Ottawa Marine Fossils

[Naf]

Hey folks!

 

It took some time but I've finally gotten around to uploading some pictures from my recent fossil ""hunt"! The quotations are there because the directions I left for myself from a prior trip included such extremely helpful tips as "left at the spooky demon tree". Turns out when you're a chicken a lot of trees look like spooky demons >.>  It was definitely more of a sad confused wander than a full on hunt...but I digress.

 

While I wasn't able to find the exact spot from before, I found an area with similar geological features, and after digging up about half a foot of loam around a small outcropping was rewarded with numerous individual rocks with all sorts of...things...all over them. I grabbed one giant 40lb chunk and a smaller one to play with and poke at to practice techniques. The smaller piece is on the bottom.

 

Both samples were taken within feet of each other in a public forest just outside Ottawa, Ontario. The smaller piece I put in a bowl of water and gave a good scrub down with a toothbrush (brings me back to my field school days >.>) The surface and reverse of both are shown and I can provide more detailed pictures if necessary!

 

I thought the crystallized shell things were pretty cool, there were quite a few more out there, but I'm completely unsure of what I'm looking at or if there was a way to extract them safely. I'm most curious as to what the circular things that litter the rocks are, but there seems to be a variety of other shells and tubey wormy things in there as well. Is there some sort of resource or database I could refer to for fossils from this particular time period/area? I'd feel bad constantly asking 'whats that!?"

 

Anything neat here worth poking at with some of my archaeological pokers or have I found myself some very interesting garden rocks!

 

Edited November 22, 2018 by Naf
More spelling/clarity

[Darktooth]

Looks like you have yourself some gastropods. The specimen in the second pic looks to be the best. Aleast two different types.

[Fossildude19]

@FossilDAWG

[Kane]

Very neat find! I've seen similar gastropod assemblages with this form of calcite in-fill just south of Ottawa toward Manotick. 

[FossilDAWG]

These gastropods are almost certainly Ceratopea canadensis.  Aggregations of this species are sometimes found in the Lower Ordovician Oxford Formation of the Ottawa area.  Keep an eye out for other fossils, especially very rare trilobites.  Any trilobite bits are likely to be of scientific importance.  I also found a large piece of a coiled nautiloid in the Oxford.

 

Here is a reference that discusses Ceratopea canadensis from the area:

Ellis L. Yochelson & M.J. Copeland (1974).  Taphonomy and taxonomy of the Early Ordovician gastropod Ceratopea canadensis (Billings), 1865.  Canadian Journal of Earth Sciences 11(1):189-207.

Abstract:

"Several hundred silicified specimens of Pleurotomaria canadensis Billings, 1865 and other rare fossils indicative of a late Canadian age have been collected from the Oxford Formation, southwest of Ottawa, Ontario. Redescription of this neglected gastropod species permits its assignment to the genus Ceratopea, even though no ceratopean opercula have been found.Rare faunal elements include ribeirioids and open coiled gastropods that may have lived, respectively, in and on a mud bottom. There is no evidence that they have been transported. It is suggested that Ceratopea canadensis lived on algal mats some distance away from the shore and from where it is now found. After death, the soft parts of this gastropod decayed and the heavy operculum rotted off. The lightened shell, filled with gas, floated shoreward, likely under conditions of relatively calm water. Discovery of opercula within the Oxford Formation would provide evidence to support this hypothesis."

 

Don

[Kane]

Supplementing Don's recommendation to be on the look-out for Oxford Fm trilo-bits, this article may be of some utility as well (click on LINK): 

 

Ludvigsen, R. (1979). Lower Ordovician trilobites of the Oxford Formation, eastern Ontario. Canadian Journal of Earth Sciences. 16: 859-865 LINK

[Naf]

Awesome, thank you all very much for the responses, looks like I've got some reading to do!

 

I marked down where I found these in slightly better detail than last time so when the snows retreat maybe I'll head out for a more intense hunt!