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Hope everyone is having a nice weekend. I'm thinking this 6mm tooth (perhaps 7mm, if not for wear) from the Hell Creek formation of Garfield co, Montana is a Troodon premax. What do you think?
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"That some of these teeth are mammalian incisors there can be but little doubt..." - O. C. Marsh1 This kind of incisor-like ("incisiform") tooth was originally thought to have belonged to a large, Cretaceous mammal. Later discoveries revealed that these teeth were actually the front teeth ("premaxillary teeth") of Tyrannosaurs - and are now known as a hallmark of their clade, Tyrannosauroidea (along with fused nasals). Closely-spaced, parallel grooves on bones suggest that Tyrannosaurs used these teeth to selectively scrape meat from bone2. Identification Tyrannosaurid premaxillary teeth have a "D"-shaped cross section, with the lingual face flattened, and often have an apicobasal ridge on the midline of the lingual face. In more technical language, "...premaxillary teeth bear lingually rotated mesial and distal carinae forming a salinon cross-section at mid-crown height, and a highly convex labial aspect as in tyrannosauroids generally. In mesial/distal views carinae are sinuous, transitioning from lingually convex near the base to lingually concave approaching the occlusal surface. Carinae terminate prior to reaching the root/crown juncture. Mesial and distal aspects of the crown are depressed, yielding a weakly hourglass-shaped cross-section at the crown base... The carinae lack serrations [likely ontogenetically variable]... As in other tyrannosauroids, teeth exhibit a pronounced lingual ridge"3. Most of the current literature supports only one Tyrannosaurid species in the Hell Creek formation, Tyrannosaurus rex, a hypothesis subject to change in light of new evidence. Comments This tooth has no discernible antemortem wear. The collector appears to have applied some preservative coating, giving the enamel a slightly sharper gloss. Given the size, this is from a very young animal (smaller than "Jane", BMRP 2002.4.1). References 1. Marsh, O.C., 1892, "Notes on Mesozoic vertebrate fossils", American Journal of Science, 44: 170-176 2. David W.E. Hone and Mahito Watabe, "New information on scavenging and selective feeding behaviour of tyrannosaurs", Acta Palaeontologica Polonica 55 (4), 2010: 627-634 doi: http://dx.doi.org/10.4202/app.2009.0133 3. Zanno, L., Tucker, R.T., Canoville, A. et al. Diminutive fleet-footed tyrannosauroid narrows the 70-million-year gap in the North American fossil record. Commun Biol 2, 64 (2019). https://doi.org/10.1038/s42003-019-0308-7
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- hell creek
- hell creek formation
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"That some of these teeth are mammalian incisors there can be but little doubt..." - O. C. Marsh1 This kind of incisor-like ("incisiform") tooth was originally thought to have belonged to a large, Cretaceous mammal. Later discoveries revealed that these teeth were actually the front teeth ("premaxillary teeth") of Tyrannosaurs - and are now known as a hallmark of their clade, Tyrannosauroidea (along with fused nasals). Closely-spaced, parallel grooves on bones suggest that Tyrannosaurs used these teeth to selectively scrape meat from bone2. Identification Tyrannosaurid premaxillary teeth have a "D"-shaped cross section, with the lingual face flattened, and often have an apicobasal ridge on the midline of the lingual face. In more technical language, "...premaxillary teeth bear lingually rotated mesial and distal carinae forming a salinon cross-section at mid-crown height, and a highly convex labial aspect as in tyrannosauroids generally. In mesial/distal views carinae are sinuous, transitioning from lingually convex near the base to lingually concave approaching the occlusal surface. Carinae terminate prior to reaching the root/crown juncture. Mesial and distal aspects of the crown are depressed, yielding a weakly hourglass-shaped cross-section at the crown base... The carinae lack serrations [likely ontogenetically variable]... As in other tyrannosauroids, teeth exhibit a pronounced lingual ridge"3. Most of the current literature supports only one Tyrannosaurid species in the Hell Creek formation, Tyrannosaurus rex, a hypothesis subject to change in light of new evidence. Comments This tooth exhibits some antemortem wear at the apex (pictured), on the carinae, and near the base of the lingual apicobasal ridge. Given the size, this is from a juvenile animal (smaller than "Jane", BMRP 2002.4.1). References 1. Marsh, O.C., 1892, "Notes on Mesozoic vertebrate fossils", American Journal of Science, 44: 170-176 2. David W.E. Hone and Mahito Watabe, "New information on scavenging and selective feeding behaviour of tyrannosaurs", Acta Palaeontologica Polonica 55 (4), 2010: 627-634 doi: http://dx.doi.org/10.4202/app.2009.0133 3. Zanno, L., Tucker, R.T., Canoville, A. et al. Diminutive fleet-footed tyrannosauroid narrows the 70-million-year gap in the North American fossil record. Commun Biol 2, 64 (2019). https://doi.org/10.1038/s42003-019-0308-7
