Emthegem Posted May 31, 2020 Share Posted May 31, 2020 Hello! It was found in the Georgian Bay Formation - Ordovician period, in West Toronto. It was found after cracking some rocks on the riverbanks of Etobicoke creek. I recently came across a rather peculiar fossil, I initially though it might have been an ammonite, but those didn't exist until much later than the Ordovician period. It seems to be slightly ribbed, with a bit of a spine. - Link to comment Share on other sites More sharing options...
Emthegem Posted May 31, 2020 Author Share Posted May 31, 2020 - Link to comment Share on other sites More sharing options...
Emthegem Posted May 31, 2020 Author Share Posted May 31, 2020 - Link to comment Share on other sites More sharing options...
FossilDAWG Posted May 31, 2020 Share Posted May 31, 2020 I'm pretty sure this is a tergomyid, Cyrtolites. See here for a photo. These loosely coiled shells with a sharp keel used to classified as snails, but some time ago they were recognized as monoplacophorans (now named the class Tergomya) based on the position of internal muscles, which can be recognized by the attachment scars they left on the inside of the shell. Other "snails" in the group include common planispiraly coiled genera including Sinuites which is more common than Cyrtolites in the Georgian Bay Formation. Don 6 Link to comment Share on other sites More sharing options...
Emthegem Posted May 31, 2020 Author Share Posted May 31, 2020 44 minutes ago, FossilDAWG said: I'm pretty sure this is a tergomyid, Cyrtolites. See here for a photo. These loosely coiled shells with a sharp keel used to classified as snails, but some time ago they were recognized as monoplacophorans based on the position of internal muscles, which can be recognized by the attachment scars they left on the inside of the shell. The name for the taxonomic Family is the Tergomyidae. Other "snails" in the group include common planispiraly coiled genera including Sinuites which is more common than Cyrtolites in the Georgian Bay Formation. Don Wow thats awesome! this is finally a new fossil for my collection, thanks for the ID! - Link to comment Share on other sites More sharing options...
Wrangellian Posted May 31, 2020 Share Posted May 31, 2020 Interesting! There's always something new. 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted May 31, 2020 Share Posted May 31, 2020 2 hours ago, FossilDAWG said: I'm pretty sure this is a tergomyid, Cyrtolites. See here for a photo. These loosely coiled shells with a sharp keel used to classified as snails, but some time ago they were recognized as monoplacophorans based on the position of internal muscles, which can be recognized by the attachment scars they left on the inside of the shell. The name for the taxonomic Family is the Tergomyidae. Other "snails" in the group include common planispiraly coiled genera including Sinuites which is more common than Cyrtolites in the Georgian Bay Formation. Don I've not heard of this family? I know that the class that used to be Monoplacophora is now Tergomya, but I thought the family for Cyrtolites is Cyrtolitidae? I'm not sure about Sinuites, it keeps moving between Gastropoda and Tergomya. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 1, 2020 Share Posted June 1, 2020 You're correct, I got confused about the level Tergomya applied to. Thanks for the correction. Don Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted June 1, 2020 Share Posted June 1, 2020 3 hours ago, FossilDAWG said: You're correct, I got confused about the level Tergomya applied to. Thanks for the correction. Don Tis easily done. I'm trying to update my classification of bivalves at the moment and it's making me very confused indeed. 1 Life's Good! Tortoise Friend. 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