Pinniped And Porpoise Rostrum

[uncoat]

We recently got back from a collecting trip to the Oregon coast. Here are a few of the pieces we picked up. unidentified Miocene pinniped and porpoise rostrum. The porpoise rostrum was soft enough to quickly prep. We also found a larger bone in a very large concretion. When i took the photos i thought it might be part of a rib but after looking over the photos I'm not so sure.. It seems hollow and i don't believe ribs are hollow? Either way the thing weighed 70+ pounds and had to be left behind.. Maybe next time i will bring a better chisel and a rock saw. Anyone have any ideas on that one? I hope everyone is finding the time to get out and collect.

[Boesse]

Hey there,

Nice finds. The large bone in the block appears to be the lower jaw of a baleen whale - they look like a giant rib, but have a large hollow cavity in them. I've attached a figure from a paper I published recently.

Bobby

[uncoat]

Hey there,

Nice finds. The large bone in the block appears to be the lower jaw of a baleen whale - they look like a giant rib, but have a large hollow cavity in them. I've attached a figure from a paper I published recently.

Bobby

Hey thanks Bobby, yeah i was reading through your blog the other day when the forum was down and i was kinda thinking whale jaw. Have you seen associated bones in separate concretions in the same area? Its seems that right in this area there are a lot of large whale bone fragments in concretion of similar size. Do larger bones accumulate in certain layers?

- Nick

[Boesse]

Oh man, I wrote an entire thesis on the distribution and preservation of cetacean bones within marine strata. Yes - bones are often concentrated along certain horizons, probably due to slowdowns in the rate of sedimentation. Occasionally the break in deposition is long enough to form bonebeds like the Sharktooth Hill bonebed.