 3 that I don't have any others that are alike. I tried to search online and the oval shaped one looks like possibly a Pachy but wasn't sure. These were all found on the Judith River Formation Montana, Hill County. first 4 is the one that I thought was Pachy, 2nd 4 I am not sure, 3rd 4 might be Hadrosaur?
  20. Hi everyone ! Got this tooth for a while . Currently labelled as indeterminate hadrosaur tooth size 0.68" from Hill county , Judith river formation . I wonder if we can ID to the species name ? note : This tooth have a denticles(?) on the edge of the tooth . Thank you in advance Guns
  21. These are a couple smaller vertebrae and a bone I found on the Judith River Formation, I was hoping to get an opinion on what dinosaur they would be from. Thanks.
  22. As I understand it there are three described Tyrannosaurs from the Two Medicine and Judith River Formations -- Albertosaurus, Gorgosaurus and Daspletosaurus. I have read that research done on teeth from these three Tyrannosaurs has concluded that isolated teeth are statistically impossible to assign to a specific genus because they are so similar. Now, I know that there are a number of form members that have quite extensive collections and have spent time and money studying these teeth, and it is my believe (having spent 35 years in the minerals exploration business) that private researchers probably know as much if not more than the academics. It has been my experience that academics rarely spend their own nickel buying their own equipment, conducting field work, and collecting specimens to conduct their research. I also know from first-hand experience that statistical evaluation alone can lead one down the wrong path and to the conclusion 'it needs more study.' While I am not a 'true' collector, my interests are hands-on fossil and mineral specimens that tell a story to interest kids in general science. My question is are there any general observations about Two Medicine and Judith River Formation theropod teeth that one might use to assign a probable genus to these teeth? It seems that assigning a genus to isolated teeth from the large adult theropods is quite possible, juvenile teeth seem more problematic -- but juvenile teeth are what I can afford. I would appreciate observations you might be willing to share.
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