Jaw Bone Segment

[Phoenixflood]

Harry is like me. Half glass of water anyone?

We all have things to learn and no one can know everything, not even those who are at the highest level in their field. Take everything with a grain of salt, even expert IDs. Check with a variety of sources. You seem to be on the right track. Either way it is a cool find and you are very lucky to have come across it. I hope you have many more finds.

[TourmalineGuy]

Straus,

Harry gave a ton of very helpful advice here (some that I could, admittedly, follow better at times).

There is a lot to learn and at times it can be overwhelming. I started seriously collecting/researching fossils less than a year ago and this forum has been invaluable to the process.

As said previously, keep us informed!

Also, perhaps you could show us some of your other fossils (People around here seem to like fossils...)

Roddy

[siteseer]

Goodness! Don't be scared off, 'Straus'! I think that your experience with this jaw is quite instructive in a number of ways. You are not the only newbie reading this thread, nor are the lessons restricted to newbies. Thank you for bringing the fossil to our attention.

Professional paleontologists are just human . . . no more and no less. They feel the pressure of our expectations. We expect them to know the answers to our questions, and they want to meet those expectations. Maybe Bill Orr didn't want to disappoint you, 'Straus', with a more-appropriate "I don't know."

Whatever happened, it's been interesting to search for the facts in this case. That great western hero (or is it hero of great westerns?), Ronald Reagan had it about right: "Trust, but verify!" There is no substitute for your own critical observations.

The identification of your jaw may never be more than tentative or probable. You can approach the challenge from a biostratigraphical angle. Determine the age of the stratum from which it was eroded (someone said Late Miocene, I think). Once you know the age, find out what animals have already been identified from that age/stratum in Oregon. (The probability is that this jaw does not represent a first record of the taxon.) I think you should pay special attention to the artiodactyls.

Bill Orr may have access to a comparative collection which would be useful. No small part of your challenge is that no one puts much value on toothless jaws. It's unlikely you'll find a scientific illustration of a jaw with all its teeth broken away. Use a caliper to note some dimensions -- length of tooth row, length and width of m2, width and depth of the mandible under m2 -- so that you can compare these with any prospective match.

If you take on this challenge, you'll be amazed at how much you can learn and at how quickly you can learn it. Let us know how the research is going. Good luck!

-------Harry Pristis

Harry and Straus,

Dr. Orr is not a mammal expert. I read "Oregon Fossils" and noticed several errors:

p.173 - referred to Ziphius, a beaked whale, as a "long-nosed porpoise," which doesn't sound like a big deal but these cetaceans are in separate families, so to a biologist, it's like saying a wolf is a member of the cat family.

p. 186 - called Patriofelis "a cat" even though it is actually a creodont (an extinct group that also included the better-known hyaenodonts).

p. 197 - referred to the Dermoptera as "lemurs." It is true that they are called "flying lemurs" which mammalogists understand as not true lemurs (just an unscientific nickname) - a completely separate order of mammals.

p. 207 and 210 - referred to dromomerycids as "primitive cervids" when they were actually only distantly related to deer (dromomerycids had permanent bony horn cores - deer have antlers that are seasonally shed and regrown). That's somewhat of a fine point but one he should have made clear if he's going to talk about them.

p. 209 - said that bears, raccoons, and dogs...descended from "canids" like Amphicyon and Hemicyon. However, Amphicyon and Hemicyon were not canids but amphicyonids, a separate now-extinct carnivoran group. Canids (the dog family) and amphicyonids evolved separately during the Eocene.

There are a few other statements I question but haven't gotten around to researching.

Jess

[Straus]

Hi guys, I do not have calipers but I have really studied photos of a lot of jaw bone fossils today (I'm sure you guys have all found calphoto.com already)

I tried to look very carefully at the shape of the teeth (since I don't have crowns), the shape of the roots and the shape of the jaw. What do you think

about the mandible of a tapir?

[Harry Pristis]

Hi guys, I do not have calipers but I have really studied photos of a lot of jaw bone fossils today (I'm sure you guys have all found calphoto.com already)

I tried to look very carefully at the shape of the teeth (since I don't have crowns), the shape of the roots and the shape of the jaw. What do you think

about the mandible of a tapir?

Hi, 'Straus' . . .

You can buy an adequate, 6-inch digital caliper from China for less than $15.00, probably less on the West Coast. I got one at Harbor Freight with a coupon for about $11.00. Look around for a tool importer if there is no handy Harbor Freight.

