Monica Posted March 17, 2020 Share Posted March 17, 2020 Hi all! After reading about @Kane's autumn trip to Ontario's Formosa Reef (Amherstburg Formation, Lower Devonian), I was inspired to find it and check it out myself. With the help of Ludvigsen's 1986 paper entitled "Reef trilobites from the Formosa Limestone (Lower Devonian) of southern Ontario," along with Google Maps' Satellite View, I was able to locate the reef, so Viola and I made the 2-hour drive yesterday to search the site for some new fossils. Here's Viola standing atop the reef: This was my first find of the day - a rock with a brachiopod AND a gastropod in it - woohoo!!! This was one of Viola's first finds of the day and probably her favourite - a large and beautiful chunk of tabulate coral: Here is a photo of Viola and I just before we left the site after about 3 hours of fossil-hunting: Photos of the fossils to come... 19 Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 Trilobite material: Specimen #1: I'm assuming this a part of a trilobite, but I'm not sure. Hopefully @piranha and/or @Kane can provide some insight: Specimen #2: a free cheek of Crassiproetus crassimarginatus: Specimen #3: a cranidium of Crassiproetus crassimarginatus: Specimen #4: a pygidium of Crassiproetus crassimarginatus: Specimen #5: a pygidium that I think is from Mannopyge halli but I'm not sure: More fossils to come... 20 Link to comment Share on other sites More sharing options...
Manticocerasman Posted March 17, 2020 Share Posted March 17, 2020 nice report quite a lot of trilobite stuff 1 growing old is mandatory but growing up is optional. Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 Mollusc material - I was hoping to find some specimens as stunning and large as @Kane found back in the autumn, but it just wasn't meant to be: Specimen #6: an imprint of a slightly curved orthoconic nautiloid: Specimen #7: an actual specimen of a slightly curved orthoconic nautiloid: Specimen #8: a small chunk of an orthoconic nautiloid that's not curved: Specimen #9: a couple of gastropods: More fossils to come... 14 Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 More mollusc material: Specimen #10: a rostroconch (I think): Specimen #11: a rostroconch imprint (I think): Unknown material: Specimen #12: this is on the same rock as Specimen #11, and it may be nothing, but I thought I'd post a picture of it just in case it's something - it appears to have some curved layers to it: Coral material: Specimen #13: "front" and "back" of a nice chunk of tabulate coral: Thanks for having a look! Monica 18 Link to comment Share on other sites More sharing options...
hokietech96 Posted March 17, 2020 Share Posted March 17, 2020 Looks like you had a lot of fun yesterday!! Great pictures! 1 Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 13 minutes ago, Manticocerasman said: nice report quite a lot of trilobite stuff Thanks, Kevin! Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 Just now, hokietech96 said: Looks like you had a lot of fun yesterday!! Great pictures! Thanks, Mark! We did have fun yesterday - the weather was cool but sunny and dry so it was perfect for fossil-hunting, and we encountered no one so it was a great way to spend the day given the current recommendations to isolate ourselves from others due to coronavirus. We'll definitely check out this location again in the future! Link to comment Share on other sites More sharing options...
Jeffrey P Posted March 17, 2020 Share Posted March 17, 2020 Congratulations. Looks like you and Viola had an excellent time on a beautiful sunny day. Love the big tabulate coral (Favosites?) and those partial trilobites look interesting- different species than the ones I'm used to finding in the Devonian. 1 Link to comment Share on other sites More sharing options...
Kane Posted March 17, 2020 Share Posted March 17, 2020 Good show. You may find J.A. Fagerstrom's paper on the reef helpful. Kenneth Klein has also committed time to the type section. More recently, a dissertation by Kim Kyou performed a section-by-section analysis (10 in total from leeward to windward side). Kyou, K. (1992). A microfacies study of the sedimentology and diagenesis of the Formosa Reef Limestone (Middle Devonian), southwestern Ontario. And, to place it in context, Shuo Sun's even more recent study: Sun, S. (2018) Stratigraphy of the Upper Silurian to Middle Devonian, Southwestern Ontario Once we get our new car, we have designs on visiting there soon in addition to a few other unlisted outcrops of the same. Despite how distinct the Formosa reef bioherm is from the surrounding Amherstburg strata, it does not enjoy an official status as a stand-alone member even if it seems to deserve it! 4 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
Fossildude19 Posted March 17, 2020 Share Posted March 17, 2020 Great report, finds, and pictures, Monica! Thanks for posting them. 1 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
minnbuckeye Posted March 17, 2020 Share Posted March 17, 2020 I see that Viola is standing above a large quantity of matrix worked over, in the first picture. Is her middle name "Kane"? NICE Finds!!! Mike 3 Link to comment Share on other sites More sharing options...
Malcolmt Posted March 17, 2020 Share Posted March 17, 2020 Way to go... I have never been might try it one of these days 1 Link to comment Share on other sites More sharing options...
Ludwigia Posted March 17, 2020 Share Posted March 17, 2020 @Monica Thanks for the great report. I'd love to have a peek at that site if the Corona thing has subsided in time for my planned visit mid June. 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 1 hour ago, Jeffrey P said: Congratulations. Looks like you and Viola had an excellent time on a beautiful sunny day. Love the big tabulate coral (Favosites?) and those partial trilobites look interesting- different species than the ones I'm used to finding in the Devonian. It was a beautiful sunny day! It was so nice to get outside and away from everything for a bit. If travel by car within the province isn't restricted during this March/COVID-19 Break, I think Viola and I will try to make it up there one more time. 1 hour ago, Fossildude19 said: Great report, finds, and pictures, Monica! Thanks for posting them. Thanks, Tim! 1 hour ago, minnbuckeye said: I see that Viola is standing above a large quantity of matrix worked over, in the first picture. Is her middle name "Kane"? NICE Finds!!! Mike Hi Mike! I imagine that the large number of loose rocks were leftovers from when @Kane was there in the fall - Viola and I spent about half of our time looking through those pieces, and then the other half of our time hammering some rocks ourselves. While I pulled rocks out of the reef, Viola hammered some of the bigger pieces to see if anything was hiding inside. It was a team effort. Link to comment Share on other sites More sharing options...
piranha Posted March 17, 2020 Share Posted March 17, 2020 This Acanthopyge contusa hypostome is especially exciting ... Congrats on finding it! attached for comparison is the hypostome of: Acanthopyge haueri Thomas, A.T., Holloway, D.J. 1988 Classification and Phylogeny of the Trilobite Order Lichida. Philosophical Transactions of the Royal Society of London, Series B 321:179-262 PDF LINK 7 Link to comment Share on other sites More sharing options...
Nimravis Posted March 17, 2020 Share Posted March 17, 2020 Great finds Monica, glad that you and Viola got out into some fresh air. 1 Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 1 hour ago, Kane said: Good show. You may find J.A. Fagerstrom's paper on the reef helpful. Kenneth Klein has also committed time to the type section. More recently, a dissertation by Kim Kyou performed a section-by-section analysis (10 in total from leeward to windward side). Kyou, K. (1992). A microfacies study of the sedimentology and diagenesis of the Formosa Reef Limestone (Middle Devonian), southwestern Ontario. And, to place it in context, Shuo Sun's even more recent study: Sun, S. (2018) Stratigraphy of the Upper Silurian to Middle Devonian, Southwestern Ontario Once we get our new car, we have designs on visiting there soon in addition to a few other unlisted outcrops of the same. Despite how distinct the Formosa reef bioherm is from the surrounding Amherstburg strata, it does not enjoy an official status as a stand-alone member even if it seems to deserve it! Thanks for the article recommendations, Kane! And thanks for posting your fall field trip, because that's where I got the idea to visit the reef! By the way - did you have a look at my fossil photos? Did I identify the trilobite pieces correctly? And did I actually find a rostroconch and an imprint of one? 1 hour ago, Malcolmt said: Way to go... I have never been might try it one of these days Hey Malcolm! It was very easy to get to the reef - it took 2 hours of driving, so a little less time than it takes to get to Arkona/HH from where we live. It was well worth the drive. 