Hilton typically goes prospecting for mesozoic marine tetrapods and dinosaurs in California, and Neogene mammal bearing localities in Nevada. However, he did some fieldwork in the Purisima Formation at Point Reyes in the 1960's, and thus he has a soft spot for marine mammal remains.
After a few hours of looking, I finally spotted a concretion that looked like a fossil. Sure enough, there was some bone poking out of the sides. After a split second I was able to identify it as a sea lion (Eumetopias) femur. I got this puppy prepared just before SVP, and it is covered in fossil barnacles.
Richard Hilton fifty feet up a cliff of predominantly unconsolidated sand (read: not sandstone). This photo was taken nearly straight down.
Later in the day, I found a huge chunk of bone (as float) about 80 feet up a cliff. However, after spending an hour and a half looking, the three of us couldn't find the rest of the bone - we found two more pieces which attach well, but nothing else in the loose talus, or in the exposure. Perhaps it was the last remnant of something big that had eroded out of the cliff, and the rest of it had already continued down to the river below. It is a very small chunk of a very large scapula (best guess); it is difficult to say exactly what it is because of its incompleteness. However, there are two important aspects to this fossil: 1) Mysticete bones are extremely rare at this outcrop, and rare from Pleistocene deposits in general (at least in North America); 2) there are two very large shark tooth bite marks on this bone, which are subparallel (which means that tooth spacing can be determined) ; one of these marks is nearly 5 inches long! That'll make a good short paper some day.
Closeup of the strange trace fossils.
One prominent feature of this unit I found on my first visit here over a year ago were the presence of bizarre, spiky trace fossils. I've seen cross-sections of these in the Purisima Formation, but this is the only other unit I've seen these in (which also happens to be a marine, Neogene, blue sandstone deposited in the lower shoreface). F.A. Perry hypothesized in his UCSC senior thesis that these were larval chambers for some invertebrate, potentially calianassid shrimp, and that the little spikes were larval escape structures. Here at this Oregon locality they are preserved in 3D, so study of them from this locality may prove much easier than in the Purisima.
Wisps of dust from the overlying late Pleistocene terrace pour down as veils over the shelly early Pleistocene deposits.
Other stops on our trip were the Miocene St. George Formation near Crescent City, the Pleistocene Moonstone Beach Formation, and the Plio-Pleistocene Centerville Beach section of the Wildcat Group. We returned empty handed from these other localities.