Troodon Posted March 22, 2018 Share Posted March 22, 2018 A number of collectors are very interested in Triassic Dinosaur tooth material, however, lots of misinformation exists, partially because little is known and dealers want to sell product. My knowledge is very limited so I tried to put together an assemblage of current information that has been published so that we can all become better versed on this topic. I'm not saying its complete but its the best I can do with my limited knowledge. Most technical papers on this subject are outdated, difficult to read for a novice and not complete enough. Fortunately a recent, legible paper was published in 2015 by Heckert & Lucas that has helped me. I've tried to extract the pertinent information, associated with teeth, since that what most collectors are interested in. First let me get on my sandbox and say that we should NOT assume that what is being sold is accurately described regardless who is selling it or how much you like a dealer. Very little is known and even less is described. If a seller insists what he has identified is accurate, have him show you the technical documents that supports his diagnosis. There are a number of theropods and archosaurs in these assemblages that have serrated teeth so identification is difficult. Triassic dealers similar to those in the Kem Kem which label everthing Spinosaurus like to label everything Coelophysis. Just be cautious..its your money. Almost all the teeth you see sold come from New Mexico so I will focus in that region. A Map of New Mexico with the Triassic outcrops shown below as well as the associated Counties. The numbers correlate to the stratigraphic formations shown below in Figure 4. Figure 4 The Zuni Mountains in West-Central NM are from the lower Chinle Group (Bluewater Creek Fm) and contain Tetrapod fossils amphibians and phytosaurs and aetosaurs. Dinosaurs are possible but nothing is diagnostic. Faunal List of the lower Chinle Group Zuni Mountains Northern/West Central New Mexico has yielded some of the most interesting Vertebrate Fossils most associated with Coelophysis at Ghost Ranch. Included in this group are the Petrified Forest and Rock Point Formation of the western counties. Chindesaurus bryansmalli, Tawa hallae and Daemonosaurus chauliodus are considered valid a dinosaurs in the Petrified Forest Fm. Coelophysis bauri is valid from the Rock Point Formation. Faunal List of the Petrified Forest and Rock Point Formation - Key on this list is Coelophysis bauri in the Rock Point Fm Northeasten New Mexico (Bull Canyon and Redonda Formations). Heckerts 2015 paper comments that dinosaur fossils remains are rare in the Bull Canyon Formation. The coelophysoid Gojirasaurus quayi has been described but its taxonomic placement is uncertain. Herrerasauridae tooth fragments have been found but nothing has been assigned to a taxon. Heckerts & Lucas 2015 Paper on Triassic Vertebrate Paleontology in New Mexico https://libres.uncg.edu/ir/asu/f/Heckert_Andrew_triassic.pdf Bull Canyon Formation 2001 Paper on Vertebrate Fauna https://nmgs.nmt.edu/publications/guidebooks/downloads/52/52_p0123_p0151.pdf Latest placement ( Hans-Dieter Sues et al 2011 ) Coelophysis bauri Formation: Petrified Forest (Chinle Formation) Location: New Mexico, USA Other occurrences: cf Coelophysis may be found in other late Triassic exposures Characteristics: Most all the teeth are recurved Lots of variation is seen in these dentition Some mesial teeth have only distal denticles. Fluted ridges can be see on juveniles The enamel surface texture is braided Marginal and transverse undulations appear to be absent on most crowns.. Premaxillary teeth: rounded cross-section, smaller teeth are ribbed but smooth on larger ones. None show serrations. Maxillary Teeth: the first tooth is recurved with no serrations, second tooth has serrations only on the posterior carina. All the other maxillary teeth have serrations on both edges. Some of the teeth the serrations may be limited to the upper part of the anterior (mesial) edge. Dentary Teeth: the first seven teeth lack serrations, eight tooth serrations only on the posterior edge. Subsequent teeth have serrations on both edges. The first four teeth are elliptical (rounded) in cross-section being compressed after that. Measurements: (From Hendrickx 2019 study) (2 Premax, 15 Maxillary, 3 Dentary) (Not all crowns had serrations) Dentary Density: 40 to 45 / 5mm (Avg 40.0 / 5mm) Maxillary Density: 35 to 50 / 5mm (Avg 15 / 5mm) Average Ratio's: Premax CHR: 3.6, CBR: 0.4 Maxillary CHR: 1.6, CBR: 0.4 Dentary CHR: 2.4, CBR: 0.5 The Museum of Northern Arizona publication Coelophysis describes the teeth as follows: Distal Carina Denticles (Source on colored images C. Hendrickx) Skull characterized by fluted teeth in juveniles, procumbent mesial dentary and maxillary teeth. Also some unserrated mesial crowns Some mesial teeth have only distal denticles. The mesial carina is straight and extends well above the root in lateral teeth. The enamel surface texture is braided and marginal and transverse undulations appear to be absent on most crowns.. (2 photos) Fluted ridges can be see on juveniles Additional images Premaxillary, Maxillary and Dentary teeth shown - Striations visible Anterior maxillary tooth #2 Maxillary Tooth #4 Maxillary tooth #10 Maxillary denticles M#5 Dentary tooth Posterior Maxillary Tooth Paper on Coelophsis Teeth by Currie and Buckley Coelophisis.pdf Additional images of the teeth with no supporting info Good overall paper on C. bauri but does nothing to increase our knowledge on how to describe its teeth https://www.researchgate.net/publication/292525024_The_paleobiology_of_Coelophysis_bauri_Cope_from_the_Upper_Triassic_Apachean_Whitaker_quarry_New_Mexico_with_detailed_analysis_of_a_single_quarry_block Ken Carpenter described these teeth from the Bull Canyon fm as cf Coelophysis. A few skulls Other Theropods Gojirasaurus quayi : one tooth was described with the holotype however it was found isolated and cannot be positively assigned to this species. (Added a few pages below) Chindesaurus bryansmalli : not aware of any skeletal material Daemonosaurus chauliodus Characteristics: Characterized by 3 large premaxillary teeth, first 2 dentary teeth are procumbent, longitudinal ridges on the crowns, some constricted teeth, and hooked mesial denticles A Premaxillary Teeth #3 B Maxillary Teeth C Posterior most Maxillary Teeth Reference on Daemonosaurus: The osteology of the early-diverging dinosaur Daemonosaurus chauliodus (Archosauria: Dinosauria) from the Coelophysis Quarry (Triassic: Rhaetian) of New Mexico and its relationships to other early dinosaurs STERLING J. NESBITT and HANS-DIETER SUES http://rspb.royalsocietypublishing.org/content/royprsb/278/1723/3459.full.pdf Tawa hallae : http://www.thefossilforum.com/applications/core/interface/file/attachment.php?id=503864 Characteristics All preserved premaxillary, maxillary and dentary teeth seem to be fluted on both sides Premaxillary are unserrated Maxillary teeth with a mesial denticulated carina reaching the root Interdenticular sulci present on both mesial and distal edges Teeth are very pointy Fifth? left maxillary tooth Scale: 1 cm images from C. Hendrickx twitter feed 34 Link to comment Share on other sites More sharing options...
Haravex Posted March 22, 2018 Share Posted March 22, 2018 Thank you troodon this is amazingly helpful to someone who has a passion for the early dinosaur forms. Link to comment Share on other sites More sharing options...
ynot Posted March 22, 2018 Share Posted March 22, 2018 Great information Frank! Thanks for taking the time to put this together. 1 Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
sixgill pete Posted March 22, 2018 Share Posted March 22, 2018 Great information Frank. 1 Bulldozers and dirt Bulldozers and dirt behind the trailer, my desert Them red clay piles are heaven on earth I get my rocks off, bulldozers and dirt Patterson Hood; Drive-By Truckers May 2016 May 2012 Aug 2013, May 2016, Apr 2020 Oct 2022 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted March 22, 2018 Share Posted March 22, 2018 Very useful. A good post indeed. Thanks, Frank. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Jaimin013 Posted March 25, 2018 Share Posted March 25, 2018 Thanks this will be useful in the identification of my so called Coelophysis bauri Triassic teeth that I will have acquired next month Link to comment Share on other sites More sharing options...
doushantuo Posted March 25, 2018 Share Posted March 25, 2018 Always nice to be credited for first posting a useful bit of information..... need i post this,anyone? 6 Link to comment Share on other sites More sharing options...
SULLY Posted March 26, 2018 Share Posted March 26, 2018 I love this group! Link to comment Share on other sites More sharing options...
Malone Posted March 26, 2018 Share Posted March 26, 2018 Again generations will benefit from your efforts! Link to comment Share on other sites More sharing options...
