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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. Updated Nov 25, 2022 Collectors, online sellers and some dealers periodically ask me to help them in the identification of tyrannosaur type teeth. So I thought I would put together a guide from Western North America (US/Canada) to help in identification. The following is the current understanding of those Tyrannosaurids described/known with the stratigraphic unit where they are found. If I missed any let me know. Albertosaurus sarcophagus : Horseshoe Canyon Formation cf Albertosaurus indet: Wapiti Formation Gorgosaurus libratus : Dinosaur Park Formation Gorgosaurus sp. or cf Gorgosaurus: Two Medicine Formation, Oldman Formation, Foremost Formation, Daspletosaurus horneri : Two Medicine Formation Daspletosaurus wilsoni: Judith River Formation Daspletosaurus torosus : Oldman Formation Daspletosaurus sp. or cf Daspletosaurus: Dinosaur Park Formation Dynamoterror dynastes: Menefee Formation Tyrannosaurus rex : Hell Creek Formation, Lance Formation, Frenchman Formation, Scollard Formation, Denver Formation, (Trex fossils are also known from: Livingstone Fm, Laramie Fm, McRae Fm, Willow Creek Fm) Tyrannosaurus sp.: Javelina Formation, Ojo Formation Nanotyrannus lancensis : Hell Creek Formation, Lance Formation cf Nanotyrannus : Frenchman Formation, Scollard Formation, Denver Formation Thanatotheristes degrootorum : Foremost Formation Tyrannosaurid indet. (spp): Judith River Formation, Mesaverde Formation (Group), Fruitland Formation, Aguja Formation Teratophoneus curriei: Kaiparowits Formation Lythronax argestes: Wahweap Formation Nanuqsaurus hoglundi: Prince Creek Formation Tooth Identification Aublysodon mirandus Premaxillary teeth, those without serrations. This dinosaur is considered nomen dubium and teeth ascribed to it belong to other Tyrannosaurs. Albertosaurus sarcophagus Probably the easiest to identify since its the only Tyrannosaurid described from the Horseshoe Canyon Formation. The most important item in acquiring one of these teeth is the provenance of where it was found. Alberta is not adequate to identify it. You need a specific locality like Drumheller or Tolman Bridge. BTW this is true for all the Tyrannosaurid's discussed in this topic. A disposition is also needed for all dinosaur teeth removed from Alberta. These teeth can get quite large from collection of SMM Gorgosaurus libratus (cf, sp.) The first step in identification is Provenance: you need to know State/Province along with the County (USA) or Locality (Canada) where the tooth was found. Differentiating isolated teeth between Gorgosaurus and Daspletosaurus is very difficult and in most cases its indeterminate. A paper that came out in 2005 which was authored by Phil Currie et al. studied isolated teeth from this period looking at tooth and serration morphology. Their conclusion was that "it is difficult to quantifiably distinguish these teeth reliably by taxon". Therefore identifying them as Tyrannosaurid indet. is the easiest approach in those faunas that Gorgosaurus may be present? There is a quantitative process described in a new paper that may help which will be discussed later. Please note that lots of collectors would like to use size to differentiate these teeth from Daspletosaurus. However Gorgosaurus teeth can get quite large as seen in this photo of a Maxilla with one tooth which is over 3 inches and located in the back of this jaw. Daspletosaurus horneri, D. wilsoni, D. torosus (cf, sp.) The first step in identification is Provenance: you need to know State/Province along with the County (USA) or Locality (Canada) where the tooth was found. A paper that came out in 2005 which was authored by Phil Currie et al. studied isolated teeth from this period looking at tooth and serration morphology. Their conclusion was that "it is difficult to quantifiably distinguish these teeth reliably by taxon". Therefore identifying them as Tyrannosaurid indet. is the easiest approach in those faunas that Daspletosaurus may be present? However, its reasonable to say that teeth over 4" are PROBABLY from a Daspletosaurus. There is a quantitative process described in a new paper that may help which will be discussed later. *****Since the Judith River and Two Medicine Formations fall within the range of all three of these species its going to be difficult to assign teeth to a specific species unless you know the age of the deposit it. Denver Fowler: "Hill County exposures are more easy to date because there we have the boundary between the upper Oldman Fm and the lower part of the Dinosaur Park Fm. Havre exposures were called Judith River Fm historically, but we should probably use Oldman & Dino Park now." And maybe ditto for those teeth found in the Belly River Group of Alberta. Denver Fowler "I expect that D. wilsoni is stratigraphically equivalent to the lower part of the Dinosaur Park Formation. At the moment this is based on the fact that the Judith in eastern Montana was deposited at the time when the WI seaway was receded at its maximum (in the Campanian)" Denver's response to my question on this subject. "There isn't currently any evidence for stratigraphic (time) overlap between the species. However, the 2Med and Judith River likely represent enough time such that it would be possible to find D. torosus in the Judith and both D. torosus and D. wilsoni in the 2Med." (Posted by Denver Fowler) Tyrannosaurus rex/ Nanotyrannus lancensis (cf, sp.) Whether you agree or disagree that Nanotyrannus is a valid taxon what is very clear to me is that we have two distinct morphologies of tyrannosaurid teeth at the very end,of the cretaceous. I can say that because I have handled over 1000 teeth over the years ranging from 3 mm to 5 inches two morphs are present in all ranges up to around 2 inches. Serration density through sampling I've done with teeth in my collection do not appear by itself to be a differentiator between these two morphologies. Density will change with size becoming less on larger teeth and can be the same with equivalent size teeth with both morphologies. DSDI (Denticle Size Difference Index) is also not a differentiator and through my sampling and Carr (2004) and indicates that DSDIs decrease in progressively larger specimens, that is, there are fewer mesial denticles per given unit length than distal denticles in large specimens and there are as many or more mesial than distal denticles in small specimens. Also, the DSDI among dentary teeth is higher than that in the maxilla, indicating that mesial denticles are smaller in the dentary than in the maxillary dentition. So how do you tell the difference between these two morphologies. Well, if a tooth is larger than 2 1/2" and has bulk its clearly T rex, regardless of what the serrations say. It cannot be anything else. With small teeth since serrations density is not a differentiator the other characteristic of the tooth plays a key role. I've found that maxillary teeth can be the most difficult to differentiate and a few teeth are just indeterminate, at least with me. The best way to distinguish between the two morphology the shape at the base, compression of the crown and tip and if there is a pinch at the base. Shape at the base T rex dentary teeth and the very anterior maxillary teeth are oval at the base while Nano teeth are unique as tyrannosaurids and rectangular. However, T rex maxillary teeth can be rectangular so you will have to determine if there is a pinch at the base a characteristic found on Nanotyrannus teeth Here are examples of the cross sections of couple small Rex teeth under 1 1/2 inch and Adult Nano's Tyrannosaurus rex Dentary teeth are oval Maxillary Teeth are rectangular Nanotyrannus Bases are rectangular and show a pinch on both sides. Profile of the teeth is another characteristic Nanotyrannus teeth are compressed, with a pointed tip T rex teeth are fat, with a rounded tip, often the serrations wrap around from the mesial to distal carina to form a continuous carina Crown Height Ratios In the study I did, since nothing is published, with 30 Nanotyrannus teeth the average was 2.2 For Trex teeth the mean for Maxillary teeth is 1.75 and for Dentary its around 2 but all these can change depending on position Heterodonty in Tyrannosaurus rex: implications for the taxonomic and systematic utility of theropod dentitions Joshua B. Smith (2005) T rex Premaxillary Teeth can easily be confused with dentary D1 position. Here is a photo of how to determine what you have. Identifying Gorgosaurus and Daspeletosaurus Teeth using Dental Features A recent paper by Hendrickx et al. (Oct 2019) has provided us a way to try to identify certain teeth using dental features. Positional Daspletosaurus & Gorgosaurus teeth have distinct denticle features that can hopefully can be used to differentiate the species which currently does not exist. Together with @Omnomosaurus we are looking at studying this technique to determine if its a practical method for collectors to use for identification, obtain data on campanian tyrannosaurid teeth and try to understand if the results we are getting is any good? We will be using teeth from my collection and members for the study. @dinosaur man has a topic where a lot of member data will be collected. Step 1 The most critical part in using this process is knowing where the tooth sits in the jaw - Premaxillary, Mesial or Lateral Here is a photo of to help in determining its location Paper https://www.researchgate.net/publication/261630184_Morphometry_of_the_teeth_of_western_North_American_tyrannosaurids_and_its_applicability_to_quantitative_classification Step 2 DSDI (Denticle Size Difference Index) needs to be determined DSDI = MC / DC MC = Number of denticles per 5 mm on the mesial carina at mid-carina DC = Number of denticles per 5 mm on the distal carina at mid-crown Mesial Carina is on the outer curvature Distal Carina is on the inside curvature Step 3 1) If your tooth is from a lateral position in the jaw and your DSDI is <0.8 your tooth may be considered a Gorgosaurus or cf Gorgosaurus depending on the locality of where it was found. 2) If your tooth is from a Mesial position in the jaw and your DSDI is >1.2 your tooth may be considered a Daspletosaurus sp. or cf Daspletosaurus depending on the locality of where it was found. Premaxillary Teeth 1) In my opinion all these teeth should be identified as "Tyrannosaurid indet" 2) The paper does make the following statement "In the young specimens of Daspletosaurus, the carinae of the premaxillary teeth are unserrated (TMP 1994.143.1; Currie, 2003) and show the beaded condition. My concern is that it does not specify what size young teeth are and its looking at TMP 1994.143.1 which is a Daspletosaurus sp in Dinosaur Park Fm. Do all Daspletosaurus premax teeth in other faunas have contain similar features? Gorgosaurus premax teeth are not mentioned. Study Currently 33 teeth from the collection of Troodon, Omnomosaurus, dinosaur man Localities included : Judith River Formation (18 teeth), Two Medicine Formation (13 Teeth), Dinosaur Park Formation (1 Tooth), One unknown Results: 1) None of the lateral teeth have had DSDI < 0.8 and could be described as Gorgosaurus 2) Three of the Mesial teeth had DSDI > 1.2 and could be described as Daspletosaurus 3) One of the Premaxillary teeth was not serrated but could not verify if it was a young tooth 4) So 9% of the population can be tentatively assigned Hendrickx et al paper https://palaeo-electronica.org/content/2019/2806-dental-features-in-theropods
