SUMMER FINDS AT FAIRMEAD LANDFILL
Jeff Anglen serves as a lecturer in the Department of Earth and Environmental Sciences at California State University, Fresno. His contribution of the material for todays article is appreciated.
As my spring geology classes at CSU-Fresno were coming to a close, I was presented with the opportunity of being the head paleontology monitor at the Fairmead Landfill this past summer. I worked at the landfill as a part-time
paleontology monitor in the summer of 2006, so I was somewhat familiar with the site and its fantastic fossil resources. I specialized in the study of dinosaurs and crocodiles in the past so fossil mammals are not exactly my cup of tea, but the idea of several thousand fossil vertebrates within a half-hour drive from my house was just too tempting to pass up. I also suspected that if enough dirt was removed over the course of the summer, there might be a “mother lode” of fossils to be collected by summers end. I chose to study paleontology because of my love for fossils and field work and Fairmead Landfill provided both.
In the summer, part-time monitor Blake Bufford and I were finding fossils nearly every day, even if many of them were in poor condition. Mammal teeth are made of very hard materials, so they are among the most common fossils at the landfill and are preserved rather well. We found quite a few teeth from horses, camels, and mammoths. We also found several bone fragments from the lower limbs of horses and camels. There bones correspond to the ankle and wrist bones of people. I also found a proximal femur fragment from a mammoth, this is the upper end of the thigh bone where it inserts into the hip joint. We found two occipital condyles from horses, these are skull fragments that are located around the hole where the spinal cord enters the base of the skull.
Blake made the best discoveries of the summer though, two horse jaw fragments. Both had portions of the left and right mandibles as well as incisors still in their tooth sockets. Unfortunately the landfill’s heavy equipment damaged one of the specimens, but the other is in very good condition. It’s a shame when the excavation equipment hits a fossil hard enough to damage it, but if it were not for the landfill crew’s excavation we would not have the wonderful opportunity of finding anything at all, so we are grateful for their efforts. Mark Jones deserves special recognition for keeping us informed of the excavation plans and looking out for us when the temperatures hit triple digits.
In July and August, most of the excavation was at depth above the fossiliferous sediments so our luck ran cold. The temperatures went over 100 degrees a couple of times so we were more worried about staying safe than finding fossils on those occasions anyway. Fossil hunting is always a hit or miss proposition so we are prepared to have an unlucky streak from time to time. It gives us an opportunity to clean and analyze the fossils we have already found. One of my interests is the study of taphonomy, how fossils are buried and preserved. I analyzed the burial positions of all of the fossils we found this summer to see what I could learn about their preservation. The elongate fossils were buried mostly in horizontal positions and randomly oriented in all compass directions. This indicates that the bones were not aligned by the water flowing in stream channels or floods. This is an example of what a paleontologist can learn by studying the fossils in place and the surrounding sediments in which the fossils are buried.
Even though our luck ran dry this summer, it is still a very exciting time for paleontology at the landfill. As I am writing this article, my successor, Niranjala Kottachchi, is monitoring for fossils during the preparation of a new cell in the landfill. We hope to discover the continuation on the bone bed that was uncovered last summer!
Duane E. Furman