JohnBrewer Posted March 26, 2018 Share Posted March 26, 2018 Just love it when you make these types of posts Frank! 2 John Map of UK fossil sites Link to comment Share on other sites More sharing options...
Troodon Posted July 12, 2018 Author Share Posted July 12, 2018 The Tooth in the photo from the Bull Canyon Formation is often sold as Coelophysis or cf Coelophysis. I purchased it so I could study it and determine if its Coelophysis or dinosaurian. I compared my tooth to those in the study from Buckley/Currie 2014 paper on Coelophysis bauri dentition, the link "Coelophysis" is above. My overall assessment is that the tooth does not appear to be Coelophysis or cf Coelophysis and I question if its dinosaurian. The paper looked at key features Coelophysis Teeth are laterally compressed and recurved. You can see in the photo that the base bows out and its not compressed. Most theropod teeth do not bow out at the base. The tooth is however properly recurved. I then just looked at specific dimensions of the teeth in the study and stopped after these three since I had what I needed. My tooth is most likely a Dentary position but looked at all positions to be safe. Crown Height: (mm) Pre-Maxillary (sample 42) Minimum 1.1 Maximum 9.7 Maxillary (sample 181) Minimum .7 Maximum 11.4 Dentary (sample 71) Minimum .6 Maximum 8.2 My Tooth 16 mm well exceeds maximums FABL (Fore Aft Basal Length): (mm) Pre-Maxillary (sample 59) Minimum .7 Maximum 3.7 Maxillary (sample 311) Minimum .6 Maximum 6.3 Dentary (sample 184) Minimum .5 Maximum 4.4 My Tooth 6.0 mm at maximum for maxillary teeth CBW (Crown Base Width): (mm) Pre-Maxillary (sample 16) Minimum .5 Maximum 3 Maxillary (sample 60) Minimum .4 Maximum 2.4 Dentary (sample 34) Minimum .7 Maximum 1.7 My Tooth 5.5 mm width of tooth at base far exceeds maximums Based just on the size characteristics the tooth does not appear to fit into the population sampled in the paper Density 5.7 serrations per mm, midline distal edge which is low should be above 7. @Jaimin013 @Meatasaurus93 10 Link to comment Share on other sites More sharing options...
Meatasaurus93 Posted July 12, 2018 Share Posted July 12, 2018 4 hours ago, Troodon said: The Tooth in the photo from the Bull Canyon Formation is often seen sold as Coelophysis or cf Coelophysis. I purchased it so I could study it and determine if its Coelophysis or dinosaurian. The information I used came from Buckley/Currie paper 2014 on Coelophysis bauri dentition, the link "Coelophysis" is above. My overall assessment is that the tooth does not appear to be Coelophysis and I question if its dinosaurian. @Jaimin013 @Meatasaurus93 Hm, interesting analysis. As you already know, I picked up a similar tooth from the same seller. How do you feel about it possibly coming from some type of Rauisuchian? Link to comment Share on other sites More sharing options...
Troodon Posted July 12, 2018 Author Share Posted July 12, 2018 5 hours ago, Meatasaurus93 said: Hm, interesting analysis. As you already know, I picked up a similar tooth from the same seller. How do you feel about it possibly coming from some type of Rauisuchian? It's possible they have serrated teeth. This is the Bull Canyon Fm faunal list from the 2015 paper in the first page and the candidates. Not much is really described. Unfortunately very little is published and what is available rarely describes teeth. 3 Link to comment Share on other sites More sharing options...
Troodon Posted July 12, 2018 Author Share Posted July 12, 2018 Another morphology of tooth that you see sold as Ceolophysis is much smaller and upright, around 5 mm. I happen to have a few so decided to analyze them. My conclusions on this tooth is identical to the last one, do not believe it to be Ceolophysis or dinosaurian for the reasons stated below. The among the key features that characterizes a Coelophysis tooth is its recurved and laterally compressed. This tooth fails in both those areas and my primary reason for saying this not Coelophysis The distal edge on these teeth is close to perpendicular to the base. The cross-section of the base looks more like "S" in figure 5 below than what it should be "I thru L". That "S" cross-section continues into the face of the crown. . While the physical characteristics as far as height, width and density fit into the study group all of the teeth the identical in shape which was odd. When viewed under a microscope the denticles were a bit different that I would expect and did not see to fit. 3 Link to comment Share on other sites More sharing options...
