We just got back from ten lovely days in Montego Bay, and although the trip was not about fossils as much as it was about indulging in a lot of sun, sand, and recovering from a hectic semester, there were a few accidental fossil moments.
Much of the rock in Montego Bay is limestone dating from between the Mesozoic to Cenozoic, and is dominated by corals - just as coral reefs dominate there today. After I went snorkelling in a living coral reef, our boat docked at Margaritaville where, just outside the club, there was a large shelf of limestone filled with fossilized coral colonies as pictured here.
The corallites on this one are very finely detailed. So I did manage, with the aid of a hand-sized rock, to hammer out a few specimens as souvenirs.
Due to the abundance of the local limestone, it is commonly used as a building material.
A gastropod fossil.
An oyster shell fossil.
UPDATE: Upon my return home, there was a package waiting for me from the UK. My Forum friend John sent me a lovely little gift with a card, some whiskey, and this Silurian trilobite piece from Wren's Nest in Dudley.
On Sunday, I had an opportunity to dig in the south pit for about 6 hours. The going wasn't easy: it was cold, for one. And it was very mucky. My goal was to locate full specimens of the two trilobites Crassiproetus canadensis and Basidechenella arkonensis. I have only found fragments in the past, and they occur in the Hungry Hollow Member of the Widder Formation along with Eldredgeops rana and a zillion corals in the coral biostrome. In some cases, there is more coral than matrix! Finding a full one in that layer is not easy as they usually occur as disarticulated fragments.
Arkona's south pit in the morning. There were patches of ice about.
It's early in the trip because I can actually see my boots. By the end of the day, they will be covered in gloopy mud. By my boot is a medium sized coral "pie." I don't really pick up corals anymore.
This is the bench where I've set up for the day. The goal will be to dig into it rather than widen it. It looks quite nice and clean here, but after about an hour the underground water was seeping out and turning the whole bench into orange-grey-brown sucking mud. There were a few mudslides and a rock slide.
It's hard to tell because of all the mud obscuring this rock, but there is a trilobite fragment in here (the darker brown bit in the upper centre). Whenever I encountered a fragment, I put it in the bucket for closer investigation at home. I also brought a spray bottle so that I can see what was under the mud.
So this is what I was dealing with. The rock at the top eventually gave way. The matrix itself is either concrete hard coral cement, or comes out mushy and flaky, but not a lot in between. It is, however, easy to work with on the prep bench. By this time, I'm covered in mud. My gloves are just floppy mud mitts, and my tools are caked. I had to go to the river and wash them off halfway through the day.
Another early win, of a sorts. This is a piece of Eldredgeops rana cephalon.
Thorax and pygidium of a Basidechenella peeking out of the matrix. Into the bucket it goes in the hopes I can discern if it will be a complete specimen.
The cephalon of another Basidechenella. As before, into the bucket for closer inspection at home.
Sometimes one has to chop through a lot of coral. This one just kept going and going. It was about well over two feet in circumference. Here I am chopping out chunks of it to free up the layer.
A chunk of that tabulate coral. Overall, it was a frustrating, cold, muddy day where I didn't have too much to show for it - this being likely my last trip of the year, and thus not ending on a high note. I collected a lot of the usual Arkona stuff like crinoid ossicles, etc., but even scanning the Arkona mud-shale was not being generous as it was all swollen with moisture.
I always collect these when I find them. This is the gastropod Platyceras conicum, which can be easily distinguished from the more snail-like Platyceras arkonense by virtue of its cone-like shape. This one is of a fairly good size and condition.
The sad news is that none of the trilobites turned out to be complete. The ones on the top and the left are Basidechenella, while the one on the right is Crassiproetus.
Using some tools to expose the trilobite a bit more, a closeup of the most complete Basidechenella I found that day.
A closeup on the other side of one of these rocks reveals the pygidium of a Crassiproetus.
So no big wow specimens pulled out this trip, but as my friend Tim says, "a bad day fossil hunting is better than a good day at work."
Until next time.