  3. The two most prominent hypothesizes on the direct evolutionary origin of perhaps the most famous Theropod Dinosaur from the fossil record, Tyrannosaurus Rex (Tyrannosauridae, Late Cretaceous (68-66 Million Years ago)) are what I call the Laramidia and Asian Origins. The Laramidia origin (named after the region of the Western North America which was a separate Continent during most of the Late Cretaceous and home to a vast amount of dinosaurs including Tyrannosaurus rex) hypothesizes that Tyrannosaurus rex is the direct descendent of and evolved from slightly older North American Tyrannosaurids like Daspletosaurus (Tyrannosauridae, Late Cretaceous (79.5-74 Million Years ago)). Warshaw, Elías & Fowler, Denver. (2022). A transitional species of Daspletosaurus Russell, 1970 from the Judith River Formation of eastern Montana. PeerJ. 10. e14461. 10.7717/peerj.14461. https://www.researchgate.net/publication/365746599_A_transitional_species_of_Daspletosaurus_Russell_1970_from_the_Judith_River_Formation_of_eastern_Montana The Asian origin hypothesizes that Tyrannosaurus’s direct ancestor was a Tyrannosaurid from Asia. This supported by how closely related the Asian Tyrannosaurid Tarbosaurus (Tyrannosauridae, Late Cretaceous (70 Million Years ago)). This hypothesis further elaborates that a that the Asian Tyrannosaurids arrived in Western North America via a land bridge between what is now Eastern Russia and Alaska around 73-72 Million Years ago. On arrival, theses Asian Tyrannosaurids outcompeted and caused the extinction of most of the Native Tyrannosaur species of Laramidia (including Albertosaurus (Tyrannosaurid, Late Cretaceous (71-68 Million Years ago)), creating conditions allowing for the emergence of the genus Tyrannosaurus. Brusatte, Stephen & Carr, Thomas. (2016). The phylogeny and evolutionary history of tyrannosauroid dinosaurs. Scientific Reports. 6. 20252. 10.1038/srep20252. https://www.nature.com/articles/srep20252 Takasaki R, Fiorillo AR, Tykoski RS, Kobayashi Y (2020) Re-examination of the cranial osteology of the Arctic Alaskan hadrosaurine with implications for its taxonomic status. PLoS ONE 15(5): e0232410. https://doi.org/10.1371/journal.pone.0232410 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0232410 Both hypotheses have points that are supported by the fossil record, but still don’t fill all the gaps in answering the question of the direct origin of the genus Tyrannosaurus. There is however another hypothesis I have pondered over for at least the past few months which could fill in some (if not all) the gaps to this question. It is the Hybrid Speciation Origin hypothesis. The Hybrid Speciation Origin hypothesis basically states that after a land bridge formed between Eurasia and Laramidia during the Late Campanian stage of the Cretaceous (73-72 Million Years ago) and the Asian Tyrannosaurids arrived in Laramidia, certain individuals of a Asian Tyrannosaurid genus breed with a species of a genus of Native Laramidia Tyrannosaurid (likely a direct descendent of Daspletosaurus). Enough of these inter-genus breeding events occurred that a new Tyrannosaurid genus distinct from its parent species (and genuses) emerged around 68 Million Years ago, Tyrannosaurus. I will admit this would be extremely difficult to prove, but I do believe it could be a valid hypothesis. It corroborates the many similarities in skeletal structure Tyrannosaurus shares (and how closely related it is phylogenetically) with the Asian Tyrannosaurid Tarbosaurus and the skeletal structure similarities and general body shape it shares with Daspletosaurus. Image Credit: https://www.nature.com/articles/srep20252 Brusatte, Stephen & Carr, Thomas. (2016). The phylogeny and evolutionary history of tyrannosauroid dinosaurs. Scientific Reports. 6. 20252. 10.1038/srep20252. https://www.nature.com/articles/srep20252 Warshaw, Elías & Fowler, Denver. (2022). A transitional species of Daspletosaurus Russell, 1970 from the Judith River Formation of eastern Montana. PeerJ. 10. e14461. 10.7717/peerj.14461. https://www.researchgate.net/publication/365746599_A_transitional_species_of_Daspletosaurus_Russell_1970_from_the_Judith_River_Formation_of_eastern_Montana Stein, Walter W.; Triebold, Michael (2013). "Preliminary Analysis of a Sub-adult Tyrannosaurid Skeleton from the Judith River Formation of Petroleum County, Montana". In J. Michael Parrish; Ralph E. Molnar; Philip J. Currie; Eva B. Koppelhus (eds.). Tyrannosaurid Paleobiology. Bloomington: Indiana University Press. pp. 55–77. Currie, P.J. (2003). Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada. Acta Palaeontologica Polonica 48 (2): pp. 191–226. https://www.app.pan.pl/archive/published/app48/app48-191.pdf I am interested in how the tyrannosaurid species Nanuqusaurus (Tyrannosaurid, Late Cretaceous (70-68 (likely also to 66) Million years ago), the Daspletosaur Tyrannosaurid specimen RMDRC 2002.MT-001 “Sir William”, and the Tyrannosaurid specimen CM 9401 could factor into the validity of the hybrid speciation hypothesis. I hold no illusions in thinking this hypothesis is not going to be controversial. But I do think it could be semi plausible. What do you guys think?
  4. The Twitter Paleontology World post cool images of fossils on Friday so I'm happy to steal from them and share some dinosaur ones with this forum Holotype specimen of the short-faced dromaeosaur Atrociraptor from the Horseshoe Canyon Fm of Alberta - ROM Oviraptorid Skull, Mongolia, Rinchenia mongoliensis AMNH Protoceratops andrewsi 3 Year old Tarbosaurus, Mongolia Skeleton of Baryonyx Amargasaurus, from Museo Paleontológico Egidio Feruglio, Patagonia, Argentina is a Sauropod. Diabloceratops holotype skull natural history museum of Utah Daspletosaurus maxilla -Tyrrell
  5. Hello. I was wondering if anyone could help me identify this tyrannosaur tooth I recently added to my collection. It is said to be from the Judith River formation in North-Central Montana. Unfortunately, I don't have the county it came from. The tooth has the following measurements. Thanks for your help. CH = 40 mm CWB = 10 mm CBL = 16 mm MC = 18 denticles/5 mm DC = 14 denticles/5 mm DSDI = 1.29
  6. Hello, this tooth has baffled me for years. I can't tell if it is a juvenile tyrannosaurid dentary tooth or a cf. Richardoestesia gilmorei tooth Its locality info is Montana, Two Medicine Formation The tooth has a serration density of 19/5mm on the distal mid-line. Unfortunately the mesial carina is worn down so that crucial data is missing The CH is 11.5 mm, CBW is 7 mm and CBL is 4.5 mm As far as I am aware, juvenile tyrannosaurid (with the exception of T. rex) have slender teeth while as this tooth is somewhat robust. Meanwhile, Richardoestesia gilmorei is somewhat of a wastebasket ID for many teeth(likely unrelated species), so this teeth should fall into the range of size and morphology for one May I have your thoughts on this tooth?
  7. Darwin and Wallace