Troodon Posted July 12, 2018 Author Share Posted July 12, 2018 Don't despair my fellow Bull Canyon Collectors I did find some gold in that grouping of teeth that I was looking at for the above post. Came across this tooth and without question its theropod and fits all of the characteristics that I would call Coelophysis : Its recurved, its laterally compressed, and the serration density is high. So they are there you just have to select among the rest of the tiny teeth. Laterally compressed Serration density +9/ mm difficult to call 8 Link to comment Share on other sites More sharing options...
Cowboy Paleontologist Posted July 18, 2018 Share Posted July 18, 2018 The lack of descriptions for teeth from the Triassic of New Mexico has really been an issue for me. If it is not Coelophysis or phytosaur, there is almost no hope to get a proper identification. Link to comment Share on other sites More sharing options...
Troodon Posted July 18, 2018 Author Share Posted July 18, 2018 32 minutes ago, Cowboy Paleontologist said: The lack of descriptions for teeth from the Triassic of New Mexico has really been an issue for me. If it is not Coelophysis or phytosaur, there is almost no hope to get a proper identification. Currently you are correct and that is especially true of material from the Bull Canyon Fm since little is described.. Having said that you may be able to see affinities Coelophysis bauri teeth from formations other than the Rock Point and identify them "cf Coelophysis" but most true theropod teeth will be Theropod indet. 1 Link to comment Share on other sites More sharing options...
SULLY Posted July 18, 2018 Share Posted July 18, 2018 Great thread! Thank you Link to comment Share on other sites More sharing options...
Troodon Posted August 1, 2018 Author Share Posted August 1, 2018 Gojirasaurus quayi A large coelophysoid from Bull Canyon Formation. This was the only tooth they found with the holotype. Cannot be positively assigned to it. The paper also illustrates vertebrae and other elements. Giant_coelophysoid_theropod.pdf Characteristics: Crown height: see illustration Serration density: 6/mm midline, 4/mm tip its less dense than Coelophysis Distal carina extends to the base Mesial carina extends half way down the crown Very compressed crown Shape of Denticles "B" in illustration. "C" is Coelophysis @Jaimin013 @Cowboy Paleontologist @Meatasaurus93 @TyBoy 9 Link to comment Share on other sites More sharing options...
Jaimin013 Posted August 3, 2018 Share Posted August 3, 2018 Thanks for the pics and the info! Link to comment Share on other sites More sharing options...
The Amateur Paleontologist Posted August 26, 2018 Share Posted August 26, 2018 On 22 March 2018 at 8:04 PM, Troodon said: Tawa hallae : paper is paywalled http://science.sciencemag.org/content/326/5959/1530 Challenge accepted Found the full paper without having to pay.. if anyone's interested, here it is: Nesbitt et al. 2009 Tawa.pdf By the way, I absolutely love this thread, @Troodon Thanks for these informative posts you make -Christian 4 Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
Troodon Posted August 26, 2018 Author Share Posted August 26, 2018 20 minutes ago, The Amateur Paleontologist said: Challenge accepted Found the full paper without having to pay.. if anyone's interested, here it is: Nesbitt et al. 2009 Tawa.pdf By the way, I absolutely love this thread, @Troodon Thanks for these informative posts you make -Christian Appreciate all the help I can get. I added your link to the above thread. Thank you 1 Link to comment Share on other sites More sharing options...
Bobby Rico Posted August 26, 2018 Share Posted August 26, 2018 This is a fantastic . Really helps us out . I am hoping to start a small Triassic collection . Thanks Frank Link to comment Share on other sites More sharing options...
Troodon Posted August 26, 2018 Author Share Posted August 26, 2018 I've attached illustrations of two Coelophysis bauri skulls to obtain a good perspective of the size the teeth. They are small Premaxillary max around 10 mm Maxillary max around 11 mm Dentary max around 8 mm The illustrations are based on real skulls NMMNH P-42200 a juvenile skull YPM 41196: considered a large adult skull Courtesy of: http://www.paleofile.com/Dinosaurs/Theropods/Coelophysis.asp 5 Link to comment Share on other sites More sharing options...
Troodon Posted August 26, 2018 Author Share Posted August 26, 2018 10 minutes ago, Bobby Rico said: This is a fantastic . Really helps us out . I am hoping to start a small Triassic collection . Thanks Frank Appreciate it what its for. Have fun putting it together. 1 Link to comment Share on other sites More sharing options...
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