FossilsandScience Posted August 3, 2020 Share Posted August 3, 2020 Hey everyone! I have a quick question on baby tyrannosaur teeth and their rarity compared to adult or subadult tyrannosaur teeth. Which is rarer to find? I would assume baby tyrannosaur teeth would be rarer, but at the same time, most tyrannosaurs didn’t even make it to adulthood. So which would you say? Are baby tyrannosaur teeth or adult tyrannosaur teeth rarer? Any answer is appreciated! Thanks everyone! Link to comment Share on other sites More sharing options...
Troodon Posted August 3, 2020 Share Posted August 3, 2020 My experience clearly points to teeth around 5 to 10 mm are the rarest. Harder to find because of size and most collectors don't recognize them as tyrannosaurid. Teeth 1.5 inch or less are what you typically see but I find it difficult to determine if they are unerupted from a subadult/adult or functional juvie. 6 Link to comment Share on other sites More sharing options...
Praefectus Posted August 3, 2020 Share Posted August 3, 2020 @Troodon How do you differentiate juvenile rex teeth from adult ones? Link to comment Share on other sites More sharing options...
Troodon Posted August 3, 2020 Share Posted August 3, 2020 32 minutes ago, Praefectus said: @Troodon How do you differentiate juvenile rex teeth from adult ones? No idea on isolated teeth juvie sized teeth could simply be unerupted teeth from adults. Presence of wear facets can identify functional teeth. Here is a baby Trex dentary with some nice size teeth 5 Link to comment Share on other sites More sharing options...
Praefectus Posted August 4, 2020 Share Posted August 4, 2020 Very interesting. I've seen a lot of isolated rex teeth that were labeled "juvie." Thanks for the information. Link to comment Share on other sites More sharing options...
PaleoNoel Posted August 4, 2020 Share Posted August 4, 2020 That's the one Dr. Steve Nicklas found w/PaleoProspectors. I'm surprised it doesn't get talked about more in the Nano debate. 1 Link to comment Share on other sites More sharing options...
hadrosauridae Posted August 4, 2020 Share Posted August 4, 2020 12 hours ago, Praefectus said: Very interesting. I've seen a lot of isolated rex teeth that were labeled "juvie." Thanks for the information. Thats because sellers who dont believe that "nano" is its own species label all small tyranosaurid teeth as juvenile. "There is no shortage of fossils. There is only a shortage of paleontologists to study them." - Larry Martin Link to comment Share on other sites More sharing options...
Troodon Posted August 4, 2020 Share Posted August 4, 2020 10 hours ago, PaleoNoel said: That's the one Dr. Steve Nicklas found w/PaleoProspectors. I'm surprised it doesn't get talked about more in the Nano debate. Well Pete Larsen has consistently used that jaw to compare against Nanotyrannus ones. The problem being its privately owned and the primary advocate against two species refuses to consider anything that is not in the holy sanctum of a museum 4 Link to comment Share on other sites More sharing options...
Praefectus Posted August 4, 2020 Share Posted August 4, 2020 39 minutes ago, hadrosauridae said: Thats because sellers who dont believe that "nano" is its own species label all small tyranosaurid teeth as juvenile. I was talking more about when sellers haphazardly label anything small as juvenile. I agree, there are a lot of mis-labeled nano teeth out there too. Link to comment Share on other sites More sharing options...
Troodon Posted August 4, 2020 Share Posted August 4, 2020 What I've seen is lots of very small tyrannosaurid teeth labeled as Dromaeosaurid or Dromaeosaur just out of ignorance. Lots of sellers are just clueless and just base identification based on size. 2 Link to comment Share on other sites More sharing options...
FossilsandScience Posted August 4, 2020 Author Share Posted August 4, 2020 3 hours ago, Troodon said: What I've seen is lots of very small tyrannosaurid teeth labeled ad Dromaeosaurid or Dromaeosaur just out of ignorance. Lots of sellers are just clueless and just base identification based on size. I’ve seen this very often as well. One seller listed a tooth as a Dromeosaurid and I bought it because it looked tyrannosaur to me. Ended up being a hatchling T. Rex tooth (the tooth was about 9-10mm)! Looking very closely at teeth labeled Dromeosaurid can pay off! 1 Link to comment Share on other sites More sharing options...