    Need ID for Two Medicine Tyrannosaur teeth

    Hello all, I need some help ID'ing these two tyrannosaur teeth from the Two Medicine Formation in Montana. Does anyone know how to tell the difference between Gorgosaurus and Daspletosaurus teeth based on this size? Thanks for any help.
  8. So over the past few days I was visiting Bozeman from Raleigh North Carolina as I was visiting the MSU campus because I've been accepted to start as a freshman in autumn 2021. And I hope you know what I am trying to major in. I mean you know what forum we're on I don't have to spell it out. Anyway, in that time I managed to spend all day visiting the Museum of the Rockies which is considered one of the Mecca halls for paleontology. Our crazy old boi Jack used to be Prof and curator there before... well you know. My home museum, the NC Museum of Natural Sciences are taxonomic lumpers when it comes to paleontology but they are passive lumpers. They are nothing compared to what the MOR has going on holy snarge I was surprised. I like going to different museums like this because it shows different perspectives based on findings that vary by institution. While I don't agree with a lot of it, it's healthy to expose oneself to different ideas and conclusions. Also I just couldn't help but feel giddy in the midst of all these dinosaurs. I'll update this post with pictures in a few moments... I will also post what the info cards on the exhibits state about each specimen. Here is Big Mike. A metal replica of MOR 555 commonly known as the Wankel although now more known as the Nation's T. rex since the og skeleton's move to the Smithsonian. I spent at least 30 minutes admiring the sculpt of this beautiful beast alone. Our first is a tibia of a Hadrosaur indet. found in 80 mya rock in Chotaeu, Montana so likely the Two Medicine Formation however this is unique because this is from it's lower strata which we don't know much about that's why it isn't identified as Maiasaura, as that dinosaur lived later. Here are some nice trace fossils and geology stuff, Here's the Precambrian globe Here's how sediments move through time. There's dioramas too. Starting with the Cambrian of course with Anomalocaris and working our way up. Here we're getting some Ordivician and Silurian description, Devonian like creatures. Although Coelocanths first evolved 400 mya they live all the way up to the present day. Stethocanthus below Next we start going in depth into the dinosaurs more updates coming stay tuned...
  9. I’m not sure if this has already been shared or not but a recent paper discussing the braincases of two Daspletosaurus specimens show more variation then previously thought. from the paper: “For sheer complexity, braincases are generally considered anatomically conservative. However, recent research on the braincases of tyrannosaurids have revealed extensive morphological variations. This line of inquiry has its root in Dale Russell’s review of tyrannosaurids in which he established Daspletosaurus torosus — a large tyrannosaurine from the Campanian of southern Alberta. In the wake of systematic revisions to tyrannosaurines previously assigned to Daspletosaurus, one potentially distinct species remains undescribed. This paper describes and compares a braincase referable to this species with that of the holotype for Daspletosaurus torosus using computerized-tomography-based reconstructions. The two braincases have numerous differences externally and internally. The specimen of Daspletosaurus sp. has a bottlenecked olfactory tract, short and vertical lagena, and a developed ascending column of the anterior tympanic recess. The holotype of Daspletosaurus torosus has many unusual traits, including an anteriorly positioned trochlear root, elongate common carotid canal, distinct chamber of the basisphenoid recess, asymmetry in the internal basipterygoid aperture, and laterally reduced but medially expanded subcondylar recess. This comparison also identified characters that potentially unite the two species of Daspletosaurus, including deep midbrain flexures in the endocasts. However, many character variations in the braincases are known in other tyrannosaurids to correlate with body size and maturity, or represent individual variations. Therefore, taxonomic and phylogenetic signals can be isolated from background variations in a more comprehensive approach by using additional specimens. New information on the two braincases of Daspletosaurus is consistent with the emerging view of tyrannosaurid braincases as highly variable, ontogenetically dynamic character complexes.” the paper: https://cdnsciencepub.com/doi/10.1139/cjes-2020-0185
  10. Hello again. I saw this supposedly Daspletosaurus tooth, said to be from the Two Medicine Formation, Montana. It measures approximately 1.5 inches. If you could help me, I would appreciate it. Thanks
  11. Hello again. I saw this tooth on the internet, I don't know what dinosaur it could be from. In the description of the publication it does not say anything, only that it is from the theropod and from the United States. I suspect it is from a tyrannosaurid, but which one? I don't know. Gorgosaurus? or T rex? There is no further information on the origin or training where it was obtained. What do you think it could be? I know that with so little data not much can be done, but I would like to know the opinions or suggestions that you have on this matter anyway, so that I can have a better idea and decide whether to buy it or not.
  12. Hi everyone, So I came across a tooth that says this tooth comes from a carnivore (Gorgosaur/Daspletosaur), is 3.81 cm in length. The seller is a Daspletosaurus, but you know, before buying anything I have to ask your opinion. It was found in the Two Medicine Formation. There was a debate as to whether it was either a Gorgosaurus or a Daspletosaurus. So the questions are: Is it a Daspletosaurus or a Gorgosaurus? In what condition it is?
  13. dinosaur man

