2020 Ontario Trilobite Hunting

[Tidgy's Dad]

Good luck tomorrow! 

[Monica]

Happy hunting today, Kane!

[Kane]

What a remarkable day. Deb and I made the 1.5 hour drive to the Bois Blanc Formation site. There, we have the choice of going right to the strata, or to the already ripped up piles -- same material, either way. 

 

The more calcareous material is lumpy, bumpy, and filled with crinoids, trilo-bits, bryozoans, platycerid gastros, and giant rugose corals. I wish my iPad was not at the other side of one of the huge rock piles, because one of these single rugose was about the size of an average forearm. Just wow.

 

The calcareous material is very brachiopod poor, oddly enough. It is the easiest to work with, but trilobites are mostly just shredded Burtonops bits and really poorly preserved, shattered Anchiopsis. 

 

First up, check out this enormous gastropod. 

 

[Kane]

How about some coral? Oh my. And these were not the biggest,, either. Some of the split rocks were about dining room table sized, and would be littered in corals of all kinds -- syringoporid, tabulate, rugosa -- and particularly on a sandy layer where most of the matrix had worn away, leaving the corals standing out 3D.

[Kane]

Sort of like this. 

[Kane]

Some other sandy-facies goodies: 

[Kane]

Definitely a keeper platycerid.

[Kane]

An assortment of items I would stick in my pocket as the day went on. I think those bottom two are Pleurodictyum? If so, much larger than at Penn Dixie. 

[Kane]

So what about the bugs? Well, anything good will not be in the calcareous material. When Rolf Ludvigsen described the Bois Blanc as being "perversely tough," he was not exaggerating. This stuff is tough indeed. There are sometimes bedding planes, but they do not abide by what fossils are inside. Instead, be ready to shatter right through them. Also, there is no casual cracking of these rocks: each one is a solid time commitment, so if there is nothing showing, it could very well likely be a blank or filled with bits. 

 

Other times, the bugs show on the surface, and are usually too eroded to be of much appeal. An Anchiopsis tail:

[Kane]

One of my two trip-makers is this nearly complete Calymene platys. Sadly, a lot of the skin is in the impression. I took all the pieces home and may entrust someone to prep this as I am absolutely miserable on prepping glued down bugs. The worst. 

 

But check out that size. Wow. It looks very much like those Flexicalymene ouzregui from Morocco. And, just like the hard Devonian Moroccan material, a lot of the bugs only show as hairline, and almost never break neatly. 

[Kane]

The lesser Calymene. A headless ventral, and a ventral head. 

[Kane]

And the other trip-maker for me. What I very much suspect to be a piece of Terataspis grandis. Initially I was thinking pygidial spine, then a genal, given the crescentic shape... but I’m not fully certain (I’m thinking genal). And, possibly another fragment. Of course, when it comes to a trilobite of this significance, I'll ask @piranha to confirm my kill.  

 

I also encountered fragments of some of the other, more common bugs, but they weren't worth bringing home. When it comes to the Bois Blanc Fm, I can check off most of them from the list. The rock is brutally hard, but in the end it was definitely worth it. 

 

[Tidgy's Dad]

36 minutes ago, Kane said:

 

The calcareous material is very brachiopod poor, oddly enough. 

[Tidgy's Dad]

Splendid day out, some of those corals and the huge Calymene are outstanding. 

Still really enjoying this thread while I'm stuck in my apartment. 

[taj]

That was a splendid day to be outdoor , for sure ! Great finds !

[FossilDAWG]

Impressive assortment of fauna!  I'm envious that you are able to get out and hunt.  Glad you are having fun.

 

Don

[FossilNerd]

Nice finds! The coral (syringoporid?) half weathered out of the sandy layer would have been a trip maker for me! I love the way it is exposed. 

 

Fingers crossed that you found another Terataspis grandis! 

[Monica]

All great finds (especially the large gastropod and Calymene pygidium - wow!), but this one is my favourite:

[Peat Burns]

1 hour ago, Kane said:

1 hour ago, Kane said:

 

I wish my iPad was not at the other side of one of the huge rock piles, because one of these single rugose was about the size of an average forearm. 

First up, check out this enormous gastropod. 

 

 

And I wish we could have seen one of the monster horn corals

 

Great finds as usual.

[Malcolmt]

Looks very similar to my piece of terataspis 

[Kane]

3 hours ago, Tidgy's Dad said:

Splendid day out, some of those corals and the huge Calymene are outstanding. 

Still really enjoying this thread while I'm stuck in my apartment. 

Thanks Adam.  Sorry that the material didn't produce any lovely brachs (but it does seem you are having barrels of brachiopod fun in the Ordovician at the moment!). 

 

2 hours ago, FossilNerd said:

Nice finds! The coral (syringoporid?) half weathered out of the sandy layer would have been a trip maker for me! I love the way it is exposed. 

 

Now I feel silly leaving it in the field.  These colonies are ridiculously abundant!

2 hours ago, Monica said:

All great finds (especially the large gastropod and Calymene pygidium - wow!), but this one is my favourite:

 

Thanks!  And, actually you can see that it is much more than a pygidium -- it's effectively complete with the full thorax, but minus a bit off the top of the glabella (the head piece, seen in the first image, will be glued back on, and the remainder of it prepped).

 

The ramose bryozoans were relatively abundant in this material, vermiculating their way everywhere.  

2 hours ago, Peat Burns said:

 

And I wish we could have seen one of the monster horn corals

 

Great finds as usual.

I really should have taken that photo now!  I sometimes get into the mode where I can't put down the hammer to pick up the camera! In this case, the rock was at the top of a very tall pile, and it would have taken some ginger steps to bring it down to my "base camp" for photos. 

2 hours ago, Malcolmt said:

Looks very similar to my piece of terataspis 

You're right -- very close! Yours was a pygidial spine, whereas I'm thinking mine is a genal from here: 

[FossilNerd]

2 minutes ago, Kane said:

Now I feel silly leaving it in the field.  These colonies are ridiculously abundant!

Oh don't feel silly! We all have our preferences. Yours just happens to be of the buggy variety! You were blinded by the sight of the possible Terataspis grandis spine!    

[Kane]

Went back for an 8 hour shift at my Onondaga site yesterday. Mostly the same stuff as on previous trips, but with one new oddball, and a small "aha" moment. 

First up, the big brachs (+gastro steinkern) and an army of rostroconch. Below the rostros are tiny brachs -- I keep them if they are matrix-free and have both valves.

[Kane]

A noteworthy rostroconch before and after I freed it from most of the matrix. This one measures 4.5 cm wide, or shy of two inches. It is fairly robust. The "top part" comes off to show the detail inside. 

[Kane]

The usual anterior denticle brims of Odontocephalus.