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Showing results for tags 'dentition'.
Found 25 results
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Frenchetal.17-toothontogeneticmorphologyinwhitesharks.pdf Journal of Fish Biology (2017) 91, 1032–1047 The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias G. C. A. French, M. Stürup, S. Rizzuto, J. H. Van Wyk,D. Edwards, R. W. Dolan, S. P. Wintner A. V. Towner and W. O. H. Hughes BTW:that's a horrible pun to inflict on humanity From the text: "One of the major limitations in establishing the ontogenetic relationships between morphology, diet and maturity, especially in threatened species, is sample size." And that's in the Recent,folks. Is sample size in fossils my hang up,then? Because I keep harping on about it? (my shrink keeps gesturing..
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Associated Cretoxyrhina (vraconensis) dentition
britishcanuk posted a topic in General Fossil Discussion
Hi, Recently, I had the good fortune to acquire this set of Cretoxyrhina (vraconensis) teeth from the Britton Fm., Texas. I have a detailed account of it’s discovery which describes almost all of these teeth being found together in an area about 18” x18”, with a few stragglers found just outside the main pile of teeth. It’s not complete, but It looks like most of the positions are represented. Some of the larger anteriors were not recovered and I suspect at least one or two positions are missing. I have arranged these teeth into positions that look close to me, but there is no doubt that it needs to be adjusted. I am hoping someone here might know something about these early Cretoxyrhina dentitions and might be able to advise or comment on how I can make this accurate. Some other noteworthy finds recovered from the same 18” square were 2 suspected Cretoxyrhina vertebrae, 5 small Squalicorax (falcatus) teeth, a possible Archeolamna tooth, another very small unidentified cusped shark tooth, and some small fish vertebrae and bones. Thanks for looking. R~- 5 replies
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- dentition
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Early Cretoxyrhina (vraconensis) dentition question
britishcanuk posted a topic in General Fossil Discussion
I’m wondering if anyone has put together a dentition of an early Cretoxyrhina with narrow lower teeth and cusped laterals and posteriors. If you have photos of something like this I would very much appreciate seeing what one looks like. Thanks in advance! R~ -
A new large Late Cretaceous lamniform shark from North America, with comments on the taxonomy, paleoecology, and evolution of the genus Cretodus Kenshu Shimada &Michael J. Everhart Article: e1673399 | Received 30 Nov 2018, Accepted 09 Sep 2019, Published online: 18 Nov 2019 LINK (description of Cretodus houghtonorum n.sp) edit:5,30 MB,or thereabouts relevant: Philosophical Transactions of the Royal Society of London. Series B, Containing Papers of a Biological Character Vol. 210 (1921), pp. 311-407 V I I I .— On the Calcification o f the Vertebral Centra in Sharks and Rays. B y W . G. R id e w o o d, D.Sc. 18 MB!!
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- axial skeleton
- von bertalanffy growth function
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ray Dental sexual dimorphism and morphology of Urotrygon microphthalmum Bianca de Sousa Rangel Zoomorphology,april 2016 RECOMMENDED
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Development and Evolution of Dentition Pattern and Tooth Order in the Skates And Rays (Batoidea; Chondrichthyes) Charlie J. Underwood,*, Zerina Johanson,, Monique Welten,, Brian Metscher,Liam J. Rasch,, Gareth J. Fraser,, Moya Meredith Smith Citation: Underwood CJ, Johanson Z, Welten M, Metscher B, Rasch LJ, Fraser GJ, et al. (2015) Development and Evolution of Dentition Pattern and Tooth Order in the Skates And Rays (Batoidea; Chondrichthyes). PLoS ONE 10(4): e0122553. https://doi.org/10.1371/journal.pone.0122553 given the collective NOUS and expertise of the authors:DO NOT MISS THIS ONE!!!
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- ichthyology
- elasmobranch
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Quite some years back my late uncle purchased the attached fossil at a gem show here locally. Too be completely honest it looks kind of fake to me... but im might just have a untrained eye. My Aunt has taken the picture. I Couldn't possibly imagine it being from around here so I'm really not sure what age it could be or what location it is from. I'll try to acquire some more photos with a scale shortly. I know its a shot in the dark but any feedback would be greatly appreciated. -Nick
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Hi guys! I just uploaded a gallery of modern Carcharhinus upper dentitions: . The images are from my master's thesis (Smith 2015), the full text is available at (https://www.researchgate.net/publication/316735477_Species_discrimination_in_Carcharhinus_shark_teeth_using_elliptic_Fourier_analysis). Unfortunately, due to file size limitations, the images in the paper are not really good enough for detailed analysis of the morphology. So I have uploaded them individually here. I personally extracted the teeth from almost all of these jaws...If I remember correctly, they were soaked in isopropyl alcohol for several days and then the teeth removed with toothpicks and/or just pulling them out with my fingers. I cut up my fingers too many times to count trying to get these suckers out! Only the upper dentition is included; the bottom teeth in Carcharhinus are very same-y so we just focused on the uppers. Keep in mind, these represent only twelve species out of over thirty described species. They are biased towards species today present in the Western Atlantic/Gulf of Mexico. Five species now present in the Western Atlantic/Gulf of Mexico were not included due to lack of specimens/time: C. altimus, C. galapagensis, C. perezi, C. porosus, and C. signatus. Other Carcharhinus dentitions are available on the net. J-elasmo has some, I believe mostly collected from near Japan: http://naka.na.coocan.jp/JAWCarcharhinidae.html. They generally match well with my dentitions, although their Silky (C. falciformis) dentition is more coarsely serrated at the tips than mine, and the lateral notch, which is prominent in my specimens, is basically absent in the J-elasmo dentition. And of course there is Elasmo.com, a great resource for all sharks, not just Carcharhinus. Their C. falciformis dentition is similar to mine, so I don't know what's going on with J-elasmo's dentition, either it's mislabeled or Silky teeth look a lot different in the western Pacific. Or it's just an unusual specimen. And of course there are a bunch of papers online with Carcharhinus teeth, although these are generally isolated fossil teeth. The single best resource I could find for Carcharhinus identication based on teeth is unfortunately difficult to obtain, and would probably require an interlibrary loan request: Garrick, J. A. F. (1982). Sharks of the genus Carcharhinus. US Dep. Commer. NOAA Tech. Rep. NMFS Circular, 445, 194. His shark teeth images are illustrations, but well done, and with a lot of descriptive information. Purdy et al. (2001) is also a good reference:(https://www.researchgate.net/publication/284595551_The_Neogene_sharks_rays_and_bony_fishes_from_Lee_Creek_Mine_Aurora_North_Carolina). You can find references to several papers related to fossil Carcharhinus, as well as a general overview of their fossil record, in my thesis. Finally, I'm attaching a figure from my thesis, illustrating the morphological terminology used: C. falciformis, upper right jaw, 5th position from symphysis. Feel free to add additional references or information about the genus Carcharhinus. Or if anything is incorrect in this post. The subject of fossil Carcharhinus tooth identification comes up fairly regularly in the forums, so let's try and stick as much information in here as possible!
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Found at Myrtle Beach South Carolina, thought it might be some kind of ray tooth plating but it doesn't match any of the ray stuff I have, any ideas? One picture has the ray teeth I'm familiar with to the left of unknown piece.
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Recommended!