    My Tyrannosaur research

    Hi I decided to make a post about my main research project right now on Campanian Tyrannosaurs specifically Daspletosaurus. Today I have found something to tell teeth from the Judith River Formation and Dinosaur Park Formation. This could also do with the Tyrannosaurs prey or locality. I found out that Judith River Formation Tyrannosaur teeth serrations are more circular and more round compared to the same time Dinosaur Park Formation Tyrannosaur teeth serrations. The Dinosaur Park Formation Tyrannosaur teeth serrations are more longer skinner and more chiseled like but not like other Tyrannosaur teeth from other areas like T. rex’s teeth serrations. Certain Tyrannosaurs in different areas and times would/could of had unique serration morphology probably dew to there prey. I did this on multiple teeth from the Judith River Formation and Dinosaur Park Formation to strengthen my hypothesis. Any opinions on this topic would be great. I will post more on my research here on this and other topics on the Tyrannosaur/Daspletosaurus. I have been doing research on this Daspletosaurus from the Dinosaur Park Formation and it’s close relatives because it was the first dinosaur fossil I’ve ever found. I’ve liked fossils and dinosaurs since I was 2 but in 2018 I went to Alberta and found my first dinosaur fossil which was a fossil from the Dinosaur Park Formation Daspletosaurus sp. Thats why I have been researching on this topic. The serrations I found on Dinosaur Park Formation Tyrannosaur teeth. The serrations I found on Judith River Formation Tyrannosaur teeth.
  14. dinosaur man

    Daspletosaurus drawing

    I recently just finished a drawing that took me a few weeks of the Daspletosaurus specimen FMNH PR308 and just wanted to share it.
  15. Top Trilo

    Tyrannosaur tooth ID

    I bought this tyrannosaur tooth a while back and it says it’s a albertosaurus, gorgosaurus, or daspletosaurus. Is there anyway to narrow it down any further? It says it was found in the Judith river formation of eastern Montana and it measures just over an inch. Any and all help is appreciated.
  16. MedicineHat

    Tyrannosaur teeth variations

    My son found a long skinny tyrannosaur tooth on South Saskatchewan River, West of Medicine Hat (oldman formation? Formost FM? DPP?) We've found all sorts of tyrannosaur teeth - short fat ones, short wide narrow ones, long fat ones, long narrow ones (Richadoestia), and all sorts of variations of curves or straight Species, age, and tooth position may all be factors. I'm just wondering if anyone has more info? This tooth is relatively narrow and thin for its length. I can post other examples of teeth found in the same area that are quite different from one another. I believe these may be examples of gorgosaurus or daspletosaurus as they were found in the DPP formation
  17. Troodon

    New Tyrannosaurid from Alberta

    Well it was about time but we have a new Tyrannosaurid from the Foremost Formation of Alberta called Thanatotheristes degrootorum. Its part of a new clad called Daspletosaurini which comprises other Daspletosaurus spp. The foremost is a mid Campanian deposit. Its the first described Tyrannosaurid from this deposit. This represents the earliest stratigraphic occurrence of diagnostic tyrannosaurid material from Canada. Its a paywalled paper https://www.sciencedirect.com/science/article/pii/S0195667119303611 From Wiki
  18. Hi just got these two fossils today! And was wondering did I get it right on saying this Daspletosaurus tooth was a mesial tooth? Also i called it a Daspletosaurus because it’s DSDI was over 1.2 and I think it’s a mesial tooth. In the photo it’s beside my smaller Judith River Tyrannosaur indet tooth. Also is it possible to tell what this dinosaur finger bone is? Thank you! dinosaur finger bone
  19. Roby

    Daspletosaurus Tooth

    Found in over a dozen pieces. Had repaired after I glued it back together.
  20. Hi I heard there are two Judith River Formation Daspletosaur species, an earlier one and older, is this true? Because the Daspletosaurus specimen Sir William being an older species from 79 to 77.5 mya and possibly D.torosus, D.honeri or another new species being the younger Daspletosaur species from 77.5 to 75 mya. Or is it just one Daspletosaurus in the Formation?
  21. dinosaur man

    My largest dinosaur tooth yet

    I just got this and it will be arriving soon, It will be my largest dinosaur tooth yet once It comes. It’s a Tyrannosaur indet for now and it’s from the Judith River Formation. Just wanted to share this. I wanted to share more information compared to my other topic.
  22. dinosaur man

    DSDI between 0.8 and 1.2

    Hi I have a question, I went back since I had some time and re measured my Tyrannosaur tooth denticles. But there both the same size, the Mesial and Distal are both 6. And the DSDI is 1, what would this mean? Thank you!! @Omnomosaurus, @Troodon
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