Monica Posted April 23, 2017 Share Posted April 23, 2017 Hello once again! Yesterday when I went out with Viola to Mimico Creek in Toronto (Georgian Bay Formation, Upper Ordovician), I found an interesting piece and I'd like your thoughts regarding its identity. The dome-shaped object in the photos below has bumps all over it, and there are tiny pores throughout, so I was wondering if you think it's a bryozoan or perhaps a stromatoporid (apparently Labechia huronensis is a bumpy-looking stromatoporid that can be found in the Georgian Bay Formation, but MANY bryozoans can be found here, too - including on this piece of rock! - so I'm not sure which it is). "Front" of specimen: "Back" of specimen: What is the conical-shaped, segmented item in the upper right-hand corner, by the way? Closer views of the bumpy, dome-shaped object: Thanks for your help! Monica 2 Link to comment Share on other sites More sharing options...
Archimedes Posted April 23, 2017 Share Posted April 23, 2017 Hi looks like some nice Bryozoans and on the back side is a nice Tentaculites 3 Link to comment Share on other sites More sharing options...
Rockwood Posted April 23, 2017 Share Posted April 23, 2017 Pretty sure that's a tabulate coral. Agreed on the Tentaculites. 1 Link to comment Share on other sites More sharing options...
piranha Posted April 23, 2017 Share Posted April 23, 2017 1 hour ago, Monica said: ...bumpy, dome-shaped object... Compare with the trepostome bryozoan: Stigmatella figure from: Hessin, W.A. (2009) South-Central Ontario Fossils: A Guide to the Ancient Marine Life of the Region. Cobourg, Ontario, Canada, 286 pp. 2 Link to comment Share on other sites More sharing options...
Rockwood Posted April 23, 2017 Share Posted April 23, 2017 Bumpy ? Guess I don't see the same. Oh. On a slightly larger scale. Could be. 1 Link to comment Share on other sites More sharing options...
fifbrindacier Posted April 23, 2017 Share Posted April 23, 2017 I agree with Piranha. Nice find. 1 "On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry) "We only well see with the heart, the essential is invisible for the eyes." In memory of Doren Link to comment Share on other sites More sharing options...
abyssunder Posted April 23, 2017 Share Posted April 23, 2017 I'm thinking about an assemblage of Cornulites, bryozoan encrusting a stromatoporoid. 1 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 KEY 1 Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 4 hours ago, Archimedes said: Hi looks like some nice Bryozoans and on the back side is a nice Tentaculites 4 hours ago, Rockwood said: Agreed on the Tentaculites. Hi there! Tentaculites sp. is pretty exciting for me since I've never found one before! In fact, I only just heard of their existence about a month ago when I was in contact with a fossil-hunter out in the London, Ontario area!!! The book that I've been using to try to get some idea of what I've been finding in my area doesn't include any discussion about Tentaculites sp. so I didn't even think that it would be a possibility, but now that you've mentioned it, that little guy (circled in yellow) does indeed look like one! Thanks for chiming in! Monica Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 tentaculites are important in Devonian biostratigraphy!!! Some bioevents are named after them 1 Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 3 hours ago, piranha said: Compare with the trepostome bryozoan: Stigmatella figure from: Hessin, W.A. (2009) South-Central Ontario Fossils: A Guide to the Ancient Marine Life of the Region. Cobourg, Ontario, Canada, 286 pp. Hi! That does look like a decent match to my specimen, and since Stigmatella sp. is indeed found in the Georgian Bay Formation, then that is probably what I have. Thanks for helping me out! Monica PS - I actually have a hard copy of the book you cited, but there are so many bryozoans listed that it's all a bit of a blur to me. I was also secretly hoping that I had found a stromatoporid since I've not yet found one, but it's time for me to face the facts - I believe that what I found is indeed a nice-looking little bryozoan Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 Use PDFs:they are searchable I've just downloaded Ulrich & Bassler to take a peek at Stigmatella. Confusingly enough,Stigmatella also seems to be something else "Zoarium variable, ranging from incrusting to irregularly massive and ramose. Zocecia angular, rounded, or irregularly petaloid, the shape depending upon the presence (or absence ) of mesopores and the number of acanthopores. Typically the zoarial surface exhibits at regular intervals maculae or spots composed of mesopores, although in some species the usual monticules or clusters of large cells occur. Acanthopores always present but variable in number, intermittent, developed chiefly in narrow zones, sometimes inconspicuous but more often so numerous as to give the surface a decidedly hirsute appearance. Mesopores, when present, developed in mature region only, their number being variable even for the same species. The zocecial tubes have thin walls in the axial region and these become but slightly thickened in the peripheral region wdiere a few unusually delicate diaphragms are inserted. In vertical sections the walls exhibit at rather regular intervals in the peripheral region thickening's somewhat similar to those occurring in Stenopora. These thickenings occur approximately at the same height in the walls, and tangential sections through these zones give the full development of acanthopores. Minute structure of walls as shown in tangential sections, of the type that characterizes the Heterotrypida. Genotype.