Finds from the Credit River in Mississauga, Ontario

[Monica]

Hello there!

 

I was inspired by @markjw to check out the Credit River here in Mississauga, Ontario (Georgian Bay Formation, Upper Ordovician) because where I normally hunt there are typically no corals and I'd love to add a couple to my collection.  Consequently, I went out for about an hour this morning before the family got up in order to try my luck, and I'm happy to say that I was successful!!!

 

Based on information provided by @FossilDAWG in other threads here on TFF, I think all of my colonial rugose corals are Favistina calcina - here are photos of three of my specimens:

 

Specimen #1 - side view:

 

Specimen #2 - top and bottom views:

 

Specimen #3 - top and bottom views:

 

more to come...

 

[Monica]

Specimen #4 - solitary rugose coral - Grewingkia canadensis?  Or is there not enough to be sure of its identity?

 

Specimen #5 - brachiopod - any idea as to its identity?

 

Specimen #6 - side and top view of something odd - perhaps a bryozoan or a sponge?  There are tiny holes if you can see it up close...

 

Thanks in advance for your help!

 

Monica

[markjw]

Fantastic! I love when you can see a lengthwise section of coral as well.

I also found an identical little sponge at Erindale Park.

 

Your corals are great.

[Monica]

5 minutes ago, markjw said:

Fantastic! I love when you can see a lengthwise section of coral as well.

I also found an identical little sponge at Erindale Park.

 

Your corals are great.

 

Thanks, Mark!

 

You were the inspiration for my outing this morning, so thanks for that, too! 

[Darktooth]

Nice finds Monica!

[Monica]

1 minute ago, Darktooth said:

Nice finds Monica!

 

Thanks, Dave!

[Mark Kmiecik]

I like corals -- Thanks for posting.

[Monica]

15 hours ago, Mark Kmiecik said:

I like corals -- Thanks for posting.

 

I like corals, too!  Thanks for responding 

[marguy]

Monica, these corals are real jewels! thank you for presenting us these finds

[Monica]

2 hours ago, marguy said:

Monica, these corals are real jewels! thank you for presenting us these finds

 

I was very happy to find them since corals are quite rare in the rivers/creeks I normally hunt in.  Hopefully one day I'll find even better specimens than these, but I'm happy with my finds for now 

[erose]

Really nice specimens.

 

[Nimravis]

Pretty finds Monica.

[MeargleSchmeargl]

Really take a liking for specimen 1. The way it goes from looking like a smoothed pebble on the side to having well defined rugose corals on full display is mesmerizing.

[RJB]

Hi Monica, im not much of a coral guy but youve got yourself some purty cool specimens! 

 

RB

[FossilDAWG]

I agree that the colonial corals are all Favestina calcina.  I don't think the solitary coral is a Grewinkia, as that genus is characterized by long septa that form a vesicular (spongy) structure in the center.  Streptelasma (likely S. divaricans) also occurs in the formation and is a reasonable possibility.  In Streptelasma the septa reach the center of the coralite and may twist around each other some, but the do not form a vesicular mass.

 

The last item is a bit of a mystery.  Perhaps if you wet the flattened surface the structure will be easier to.see.

 

The brachiopod is too covered up and the exposed part is weathered, so I would be just guessing at an ID.

 

Don

[Monica]

On 8/7/2019 at 1:20 PM, erose said:

Really nice specimens.

 

 

Thanks!  I've never found colonial rugose corals before so I'm pretty happy with what I've found at this location so far!

 

On 8/7/2019 at 1:24 PM, Nimravis said:

Pretty finds Monica.

 

Thanks, Ralph!

 

On 8/9/2019 at 3:43 AM, MeargleSchmeargl said:

Really take a liking for specimen 1. The way it goes from looking like a smoothed pebble on the side to having well defined rugose corals on full display is mesmerizing.

 

Me, too - I think #1 is my favourite because you can clearly see that it's a colony of rugose corals and not a tabulate coral (which makes it a new find for me). 

 

On 8/9/2019 at 6:52 AM, RJB said:

Hi Monica, im not much of a coral guy but youve got yourself some purty cool specimens! 

 

RB

 

Thanks, Ron!  I'm not used to finding corals so close to home, so even though these aren't in the best shape, I'm quite pleased with them, too!

 

On 8/9/2019 at 7:18 AM, FossilDAWG said:

I agree that the colonial corals are all Favestina calcina.  I don't think the solitary coral is a Grewinkia, as that genus is characterized by long septa that form a vesicular (spongy) structure in the center.  Streptelasma (likely S. divaricans) also occurs in the formation and is a reasonable possibility.  In Streptelasma the septa reach the center of the coralite and may twist around each other some, but the do not form a vesicular mass.

 

The last item is a bit of a mystery.  Perhaps if you wet the flattened surface the structure will be easier to.see.

 

The brachiopod is too covered up and the exposed part is weathered, so I would be just guessing at an ID.

 

Don

 

Thanks for chiming in, Don - your help with identifying my specimens is much appreciated (as usual!).

I'll try to get a better photo of the weird specimen (the last item) tomorrow...

[Monica]

Hi all including Don @FossilDAWG!

 

Here's a photo of the last/weird item with the flat surface wet - any ideas as to what it could be?

 

Thanks once again!

 

Monica

[FossilNerd]

On 8/9/2019 at 3:43 AM, MeargleSchmeargl said:

Really take a liking for specimen 1. The way it goes from looking like a smoothed pebble on the side to having well defined rugose corals on full display is mesmerizing.

I’m with you on this one! Love the preservation detail and the transition from pebble to coral. I would have it out on display if it were mine. 

[Monica]

43 minutes ago, FossilNerd said:

I’m with you on this one! Love the preservation detail and the transition from pebble to coral. I would have it out on display if it were mine. 

 

I am indeed going to add this specimen to my fossil display area - it's my favourite of the bunch that I found 

[markjw]

I went to Erindale Park on Tuesday and found nothing interesting in the promising gravel near the entrance. There were some good pieces under the footbridge in the Credit River.

Oddly, I found corals on the dirt slope adjoining Uof T Mississauga property along the footpath. Lots of rocks sticking out of the hillside. Nothing spectacular, but the surprising location made my trip worthwhile. Only 1 of those finds was of the quality you pictured above.

 

Previously, I got a big flat bryozoan fossilized around a rock under the footbridge:

 

[Monica]

Interesting bryozoan, @markjw!  With all of those "holes" it resembles the photo of Stictoporellina in Bill Hessin's book (2009).  Hessin states that this genus "is somewhat common in the Verulam and Bobcaygeon formations especially in the Lake Simcoe area" (page 108) - he doesn't mention the Georgian Bay Formation, but you never know!

 

Thanks for sharing! 

[markjw]

On 16/08/2019 at 9:07 AM, Monica said:

Interesting bryozoan, @markjw!  With all of those "holes" it resembles the photo of Stictoporellina in Bill Hessin's book (2009).  Hessin states that this genus "is somewhat common in the Verulam and Bobcaygeon formations especially in the Lake Simcoe area" (page 108) - he doesn't mention the Georgian Bay Formation, but you never know!

 

Thanks for sharing! 

That entry is the closest I could find. There is another apt description in another part of the book, but no image. Stictoporellina is top candidate for now, thank you.

[ynot]

Nice finds and report Monica!

[Monica]

9 hours ago, ynot said:

Nice finds and report Monica!

 

Thanks, Tony!