Dino Dad 81 Posted January 13 Share Posted January 13 Hi all, This eggshell fragment is from the Two Medicine formation in Browning, Montana. I'm trying to figure out if it's smooth enough to fall into the Troodon camp or if it's a worn down specimen that previously had ornamentation. I'm leaning towards Troodon eggshell with calcite coating. Thanks!! Link to post Share on other sites
Rockwood Posted January 13 Share Posted January 13 @Troodon Who else ? Link to post Share on other sites
Dino Dad 81 Posted January 13 Author Share Posted January 13 @jpc too Link to post Share on other sites
caterpillar Posted January 13 Share Posted January 13 Are you sure it's an eggshell? I don't see the classic radiate structure on the edge 1 Link to post Share on other sites
Troodon Posted January 13 Share Posted January 13 It's a Two Medicine unidentified eggshell, not Troodon, like you said those are smooth. More like "c" in the illustration 1 Link to post Share on other sites
jpc Posted January 13 Share Posted January 13 I have to go with caterpillar... the cross section does not show the crystals going perpendicular to the surface. Rather the structure in there is going parallel to the surface (see your third photo). I think tis is a calcite deposit or something like that. Not an egg piece. Sorry. 1 1 Link to post Share on other sites
Troodon Posted January 13 Share Posted January 13 Here is a TMF Hadrosaur egg. The pores are call Prolatocanaliculate. Eggs and eggshell fragments from the Upper Cretaceous Two Medicine Formation of Montana Karl F. Hirsch & Betty Quinn 2010 Link to post Share on other sites
jpc Posted January 13 Share Posted January 13 Hmmmm...... thanks for this, troodon. Maybe it is an eggshell. 1 Link to post Share on other sites
Randyw Posted January 13 Share Posted January 13 I’m with troodon onthis one. Looks like an egg shell fragment but from what i couldn’t say. 1 Link to post Share on other sites
JohnJ Posted January 13 Share Posted January 13 I think better focused images of the edges would be informative. 1 Link to post Share on other sites
Dino Dad 81 Posted January 13 Author Share Posted January 13 Here are some additional shots: I'm surprised Troodon isn't a possibility. It seems from all the pictures I'm looking at that very little of Troodon egg surface actually shows the underlying smoothness, since most is covered in calcite or other minerals. In the pic with the very smooth section, they say the smooth section only covers the bottom 1/3. And is it possible for ornamentation to get so uniformly eroded, yet the sides and underneath surface be so well-preserved? Here are some closer up pics from the Troodon eggs in my original post: Embryos_and_eggs_for_the_Cretaceous_theropod_dinos.pdf Link to post Share on other sites
Dino Dad 81 Posted January 13 Author Share Posted January 13 Also, here's a close up of the edge. The grain is parallel to the surface rather than perpendicular: Most of what I'm looking at comes from this: Embryos_and_eggs_for_the_Cretaceous_theropod_dinos.pdf Link to post Share on other sites
Rockwood Posted January 13 Share Posted January 13 My two cents, this looks like the texture of shell to me. 1 Link to post Share on other sites
jpc Posted January 13 Share Posted January 13 I'm convinced... dino egg. 1 Link to post Share on other sites
Dino Dad 81 Posted January 13 Author Share Posted January 13 On my way down to see the new responses, I past the Hadrosaur cross-section and was reminded how incredibly deep the Prolatocanaliculate go. I'll be curious to see if you still think it's unidentifiable. Not challenging anything--just curious to know if this is incremental information and, if so, whether it matters. Troodon Hadrosaur Troodon Link to post Share on other sites
Randyw Posted January 13 Share Posted January 13 I’m still in the unidentified camp. The remains of the bumps on the shell matches troodons example c. They arent ridges like example b and too rough to be troodon…. 1 Link to post Share on other sites
Dino Dad 81 Posted January 14 Author Share Posted January 14 Right.. I shouldn't be looking at as necessarily being one or the other. Troodon's main point was only that the grain can run parallel. Link to post Share on other sites
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