Troodon Posted August 4, 2020 Share Posted August 4, 2020 45 minutes ago, FossilsandScience said: I’ve seen this very often as well. One seller listed a tooth as a Dromeosaurid and I bought it because it looked tyrannosaur to me. Ended up being a hatchling T. Rex tooth (the tooth was about 9-10mm)! Looking very closely at teeth labeled Dromeosaurid can pay off! Good point, Ive picked up some very nice material that was misidentified so it always pays try to identify it yourself and not rely on the sellers call. Link to comment Share on other sites More sharing options...
Dracarys Posted August 4, 2020 Share Posted August 4, 2020 Here’s my baby Rex tooth. One can see how robust it is even though it’s tiny. 8 Link to comment Share on other sites More sharing options...
Jaimin013 Posted August 5, 2020 Share Posted August 5, 2020 Hi All, I thought that I would make a contribution to this topic by posting a pic of my rooted juvenile tyrannosaurus rex tooth (first pic). I've only seen a few teeth like it. It was advertised as a dromaeosaurid tooth but having spoken to multiple people (including Pete Larson, Bucky Derflinger) they all lean towards it likely being a juvenile tyrannosaurus tooth because of how robust/banana shaped it is. The tooth looks different than most of the teeth that Troodon has posted in the jaw of baby Trex dentary (with the exception of perhaps the last tooth closest to the front of the jaw in the middle jaw pic) but as the root of the teeth are not exposed in the jaw it's difficult to make a comparison. Would be cool if a scan could be done on it someday which allows us to determine how the roots of the teeth look like. The shape of a tooth is likely to depend on tooth position so maybe that's why it doesnt match most of the teeth in that jaw. @Dracarys I also have a tooth that is similar to yours (see third pic). Like Troodon says juvie sized teeth could simply be unerupted teeth from adults rather than a functional juvie so not sure how to tell. Although the tooth in the third pic is robust like trex teeth, it's hard to tell if the tooth in the third pic would be arguably different from the first tooth if it was rooted. The life cycles/stages and terminology are all too confusing for me (baby, juvenile, adult... and how do you class something as a sub-adult... is it at the juvenile stage, is it past the juvenile stage and anywhere between juvenile and adult, when do you stop calling something a baby rather than juvenile (as juvenile just means young so I assume baby falls into that category) and are there slight differences in the way the teeth look depending on this on top of the differences in tooth shape depending on the location in the jaw. Perhaps the third tooth may look similar to the first tooth if it was rooted rather than shed i dont know. As you can see in the fourth pic comparing all of my nano/rex teeth side by side it's not impossible. I've seen a few other pics of juvenile rex teeth including from individuals such as baby bob (see last pics of Baby Bob's teeth) which look different than the tooth in my first pic which may be due to tooth position or perhaps maybe teeth like the ones myself and @Dracarys have posted are more closer to baby than juvenile or sub-adult. This goes back to how difficult it is to make a call with isolated teeth and not being able to see the bigger picture with rest of the teeth in a jaw. Regarding rex vs nano, the second pic is a rooted Nanotyrannus tooth found by PaleoAdventures (if anyone is interested). Obviously, you can see that rex teeth are different than nano. Just look at how robust rex teeth are compared with Nano. It also helps when you can compare fully rooted teeth. Anyway I am probably going off topic/ranting but going back to the original question by @FossilsandScience I would say yes baby teeth are rarer. I just don't see them as often. It's also very difficult to call with small teeth whether it's nano rather than rex especially when you sometimes find "in-between teeth" which are hard to differentiate like the one in the fourth pic, fourth tooth. Baby Bob teeth 3 Link to comment Share on other sites More sharing options...
