Hey there every peoples!
I have been so busy lately that i haven’t done a proper post in quite a while. I wanted to get one in before i shove off to Utah for a couple weeks. And i have the perfect subject to do it: fieldwork!
Ok I’m over blowing it a bit. I merely tagged along. Charles Powel,II of the US Geological Survey was searching for fossil invertebrates on the eastern side of Carrizo Plain National Monument. He was nice enough to invite me along and help him look for stuff to use in his research.
Chuck himself, showing one of the many uses for an ice axe
The fossils we were looking for were mostly molluscs who lived and died at the bottom of a shallow bay. Chuck was out to collect fossils to compare to a similar set found north in the Salinas Valley. The fossils from the Salinas Valley are from the west side of the San Andreas Fault while the fossils from the Carrizo Plain are on the east side of the fault. Chuck and a coleague hope that they can shed light on the movement of the San Andreas Fault.
I learned a lot from this little foray. I learned that invertebrate paleontology can be just as difficult as for vertebrates. For example, at the first locality we checked out, i walked right past a cache of fossils.
Believe it or not, those are fossils!
You have to know what to look for. Preservation at these localities sucks. What happened was water leeched through the sediment and dissolved the fossilized shells of marine invertebrates, leaving behind molds of said shells. But even then, bits of shell could still be found:
The partial shell of a Forerria, a chonch-like mollusc
Partial shell of Astrodapsis, an extinct sand dollar
A barnacle i found (top) compared with one sticking out of the hillside (bottom)
A largely complete clam shell. This was the best one we found at the site.
Afterwards we headed over to Panorama Point. While we found a big outcrop, preservation here was even worse. No shell was to be found, only molds. However, they were still useful as long as they retained the full shape. We found lots of clams, a couple burrows, and i managed to find a nice razor clam mold:
A nice part and counterpart mold of a razor clam
There was a third locality Chuck wanted to search, but we couldn’t find it. His map was over 30 years old and the last time fossils were collected at the site was in the 1930’s. There was a road that was supposed to take us to the site but it was nowhere to be found (that’s the main reason for our trouble). We trekked around a little bit but rather than get lost we decided to wrap it up.
People would think that looking for fossil invertebrates is easy and nothing to get excited about. Well as i just demostrated above it’s just as hard to find complete invertebrates as it is for vertebrates. For example, look at this beautiful Pecton on display at the Los Angeles Museum:
How many shell fragments did the paleontologist have to sift through before he found this fine specimen?
Invertebrates may not be as exciting or as impressive as the large vertebrates that dominate museum displays, but they are just as important. They can inform us about ancient climates, geologic movements, and other things (a display at the San Diego Natural History Museum discussed how marine invertebrates could be used to map the extent of San Diego’s Pliocene bay). But does this mean we should forsake the vertebrates? No! Vertebrates (big and small), invertebrates, plants… these are all records of past life. The all have something to say. They are all pieces of the same puzzle: pontificating on which is more exciting (ie “Yeah we have found dinosaurs in the Denver formation. Big deal. This is the real exciting stuff”- Kirk Johnson, in regards to fossil plants) or more important or who is overrated will not help us complete the picture. To put the puzzle together, we need all the pieces, big and small.
While they were small, incomplete fossils of invertebrates, i no less got that thrill of discovery in finding them. I have spent so many years dreaming of one day going out into the field and looking for the fossils that have occupied my mind my whole life. And now i have finally realized that dream. It was only for a few hours, but the rush was there. Hopefully this is the launching point for more field work to come (it even spawned a new catagory, one that may not see an update for quite some time).
Till next time!