—Stigmatella crenulata new species. Richmond formation 1 Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 1 hour ago, abyssunder said: I'm thinking about an assemblage of Cornulites, bryozoan encrusting a stromatoporoid. Hi abyssunder! I would LOVE to have found something other than a bryozoan, but I think piranha found a match to my specimen, and I believe that it is indeed the bryozoan Stigmatella sp. I was just wondering about your suggestion regarding Cornulites sp. - do you think that's what I have in the upper right-hand corner of the "back" side of the rock? If so, how can I tell between that and Tentaculites sp.? Or should I just label it as "Class Tentaculita" since both genera belong to that class? Also, do you see any other candidates on my rock that can also be given this label? Thanks so much! Monica Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 4 minutes ago, doushantuo said: Use PDFs:they are searchable I've just downloaded Ulrich & Bassler to take a peek at Stigmatella. Confusingly enough,Stigmatella also seems to be something else Hi doushantuo! If it's any help, the names given in my book are as follows: Stigmatella personata lobata Dyer Stigmatella vulgaris Parks and Dyer Monica Link to comment Share on other sites More sharing options...
piranha Posted April 24, 2017 Share Posted April 24, 2017 Hessin 2009 does not mention Tentaculites, instead describes Cornulites flexuosus from Georgian Bay. 2 Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 cornulites j.1096-3642.2007.00300.x.pdf Liam's thesis on Silurian problematica is a good read BTW 1 Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 corn 1 Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 Morfelt 1 Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 Fail_Vinn_Zaton2012tentacul.pdf 2 Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 5 minutes ago, piranha said: Hessin 2009 does not mention Tentaculites, instead describes Cornulites flexuosus from Georgian Bay. Hello again! You are correct - Cornulites flexuosus is indeed mentioned in the book - thanks for the heads-up! My specimen looks a tiny bit different - each segment almost seems to have a zig-zag pattern on its wider side - but that could just be my eyes playing tricks on me and/or the fact that it's not the best-preserved specimen. It's interesting that Hessin (2009) states that these animals "are considered by most paleontologists to be an extinct type of calcareous tube worm (annelid)" but that "the walls of the tubes are thick with a cellular calcium carbonate structure which has led some researchers to believe that they are a type of stromatoporoid or calcareous hydroid." So, maybe I did find a stromatoporid? Anyway, you've likely found out my specimen's identity since it's been found in the Georgian Bay Formation before, so thanks once again!!! Monica Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 page 225 etc is extremely informative,in the sense that it documents miscellaneous fossils which can/might be mistaken for gastropods!!!!! If anyone of us found one of those,"gastropod steinkern "would be the first hing to come to mind 1 Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 14 minutes ago, doushantuo said: cornulites j.1096-3642.2007.00300.x.pdf Liam's thesis on Silurian problematica is a good read BTW 10 minutes ago, doushantuo said: corn 9 minutes ago, doushantuo said: Morfelt 6 minutes ago, doushantuo said: Fail_Vinn_Zaton2012tentacul.pdf Hi again, doushantuo! Thanks for all of the links! I'll definitely have a look through them when I have the time since I'm pretty excited that I've found something new (for me) from the area - hooray!!! Monica Link to comment Share on other sites More sharing options...
Monica Posted April 24, 2017 Author Share Posted April 24, 2017 Just now, doushantuo said: page 225 etc is extremely informative,in the sense that it documents miscellaneous fossils which can/might be mistaken for gastropods!!!!! Thanks for this one, too! Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 those pdf are there for everybody,not just for you I'm looking at the miscellanous Stigmatellae definitions,but acanthopore and mesopore distribution.. gee,dunno. the taxonomy might be obsolete. I know of several cladistic analyses of Ordovician bryozoa.... Link to comment Share on other sites More sharing options...
doushantuo Posted April 24, 2017 Share Posted April 24, 2017 oh yeah:nice finds BTW. The odds of(for?) finding something like that near where i live are the same as Sheldon dissing the roommate agreement 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