Sunday, March 17, 2013

Oregon coast trip with Ray Troll and Kirk Johnson, part 2: fossil localities of the Newport Embayment

We got up early the following morning to prepare for a long day of field work. We had some ambitious plans: we were to check out three of Doug Emlong’s fossil localities, all in one day. This included an area south of Depoe Bay, and the well-known Moloch (pronounced Moolack) Beach north of the Newport Lighthouse. These localities are all exposures of various units deposited within the mid-Cenozoic Newport embayment, an ancient basin that occupied what is now the central Oregon coastline, from Waldport to Lincoln City (or further; I’m unclear as to the limits of the depositional package, but it certainly does not continue to Astoria, as mid-cenozoic rocks in this region are considered part of the Astoria embayment). Marine rocks in coastal Oregon have yielded a substantial assemblage of fossil marine mammals, among other marine (and terrestrial vertebrates). Indeed, we owe much of our knowledge of marine vertebrates from this time and place to the dogged perseverance (if not outright obsession or addiction) of Emlong, and other collectors who followed him like Guy Pierson and James and Gail Goedert. The three formations we visited were the ‘middle’ Oligocene Yaquina Formation, the late Oligocene-early Miocene Nye Mudstone, and the late early-early middle Miocene Astoria Formation. FYI, some paleontologists – myself included prior to this trip – assume that it’s Spanish in origin and pronounced “Yakeena”. Turns out it’s pronounced “Yakwinna”, and it’s named after the nearly extinct Yaquina Indians; an alternate spelling of their language is actually Yakwina. Anyway, now you know. There’s a Yaquina bay, Yaquina Formation, and the Yaquina lighthouse.

Ray and I discuss the finer points of desmostylian posture while Kirk does something practical.

Ray and I are still discussing desmostylian posture while waiting for a table at the Otis Cafe.

The spouting horn at Depoe bay, Oregon. We stopped to check this out on our way to the localities.

Before we left for the field, we drove from the Sitka Center to the local favorite ‘Otis Café’. Over an enormous breakfast consisting of the world’s best fench toast and bacon, Ray, Kirk, Sarah, and I discussed the intricacies of reconstructing the posture of desmostylians. Frank Boyden joined us a little late for breakfast. On a whim, Kirk asked the waitress if she knew who Emlong was – and as it turned out, her sister had been a girlfriend of Emlong’s. Apparently, he had asked her out after high school, and she wasn’t interested. He tried again after he got his first payment for his Smithsonian collecting job (which he started in 1967), and bought a car – and then she went out with him. I made sure to buy a T-shirt from the establishment before we left Lincoln County.

Kirk and I put together a plan for the day at our first stop.

Although we didn't find any fossils, a walk on the beach is likely to turn up all sorts of evidence of modern dead critters - a tufted puffin carcass, in this case. We spotted about a dozen seabird carcasses, including several puffins (Fratercula), murres (Uria), and cormorants (Phalacrocorax). 

Kirk has a habit of scampering up the nearest promontory.

Another puffin.

Our first stop was the Yaquina Formation. Emlong collected a number of significant fossils from the Yaquina – by far the most important of which is the type and only known specimen of the toothed mysticete Aetiocetus cotylalveus (not cotylaveus). The holotype skeleton was collected by Emlong in March 1964, and includes a well preserved skull, most of a vertebral column (39 vertebrae), 23 ribs, several loose teeth, part of a sternum, and several chevrons. Emlong originally considered it to be an archaeocete, given the presence of teeth and the lack of derived mysticete features. The remarkable thing is that Emlong, with zero technical background in paleontology – with encouragement from J. Arnold Shotwell and Remington Kellogg – described and named the fossil himself, in his only publication – less than two years after the fossil was dug out of the rock on the beach. It was later identified by Leigh Van Valen as a primitive baleen whale (but I’ll talk about that in a separate post). Other finds from the Yaquina Formation included the holotype of the primitive desmostylian Behemotops emlongi, named after Emlong (later synonymized with Behemotops proteus from the Olympic Peninsula in Washington; this taxon is sort of the “Pakicetus” of desmostylians), and skulls and mandibles of the more derived desmostylian (with a fabulous name) Cornwallius sookensis, which were eventually described by my good friend and colleage Brian Beatty (the species was originally named from the Sooke Formation on Vancouver Island, British Columbia). Lastly, the early pinniped Enaliarctos tedfordi was described from this locality by Annalisa Berta in 1991. Emlong collected the holotype of this specimen – a complete skull – in 1964. We looked around for about a half hour, and didn’t find a damn thing. Then again, the sand level was pretty high.

Sarah at Moloch Beach with the Astoria Formation in the background.