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From the album: Hell Creek / Lance Formations
This kind of incisor-like ("incisorform") tooth was originally thought to have belonged to a large, Cretaceous mammal. Later discoveries revealed that these teeth were actually the front teeth ("premaxillary teeth") of Tyrannosaurs - and are now known as a hallmark of their clade, Tyrannosauroidea. Closely-spaced, parallel grooves on bones suggest that Tyrannosaurs used these teeth to scrape meat from bone. Given the size, this is from a very young animal. Should Nanotyrannus be valid, then this should be considered an indeterminate Tyrannosaurid. -
From the album: Hell Creek / Lance Formations
This kind of incisor-like ("incisorform") tooth was originally thought to have belonged to a large, Cretaceous mammal. Later discoveries revealed that these teeth were actually the front teeth ("premaxillary teeth") of Tyrannosaurs - and are now known as a hallmark of their clade, Tyrannosauroidea. Closely-spaced, parallel grooves on bones suggest that Tyrannosaurs used these teeth to scrape meat from bone. Given the size, this is from a juvenile animal (smaller than "Jane"). Should Nanotyrannus be valid, then this should be considered an indeterminate Tyrannosaurid.-
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- aublysodon
- aublysodon mirandus
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From the album: Dinosaurs
These strange, incisor-like teeth were originally thought to have belonged to a large Cretaceous mammal. Later discoveries showed that these teeth matched the front teeth of young Tyrannosaurs quite well. Given closely spaced, parallel feeding traces on bones, these "incisorform" teeth likely were used to scrape meat from bone. -
Hey all, Do you think it's safe to say that this fella went mouth-to-mouth with a contemporary (antemortem) and got the other's serrations stamped on the tip of his front tooth? In this first pic, it almost looks like the tooth got raked against another's serrations, starting or ending with the point of significant imprint.
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Hi all, Saw this tooth and Im not really sure how to distinguish pachy and thesc premax teeth well. Looked at @Troodon’s thread though from what I can see, I think Im leaning towards my tooth as a pachy just based on morphology similarities. Tooth is from Powder River County, Montana and is 5/16th of an inch. Thanks!
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Hello all! I have acquired a very nice juvenile tyrannosaurid tooth from the Judith River Formation. I am fully aware that teeth from there are very difficult to be assigned a specie, but I was wondering if it could be narrowed down a little. Last time @Troodon was able to give me awesome info and help. The tooth is a premax tooth and is 1,7cm in length. I have a serration count for both distal and mesial sides: hard to tell for sure but it looks like 3/mm for the distal 4/mm for the mesial Thank you very much for all imput and info Kind regards, Thomas
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I've just received this weird little tooth from the Hell Creek Formation. It was sold to me as a Dromaeosaur premax tooth but I have my doubts as it's quite robust. That said, the other candidate would be a Tyrannosaur and I've never seen a premax tooth with a twist like this. What's more, the carinae are strange - one has nice crisp serrations (I thought they looked a lot like Tyrannosaur serrations) while the other is smooth (it doesn't look like it ever had any serrations). Anyone have any idea what it might be?
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A premaxillary tooth of an Abelisaurid.
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- abelisaur
- cenomanian
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More real or fake shenanigans
BonuFrailman posted a topic in Is It Real? How to Recognize Fossil Fabrications
Hey guys, I know I’ve been overzealous with the real or fake posts but I have had this link bookmarked for a while and wanted to know if this is indeed a Premax trex tooth. All of the website’s fossils are from the Hell creek formation, this included.
