Recently, Ralph J., a Fossil Forum friend, had made a trip to Georgia to collect some fossils from the Conasauga Formation, which is Cambrian in age. After he had posted his finds from the trip, I expressed delight at the seeming abundance of trilobites in the mudstone-shale, and he very kindly offered to send me some of the trilobites and some matrix to split. I was absolutely floored with his generousity - and this was only exceeded by the size of the box. There will be enough for Deb and me to split for a while.
And none too soon, either! The forecast is calling for flurries this Friday, which hopefully does not prematurely bring closure to such a memorable 2017 collecting season. I am dimly holding out hope that there will be at least one day left where Malcolm and I can get out to Arkona... just one last kick at the can before the snows fly.
At the moment, I am completely buried under a lot of grading and other work, so this gift arriving in the mail was certainly a great respite. I have not yet had an opportunity to get at the matrix, but here is a four panel picture of the newly added species to my burgeoning collection, Aphelaspis brachyphasis.
The matrix itself has a kind of slick, smooth, almost velvety texture. It splits fairly easily, and has a nice olive and tan colour to it, some with a deep orange staining, sometimes yellow (a very colourful matrix!). This layer has virtually nothing else visible to the eye except for this species of trilobite, and more uncommonly small fragments of a very tiny agnostid trilobite that perhaps only a magnifying lens will be able to spot.
These guys can be pretty small. The biggest ones are about under an inch, with plenty of others barely a millimetre or so long. The preservation is new to me. The trilobites are replaced entirely by minerals and in-filled with a kind of mud, and so you may find more detail in the impression than in the positive.
I've made the attempt above to put one of the very tiny ones (~1.5 mm) under the digital microscope to show some of the diagnostic details. Not the best picture, but you get the idea. Once I find the time to go through the matrix, I may have some better examples to show - and even if not, these are welcome new specimens to the collection.
Stay tuned as I am expecting three species of trilobite from Bolivia, and eventually my air scribe to work on some of my previous finds in the hopes of discovering some surprises.