Dracarys Posted August 5, 2020 Share Posted August 5, 2020 3 hours ago, Jaimin013 said: Hi All, I thought that I would make a contribution to this topic by posting a pic of my rooted juvenile tyrannosaurus rex tooth (first pic). I've only seen a few teeth like it. It was advertised as a dromaeosaurid tooth but having spoken to multiple people (including Pete Larson, Bucky Derflinger) they all lean towards it likely being a juvenile tyrannosaurus tooth because of how robust/banana shaped it is. The tooth looks different than most of the teeth that Troodon has posted in the jaw of baby Trex dentary (with the exception of perhaps the last tooth closest to the front of the jaw in the middle jaw pic) but as the root of the teeth are not exposed in the jaw it's difficult to make a comparison. Would be cool if a scan could be done someday on it which allowed us to determine how the roots of the teeth look like. The shape of a tooth is likely to depend on tooth position so maybe that's why it doesnt match most of the teeth in that jaw. @Dracarys I also have a tooth that is similar to yours (see third pic). Like Troodon says juvie sized teeth could simply be unerupted teeth from adults rather than a functional juvie so not sure how to tell. Although the tooth in the third pic is robust like trex teeth, it's hard to tell if the tooth in the third pic would be arguably different from the first tooth if it was rooted. The life cycles/stages and terminology are all too confusing for me (baby, juvenile, adult... and how do you class something as a sub-adult... is it at the juvenile stage, is it past the juvenile stage and anywhere between juvenile and adult, when do you stop calling something a baby rather than juvenile (as juvenile just means young so I assume baby falls into that category) and are there slight differences in the way the teeth look depending on this on top of the differences in tooth shape depending on the location in the jaw. Perhaps the third tooth may look similar to the first tooth if it was rooted rather than shed i dont know. As you can see in the fourth pic comparing all of my nano/rex teeth side by side it's not impossible. I've seen a few other pics of juvenile rex teeth including from individuals such as baby bob (see last pics of Baby Bob's teeth) which look different than the tooth in my first pic which may be due to tooth position or perhaps maybe teeth like the ones myself and @Dracarys have posted are more closer to baby than juvenile or sub-adult. This goes back to how difficult it is to make a call with isolated teeth and not being able to see the bigger picture with rest of the teeth in a jaw. Regarding rex vs nano, the second pic is a rooted Nanotyrannus tooth found by PaleoAdventures (if anyone is interested). Obviously, you can see that rex teeth are different than nano. Just look at how robust rex teeth are compared with Nano. It also helps when you can compare fully rooted teeth. Anyway I am probably going off topic/ranting but going back to the original question by @FossilsandScience I would say yes baby teeth are rarer. I just don't see them as often. It's also very difficult to call with small teeth whether it's nano rather than rex especially when you sometimes find "in-between teeth" which are hard to differentiate like the one in the fourth pic, fourth tooth. Baby Bob teeth Nice pictures and comparisons. My tooth has fair amount of tip wear --> he was definitely using it. 1 Link to comment Share on other sites More sharing options...
hadrosauridae Posted August 5, 2020 Share Posted August 5, 2020 Great photos. This is the only baby-Rex tooth I've found. 2 "There is no shortage of fossils. There is only a shortage of paleontologists to study them." - Larry Martin Link to comment Share on other sites More sharing options...
jdp Posted August 5, 2020 Share Posted August 5, 2020 On 8/3/2020 at 5:58 PM, Troodon said: No idea on isolated teeth juvie sized teeth could simply be unerupted teeth from adults. Presence of wear facets can identify functional teeth. Here is a baby Trex dentary with some nice size teeth A 35 cm dentary is still quite a bit larger than a neonate. I'm aware of one possible neonatal or embryonic jaw, which may be published at some point soon. We'll see. 1 Link to comment Share on other sites More sharing options...
FossilsandScience Posted August 6, 2020 Author Share Posted August 6, 2020 This is my baby Rex tooth here! You can tell it isn’t an unerupted tooth because it has some feeding wear. 2 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now