You looked at images of fossil mammal jaws at calphoto.com?? Where exactly on that site are the fossils? Give us some directions to help navigate the site.

What did you find out about the stratum from which you took the jaw? Do you have a faunal list that includes a tapir? Which tapir (the scientific name)? (I couldn't find one in my books that listed anything but a Protapirus from the top member of the John Day Formation which is Early Miocene, not Late.)

You can guess at the identity of your jaw all you like. If you want guesses, you can get 'em here! If you want evidence to support a guess, you're gonna' have to do the work.

Good hunting!

[Straus]

First of all let me apologize for the incorrect reference to calphoto.com. I should know better than trying to write an address by memory. The correct site address is calphotos.berkeley.edu/ . I had the best luck using the drop down menus with as little input as possible. Eventually I just put in vertebrate fossils and oregon, which gave me a huge number of photos to look at.

As for responding to the rest of your questions, I found the jaw on a bed of gravel on the Oregon coast. It was in the Empire Formation which is late Miocene. Unfortunately, virtually all fossil mammal representation in this area has been marine mammals. There were two kinds of Tapirs in Oregon, Protapirus, as you mentioned and Tapirus. There was a tapirus tooth found on the southern oregon coast in 1914, but the formation was late Pliocene/ early Pliestocene. I didn't find references to any tapir fossils of the late Miocene, but I did read that there was an abundant growth in population for grazers after the forest lands turned into grasslands during the Miocene epoch. Tapirs were specifically listed, so although I am all too familiar with what the word "assume" means, I am making some assumptions here.

It is all the more challenging because I seem to have found a fossil where it does not belong. If I learn any new info (eventually going to go look at the university collection) I'll let you know.

[siteseer]

Straus,

On your behalf I will get the "in case of a need for a mammal expert, break glass" hammer and break the glass. I have a friend who's pretty good at identifying mammal bones even if they lack most diagnostic features. In the field he picks up every half-tooth and bone end so he has experience with less-than-great specimens to work with. He's also armed with quite a personal library and memory. I have tried to stump him a few times but his record is perfect so far. Since we don't have the correct answer already, this one won't count but he will have something to say. He's "old school" so I can't email him - will have to print out your photos and mail them to him via USPS so it might be a few days before I hear back. As with Harry, he will consider it interesting.

Jess

[Auspex]

...I found the jaw on a bed of gravel on the Oregon coast. It was in the Empire Formation which is late Miocene...

This opens a wider scope of investigation. When a fossil is not dug out of it's layer of interment, but erodes out from who-knows-where, it is called "float", and cannot be safely assigned to a particular stratum. This could be from the Pleistocene (or any other age in which deposition occurred there).

[Straus]

Siteseer, thanks so much. Auspex, I've been wondering about that. Although the crowns are sheared off, the broken edges are fairly sharp so it couldn't have been tumbling for too long. My husband found a mammoth tooth on the Willamette River about 15 years ago. It was well rounded! I have tried to find information on the net about whether or not the teeth being agatized is meaningful in terms of age or placement. I haven't found pertinent info yet, but I'll keep pecking away at it. Thanks for all of the input everyone! It's been a great learning experience so far.

[TourmalineGuy]

Straus,

Since you know what river, you can likely look up the watershed for that river. Comparing that to a geologic map you might be able to narrow it down pretty well. From what I know about that areas geology there is still a good chance it came out of the Empire, but a good chance isn't 100%, unfortunately.

Roddy

[Straus]

OOps! I screwed up what I was trying to say there! The UFO (unknown fossil object) wasn't in or near a river. It was at the bottom of a cut bank in an area of the Empire that is thought to be a marine conglomerate filled, wave cut channel. Some of the fossils suggest it was a protected, quiet water, like a bay. It was designated lower, upper miocene in 1976. The tooth that was on a river was the mammoth tooth that my husband found. Thank goodness they are relatively easy to identify! (Although in truth he picked it up on an agate hunting trip just because he thought it was a very cool rock! That was when the fossil bug started to bite) I will look at a geological map of the area though. That's a good idea.

[Harry Pristis]

OOps! I screwed up what I was trying to say there! The UFO (unknown fossil object) wasn't in or near a river. It was at the bottom of a cut bank in an area of the Empire that is thought to be a marine conglomerate filled, wave cut channel. Some of the fossils suggest it was a protected, quiet water, like a bay. It was designated lower, upper miocene in 1976. The tooth that was on a river was the mammoth tooth that my husband found. Thank goodness they are relatively easy to identify! (Although in truth he picked it up on an agate hunting trip just because he thought it was a very cool rock! That was when the fossil bug started to bite) I will look at a geological map of the area though. That's a good idea.

