2020 Ontario Trilobite Hunting

[Kane]

It was Coronura day, but only tantalizing bits. The deposition conditions are just not at all right to preserve these intact. 

[Kane]

The minor "aha" moment. What I assumed were Anchiopsis may in fact be Odontocephalus. The reason being is the pygidial caudal spine terminating as a notched "prong" rather than a sharp point. Also, pygidial width does not seem the best match. I had assumed that the delicate nature of the spine was the culprit in why they appeared "broken off," but after looking over every specimen I've pulled from this location where the spine was relatively intact, the notch is present. 

[Kane]

For comparison, the Anchiopsis I found at my nearby site, and the Odontocephalus at the Onondaga location:

 

In the absence of Anchiopsis, I can likely narrow down the age of the materials a bit better to be in the upper Moorehouse Mbr - Seneca Mbr. This is equivalent to the Dundee Formation (which is still equivalent to the Onondaga limestones outside of Ontario). 

[Kane]

And now for the curve ball. As I was happily splitting my rock and putting aside the occasional fragments of Coronura and Odontocephalus, I encountered this. Initially I assumed it was just another Pseudodechenella, but something was not quite right when I inspected it closely. The appearance of nodes and the pygidial rib termination suggest Mystrocephala. Of course, that is only reported in Amherstburg Fm rocks, and if there are no reported Coronura nor Odontocephalus in the Amherstburg. This would possibly extend the geologic range of this species. But then again, I've found Trypaulites sp. in Amherstburg materials as well. It just goes to show we need much more research on Devonian Ontario bugs! In fact, the range of Coronura and Odontocephalus goes back as far as the Bois Blanc Fm, and if we consider the Amherstburg contemporary with the Edgecliff and/or Nedrow Mbrs of the Onondaga, there is a possibility they could appear there. 

 

The site is becoming a little less viable these days on account of rising water levels. This is a good and bad thing. It is obviously bad in the short-term for collecting. It is beneficial insofar as these rocks, in their normal state, are brutally dense (and this is the case for the rock above the highest watermark). So, when they are submerged for a year or more, they "soften up" a bit, forming cracks. As the water levels rise for the season, there is not much time left. But, by autumn the levels should once again subside. 

[Peat Burns]

8 hours ago, Kane said:

Went back for an 8 

[Kane]

Returned recently from an overnighter trip to the Bois Blanc Formation. I am still in the process of photographing finds (I brought home a bucket, a flat, and two backpacks full). But first, to set the mood: our campsite at twilight: 

[Kane]

Up first, the non-trilobitic items. A giant rugose coral to the left of the glove, a neat piece that looks like a modern day hive has been built on a plank, some worn pieces from the arenaceous hardground, and two complete double-valve brachs (brachs are rare in this material). 

[Kane]

Heartbreaker Calymene platys, but the last one with the pygidium showing still extends into the rock. My scribe will determine if it is complete. 

[Kane]

A wee Burtonops, quite possibly complete. Only time at the bench will say. 

[Kane]

Venturing into the hummocky material, we stumbled upon what might have been a Terataspis moulting ground, or just the serendipity of tidal sorting. Either way, this is hardly representative of the abundance of their fragments. We encountered likely thousands. These are all quite murky as I'll need to apply the scribe, but there is even a cross section in the mix.

[Kane]

And more. 

Again, a bit tough to make out. Also, the pictures do no justice to how robust trilobites can be in these layers. 

The common theme here is: I have some scribin' to do!

[Malcolmt]

Wow! looks like you and M. Had a good one

[Kane]

This is the smaller of the two glabella I found. I have the skin/counterpart in another rock. The other example I haven't photographed yet, but it is bigger than a golfball, nearly perfectly round. 

 

Bear with me... I have other stuff from this trip to get through, and then prep. One rock was so abundant with them, that some layers may even need to be sacrificed to preserve the best of the bunch. 

[Peat Burns]

33 minutes ago, Kane said:

 

[Tidgy's Dad]

Marvelous. 

[Kane]

1 hour ago, Malcolmt said:

Wow! looks like you and M. Had a good one

We had an absolute blast. He came away with a lot of goodies, too. Prepping this stuff will be slow and tricky as this stuff is tough and sticky!

1 hour ago, Tidgy's Dad said:

Marvelous. 

Thanks, Adam.  I'm still baffled as to why the brachs are so sparse in this material. Perhaps those nasty big trilos were eating them!  

[Darktooth]

Well someone has been keeping very busy lately! Good for you Kane! Looks like the year is off to a good start, fossil wise.

[FossilNerd]

Nice finds as usual Kane, but you do have your work cut out for you once you get home! 
 

5 hours ago, Kane said:

a neat piece that looks like a modern day hive has been built on a plank

5 hours ago, Kane said:

Neat is an understatement! Wow! 

 

 

[Kane]

11 hours ago, Darktooth said:

Well someone has been keeping very busy lately! Good for you Kane! Looks like the year is off to a good start, fossil wise.

Since March 7th.

It is day 55 of this season and ongoing project. I've managed to get out 20 of those days, according to my field notes. I'm back to work for a week, and then it will be back out again!

9 hours ago, FossilNerd said:

Neat is an understatement! Wow! 

That was another that didn't come home with me, but this one (and the other big colony you pointed out last time) both went with my field comrade, so they have a happy home now.  

[FossilNerd]

4 hours ago, Kane said:

That was another that didn't come home with me, but this one (and the other big colony you pointed out last time) both went with my field comrade, so they have a happy home now.

As long as someone took those beauties home and they don’t weather to dust, I’m happy.  

[Kane]

Spent a good chunk of today going through the previous day's finds, and doing some preliminary prep. 

Here's a cross-section of a fully inflated Terataspis glabella:

[Kane]

Two works in progress. I am not entirely sure on the morphology of the first one, so I'm flying blind -- something you never really want to do while prepping. The second just needs the "pockets" dug out on the two spiny branches. Using a scribe to do that is not advisable as the vibration could shake the other pieces loose.

 

These are not tiny fragments. 

[Kane]

A shame that the photo flattens this glabella, but this one is robust and spherical. It took me an hour to get this far with abrasion and very light scribing. I'm not yet sure which direction it is facing, so the going is slow and nervous. For added joy, there is some sticky calcite, too. 

 

There are a few other very large rocks that are full of parts, some of which seem to be connecting to each other. This is not going to be easy, even under the scope.  

[Kane]

A better shot of the glabella area in progress with the Olympus TG-5 + the Burtonops I'm also working on. It is indeed Burtonops cristata as opposed to Viaphacops pipa due to the presence of nodes on the axis, which appears on the juveniles of the species in lieu of a short medial spine. 

[Monica]

Beautiful Burtonops, Kane - great job finding and prepping it!