posting this on the final day of a three day dig at Penn Dixie in Hamburg, NY. Earlier in the week I dug with Fossil Forum friends in the Thedford area, and have been amassing finds over several trips. No pics of those hunts yet, but that will happen once the season is over.
We moved a lot of rock this weekend, and found a lot of trilobites. Pics of those when I get the chance. For now, site pics to show our work.
This shows the state of the dig area cleared out after Friday when I joined the other crazy Canadians. As soon as I got there, the human backhoe that I am went right into ripping out large slabs. The fresh stuff is where the best preserved fossils can be found, as opposed to the stuff that has been left to weather out. We do serious earth moving! The trilobites appear mostly at the Smoke’s Creek layer of the Windom Member, or the bottom 15 cm from the contact with the Bayview, just below the water table.
By the end of Saturday, it was mostly just me and Deb, with Jay popping by. Thanks to him for supplying me with wedges. I carved out the slabs while Deb broke them down. Pictured above is the view from one end of the excavation. I managed to double the area (to the shovel handle in the background). The photo hardly does the size of this much justice.
There are a lot of fossils to photograph (about two 5 gallon buckets so far), giving me a lot of winter prep material. This one above is among the largest Eldredgeops rana trilobites that can be found here. This is going to prep out beautifully. A semi-prone position with pygidium tucked underneath. Rollers are common, but prones are not as frequent. I also found a Bellacartwrightia (looks like a Greenops on steroids) in ventral position. Lots of rollers and prones were found.
Some snaps of me caught by our shutterbugs on the Friday. Top two photos by Monica P., and bottom two by Ken M.
And this is how we left the place on the Sunday. Some serious excavation as about 250 cubic metres of rock were extracted and split.
Several buckets of goodies were collected, and these are a few of the better pieces. These are being kept as-is until winter prep time.
Full prone Eldredgeops rana in an assemblage with partials/moults of similar sized specimens.
Ventral side Bellacartwrightia sp. with doublure and intact left genal spine in evidence. Although a ventral prep is possible, I may stabilize this and prep it dorsally. It is uncertain if this is complete beneath the matrix, or just the cephalon.
Pygidium showing of a Greenops sp. Unclear yet if it continues into the rock, but the presence of thoracic pleurae is a positive sign. Sadly, some of the lappets are missing. These asteropyginae trilobites are far more delicate with thinner cuticle than the Eldredgeops rana, and so are more prone to disarticulation due to hydrodynamic forces
Two prones. The one one the left will be an easy prep. The one on the right was Deb's first in the field repair. She had accidentally flicked off the piece (shown with the whitish residue of cyanoacrylate) and I miraculously pulled it out as the first shard from the muddy, opaque water where it fell! It has not been reattached incorrectly; it has become disarticulated at the fourth pleural segment, possibly on account of compaction (which has also flattened it).
Two semi-prones. The one on the left is missing a bit of the glabella.
Assortment of rollers and semi-prones. Unless the rollers appear as more than one in the matrix, I tend to free them from their shale confines.
Although the split sheared the cuticle, I kept this complete roller on account of the large calcite grains in evidence.
Another full, albeit small, prone to prep. On the right is what remains of the throrax of the rare Bellacartwrightia sp.
In all, not a bad few days, but far from my best haul from this location. Gregarious trilobite assemblages were not much in the offing as we chased through the slabs for pulses in the Smoke's Creek layer of the Windom, coming up with a lot of very dense, blank or mostly coral-littered shale with no apparent bedding planes. Without the latter, it becomes mostly guess-work and luck with the hammer to bash the slabs open at the right spot.
My next post will follow the process of preparing my largest bug from this dig, and then it's off to Bowmanville for the biannual Ordovician quarry visit in search of Isotelus and Ceraurus.