You've picked up some of the jargon, so you must be reading something geological or paleontological. Pay careful attention to the bibliographies in these papers (and the synonomies, if species are presented). If you can't access on the Internet some papers from these sources, request them from your local public library. You are looking for a faunal list with large mammals from the Empire Fm.

The bone still has a chunk of adherent matrix (which originally I mis-interpreted as part of a maxilla). I don't think it travelled too far as float. If another formation is exposed in the area, that would complicate matters.

[Straus]

See Harry, I listened to your advice!

[Harry Pristis]

See Harry, I listened to your advice!

You can't go too far wrong by listening to my advice, 'Straus'!

[Boesse]

To my knowledge, the only mammals reported thus far from the Empire Formation include the walruses Pontolis magnus, and Imagotaria sp., by Demere (1994). NARG collected a primitive balaenopterid skull from there a couple years ago. I'm sure that the Emlong Collection at the USNM has a bit of undescribed Empire Fm. material as well.

[Straus]

Wow! Thank you for the tip on the Emlong collection. I'm going to have a ball looking further into that tomorrow!

[Beatty]

I didn't think Boesse was trying to suggest any questions of "authority", and I didn't think Guest_Smilodon was suggesting that either. I think it was just that I rarely get on this forum and Boesse was trying to help by pointing you in the right direction for some answers I was not providing.

I am the last person to claim authority on anything, as I am a firm believer in the value of facts and evidence, and all too often people use their "authority" to make claims that are unsubstantiated or push their opinion despite the overwhelming evidence against their opinions. That said, I guess I do have experience with desmostylians and should just shut up and answer the question....

Desmostylian finds are uncommon generally, except for the masses of loose teeth from Sharktooth Hill in SoCal. Most are isolated fragmentary molars, and I don't think one could easily place how frequent mandible/maxillary fragments are found as a percentage, considering that few incidences of loose teeth are reported in the literature past the initial discovery of them in the 19th C and then the occasional report in Japan. If I were forced to report a rate of recovering jaw fragments with teeth, I would probably aim it at 10-20% of finds (with Sharktooth Hill be excepted from this estimate), and that is only because so few specimens make it to collections where they can be studied unless they are more complete. Also, it probably doesn't hurt the chances of decent preservation that these critters seem to have lived during a particularly volcanically active time of the Pacific rim, so many are deposited in ashes that preserve very, very well (although a pain to CT because ashes are fairly radio-opaque).

Does that answer your question, Smilodon? I'm sorry to be long-winded, but that's my nature. I hope no misunderstanding persists among anyone here, this is too interesting, open, and friendly a forum to let these sorts of things spoil it.

Brian

[Beatty]

Yes, the Emlong Coll and Condon Coll (Univ OR in Eugene) has a bunch of interesting Empire Fm material. If anyone is getting work done on those, I have loads of pics and measurements of specimens of many of these specimens, and would love to collaborate to get them done sooner. There is simply not enough lifespan to get all the research done, and collaborating can make things go more quickly. In the immortal words of Samwise Gamgee, "Share the load"

Beatty

[Straus]

Before I say anything else I want to say that any misunderstandings that happened during this forum were completely cleared up in a friendly and helpful manner. That being said, thanks for the camel pics.

I still think that the closest match that I could find is tapir. The jaw structure seems very close... the teeth are not too helpful since crowns are gone. I need to get to the U of O collection and look at the samples there. The biggest problem is that it just doesn't seem to belong in the Empire. Will look at more photos of the camel teeth in calphoto, Berkley. I will try to post any of those and the tapir photos I find later today. Once again... thanks everyone!

[Straus]

Here are a couple of the tapir photos I was looking at. The thing is... even with the crowns sheared off, the bottoms of the teeth seem very square, and the roots are not real deep. When I was looking at examples before, I felt like the camel teeth and roots were the wrong shape and depth. These two photos (and subsequent research, such as a tapir bone from a later era being found on the Oregon coast) were what made me wonder about it being tapir. Granted, the first photo shows a mandible from a much larger animal.

[MOROPUS]

Caaaaaalm down, boys! Have a drink; walk a little...

As I said, an old horse!

[Straus]

I looked at horse teeth as well but they seem the wrong shape to me. While some of them have the squared look of my fossil they seem to have more or different roots.

I'm attaching some photos.