51 minutes ago, Ludwigia said: @Monica Thanks for the great report. I'd love to have a peek at that site if the Corona thing has subsided in time for my planned visit mid June. Hi Roger! If everything re: coronavirus calms down and you actually make it here in June, it would be a great place for you to visit! Perhaps we can go together...? I could bring a picnic lunch (with brownies for dessert, of course ) 1 Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 10 minutes ago, piranha said: This Acanthopyge contusa hypostome is especially exciting ... Congrats on finding it! attached for comparison is the hypostome of: Acanthopyge haueri Thomas, A.T., Holloway, D.J. 1988 Classification and Phylogeny of the Trilobite Order Lichida. Philosophical Transactions of the Royal Society of London, Series B 321:179-262 PDF LINK WOW!!! Thanks for the identification help!!! In Ludvigsen's 1986 article mentioned in my initial post, there were no hypostomes included for Acanthopyge contusa, so I didn't know what it was. Now I do, thanks to you!!! Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 11 minutes ago, Nimravis said: Great finds Monica, glad that you and Viola got out into some fresh air. Thanks, Ralph! It couldn't have been a better day! (Well, actually it could've been better, if I had found a large, nice cephalopod! But I'm not complaining, especially after finding out that I found a hypostome from a "rare" trilobite species from the reef!!! I'm on Cloud 9 now!!! ) 2 Link to comment Share on other sites More sharing options...
Kane Posted March 17, 2020 Share Posted March 17, 2020 14 minutes ago, Monica said: By the way - did you have a look at my fossil photos? Did I identify the trilobite pieces correctly? And did I actually find a rostroconch and an imprint of one? The trilobite IDs are correct. And, yes, the rostroconchs are correctly identified. 2 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
Monica Posted March 17, 2020 Author Share Posted March 17, 2020 1 minute ago, Kane said: The trilobite IDs are correct. And, yes, the rostroconchs are correctly identified. Thanks once again, Kane!!! That's my first rostroconch (and so here is my happy dance: ) 2 Link to comment Share on other sites More sharing options...
piranha Posted March 17, 2020 Share Posted March 17, 2020 For your records here is a printable chart of the hypostomal biometrics of Acanthopyge: HL = sag. length of the hypostome HLb = sag. length of the hypostomal body HLp = length of the posterior hypostomal margin HWa = tr. width of the anterior hypostomal margin (at anterior wings) HWmax = maximal tr. width of the hypostome (at shoulders) HWp = tr. width of the hypostomal posterior margin HWba = maximal tr. width of the anterior lobe of middle hypostomal body HWbp = posterior tr. width of the posterior lobe of middle hypostomal body figure from: Budil, P., Frýda, J., Chatterton, B.D E., Corbacho, J., Vokáč, V. 2016 Intraspecific Variability in Trilobite Acanthopyge (A.) haueri (Barrande, 1846) from the Middle Devonian (Eifelian) of the Barrandian area (Czech Republic). [Innerartliche Variabilität bei dem Trilobiten Acanthopyge (A.) haueri (Barrande, 1846) aus dem Mitteldevon (Eifelium) des Barrandiums (Tschechien).] 3rd German Conference on Trilobites. [Ampyx-Verlag Publishing, Berlin, October, 8th and 9th 2016]. Abstracts of Lectures. pp. 8-11 2 Link to comment Share on other sites More sharing options...
ricardo Posted March 17, 2020 Share Posted March 17, 2020 46 minutes ago, Monica said: That's my first rostroconch 1 Link to comment Share on other sites More sharing options...
Ludwigia Posted March 17, 2020 Share Posted March 17, 2020 1 hour ago, Monica said: Hi Roger! If everything re: coronavirus calms down and you actually make it here in June, it would be a great place for you to visit! Perhaps we can go together...? I could bring a picnic lunch (with brownies for dessert, of course ) Sounds good to me 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
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