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- signaling cascade
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xinxuxiaolsmallestdinosazhaoianusmicrorapnaturezhonghetopost200010b4c14c3.pdf the other paper on this species(Hwang/Norell) is ,naturally,in Fruitbat's Library,possibly in some others as well salient points(or:"things you might want to remember about this article")(apart from osteological details): edit,hours later:possible repost,because I just noticed this one in Fruitbat's Library. Joe,i feel i owe you an apology. note Maniraptora (GAUTHIER): I posted the Gauthier,a very influential cladistic paper,a while back Note 2: "Archaeoraptor" turned out to be forged
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- cretaceous
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Intermediate and Symphyseal/Parasymphyseal teeth in sharks
The Jersey Devil posted a topic in General Fossil Discussion
Hey everyone, I was just wondering what exactly intermediate teeth were and also what the difference between symphyseal and parasymphyseal teeth is. The small fourth tooth in the upper jaw of Carcharias taurus is marked as an intermediate. Thanks for any help!- 3 replies
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- symphyseal teeth
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sizetheropusapalaiosOntootroodontologgigant_the_Occurrence_of_Exceptionally_Large.pdf
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- alaska
- dinosauria
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deklnqwebl_2012.pdf Outtake:
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euheloptitanosaudentittheFULLTEXT01_(1).pdf outtake:
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EHRET_al-2012-Palaeontology.pdf
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- elasmobranch
- pisces
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toot
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- morphogenesis
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My attempt at a one row megalodon and great white jaw
mattbsharks posted a topic in General Fossil Discussion
This is my attempt at arranging the teeth. I thought it would be fun to try. I have no idea how to construct the actual jaw or how to do proper dentition. Dog provided for reference. The photos were too large to post so here are the links: https://drive.google.com/file/d/0B7QcbeYzTMs6MnBNbnlfcTJPcFk/view?usp=sharing https://drive.google.com/file/d/0B7QcbeYzTMs6cFVDbVBaclBaanM/view?usp=sharing https://drive.google.com/file/d/0B7QcbeYzTMs6VVNWdkVBNGVpMzQ/view?usp=sharing https://drive.google.com/file/d/0B7QcbeYzTMs6NnJTMldiT08wbEk/view?usp=sharing https://drive.google.com/file/d/0B7QcbeYzTMs6Q3h2cGhwTVN2VFk/view?usp=sharing https://drive.google.com/file/d/0B7QcbeYzTMs6QWhPc2ROX1JRT1U/view?usp=sharing -
Wondering if this megalodon tooth could have come from a world class megalodon shark
mattbsharks posted a topic in Questions & Answers
I recently acquired this megalodon tooth. It would have measured about 5.9 inches on the slant if the tip was intact, and measures 5.1 inches across. This question is for all you shark tooth dentition experts out there. I have never come across a megalodon tooth this big that appears to be a posterior which leads me to my first question, is it possible that this tooth came from a world class size megalodon with 7 inch teeth? I was also wondering what differentiates a megalodon from a chubutensis. I know that chubs have cusps, but it seems rather ambiguous to me with some megs appearing to have cusps or dips at the end of the blades. Thanks, Matt -
famo_miohiporgon.pdf fairly new,as these things go. Size:< 1 Mb "Statistical methods will better inform analyses that address the continent-wide issue of distinguishing Mesohippus from Miohippus. These two genera are difficult to distinguish(Stirton, 1940), but are considered distinct based on the presence and condition of the articular facet on the third metatarsal, which articulates with the cuboid; larger hypostyles; a longer face(*); and a deeper facial fossa (Prothero and Shubin, 1989; MacFadden,1998). The paleopopulation of John Day Miohippus is not adequate in addressing this issue because there are only five occurrences of Mesohippus in the entire assemblage. Very few specimens from the Turtle Cove assemblage were identified as Mesohippus, and those that were identified as such were determined to be statistically different from the specimens of Miohippus. " (*): for the ones among us who see the funny side of equid systematics
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After this horrendous attempt at a triple pun,things can only deteriorate,right? The list of species in the tags i have kept to a bare bones minimum,for clarity's sake i MIGHT not have posted this,but it figures tooth rows. Shark cognoscendi prolly already have this one(and the others by Bass)I'm sure. SO,no need to post those others orrep38a.pdf
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edit: mind you,this one is fairly recent streetcaldhoffmannii_squammosrevisi!us.pdf
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caldwlcraniumosasaurdentitij.1.x.pdf Terrific paper from ZJLS,ignore at your own peril
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I hope some of you may like this
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- jurassic
- macronaria
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