We moved to the next locality, a couple miles north – to examine additional outcrops of the Yaquina Formation and the late Oligocene-early Miocene Nye Mudstone. This was near the type locality of Enaliarctos mitchelli, which is from right around the Oligo-Miocene boundary. There was plenty of fossilized wood – probably limonitized or mildly pyritized, as indicated in Emlong’s paper. That’s about all that we found in either the Yaquina or the Nye, though. Despite a long history of important fossil discoveries from this locality, I was beginning to get disappointed with how poorly fossiliferous the localities were – I’m used to fossil localities in central California where literally hundreds of bones, teeth, and bone fragments are found for every skull that is recovered – and on a single trip, a hundred vertebrate fossils can be found after less than an hour of looking. We had visited two localities that had yielded several holotype specimens each, and not found a shred of bone.

 Sarah wading through a field of mostly unfossilferous boulders.

 Kirk attempting to crack a concretion the old fashioned way.

We left, hoping that a trip to Moloch beach would prove to yield some better vertebrate material. Moloch beach has an extensive exposure of the early middle Miocene Astoria Formation – which yielded one of the earliest discovered fossil marine mammals from the west coast – Desmatophoca oregonensis, an earlier relative of the large sea-lion like phocoid Allodesmus kernensis. Later, Remington Kellogg and Earl Packard described a new type of baleen whale from Moloch beach, which they named Cophocetus oregonensis. Later, several new pinnipeds were described from the Astoria Formation by Larry Barnes and colleagues: Pteronarctos goedertae, Pteronarctos piersoni, Pacificotaria hadromma, and Proneotherium repenningi; all of these, except P. goedertae, were found at Moloch beach. Subsequently, two more fossil pinnipeds were described from the Astoria Formation: Enaliarctos emlongi (possibly from the Nye Mudstone – near the Nye/Astoria contact) and the tiny phocoid Pinnarctidion rayi. These two were from a separate locality – where the bizarre “oyster bear” Kolponomos newportensis was discovered (…also by Emlong). Oddly enough, Enaliarctos emlongi is one of only two pinnipeds from that locality that don’t begin with P.

 Some beautiful bivalves from the Astoria Formation.

We found a few chunks of rolled bone fragments – but nothing really interesting. Fossil localities with marine mammals are usually pretty easy to prospect – because whales are freaking huge, and have huge bones. It’s usually not hard to find vertebrae and ribs of baleen whales, and again, I was struck by how rare vertebrate remains were. Sure, there were some nice mollusks – but compared to fossil localities in California, like the Purisima Formation at Capitola where there are tons of beautiful mollusks littering the beach – the Astoria at Moloch beach was sort of average in terms of the number of invertebrates. After an hour or two of searching, I finally spotted a huge bone – the first in situ specimen at the locality. It was a large (~1.5 meter long) mandible of a baleen whale, perhaps something like Cophocetus. It’s technically legal to collect concretions from the Oregon coast with vertebrate remains in them – but not to dig bones out from the cliffs or wave cut bench. None of this detracts from Emlong’s legacy – in fact, the inability of three vertebrate paleontologists and several amateurs to find much of anything at any locality after a day of winter field work only makes his discoveries more amazing. My suspicion – and Kirk Johnson’s – is that Emlong capitalized on the fact that concretions sit around for a long time, and nobody before him collected vertebrate bearing concretions in such a systematic manner. There must have been concretions which had accumulated on the beach for thousands of years, and Emlong and subsequent collectors have effectively collected most of that ‘lag’ of concretions, leaving little for current visitors.

Ray sketching Kent Gibson's billfish.

After leaving the beach, we visited the nearby home of local amateur fossil collector Kent Gibson, who had found a partial billfish skull in a concretion at Moloch beach (possibly from the Nye Mudstone). It’s some sort of a huge Aglyptorhynchus-like billfish. Kent had an impressive collection, including a beautiful little pinniped skull that could be fairly important, if it were prepared and placed within a museum collection. Ray – being a fish guy – was wanting to see the billfish and other specimens. Upon arriving at Kent’s house, we saw a yard littered with fossils. Ray borrowed some sidewalk chalk from Kent’s kids and started drawing an outline of the billfish’s body as it would have appeared in life, to scale, with the fossil in place. Altogether it was pretty neat. But, we were getting hungry and Frank Boyden had invited us to dinner at his awesome cabin, decorated with his artwork and the artwork of others. Frank showed us some parts of his collection, including original prints by late 19th century French ‘bohemian’ artist Odilon Redon. At one point, Frank needed to install a railing in his house – instead of installing any old railing, he went to the beach, got a stalk of bull kelp, and casted in bronze – and it is one of the coolest damn things I’ve ever seen. Frank showed us his printmaking studio, which was spectacular, and useful for me as an artist to learn about more involved artistic methods – pencil and paper is my bag, because it’s simple and primitive (and dirt cheap).

Frank's "cell phone"

We never got a break, even during dinner: Frank had all sorts of bits of animal skeletons. Here kirk and I puzzle over a large fish skull.


I don't remember what was going on here.

Next up: behind the scenes at the Oregon coast aquarium, Sea Lion Caves, and the conclusion of the trip

No comments: