jpc Posted December 15, 2014 Share Posted December 15, 2014 (edited) Last week it was fall. Today it is winter. We have 8 to 10 inches of the white stuff all over the place. But last weekend the GF and I went fossiling west of town to one of my Eocene mammal sites. Our time was limited so I only got a few surface finds, but I scraped the surfaces of two anthills and scored very well. Each one offered about 30 little teeth. That's 30 complete teeth...maybe 4 times as many broken teeth and twice as many shark teeth. This is my first series of pix from that outing. More to follow, I hope. All these pictures are shot through the microscope. The teeth are measured in millimeters. To find these I pour a small sample onto an index card and scout the whole lot under the microscope. Here is a tooth as discovered. We are actually looking at the root side; the roots are missing. In the second photo I have rolled it over and we are looking at the chewing surface. This one has a lot of dirt on it. And here is a stereophoto of the same tooth after a quick sandblasting (bicarb at 40 psi, for those who need to know). Lots of stereophotos coming up. If you can't see stereophotos, feel free to just look at half of each set. If the pix are too big when you click on them you can make them smaller and more stereovier friendly with a simple "ctrl -" or two... at least on non-Mac products. Lower molars tend to be more common than uppers. I think this is because they are more robust. So here is a flock of lower molars. These things are rather tough to ID. All the info you need is scattered in countless scientific papers. There is no field guide. And lowers tend to be less variable, therefore more difficult top ID than uppers. The middle one in the column of three is probably a rodent. The two lower teeth are m3's... third (and last) molar in the lower jaw. This next photo shows three upper molars. The two on the bottom are very similar with a difference in size, and the top one is quite different. (Change of plans... that photo will start the next post). Edited December 15, 2014 by jpc Link to comment Share on other sites More sharing options...
jpc Posted December 15, 2014 Author Share Posted December 15, 2014 (edited) And another couple of upper molars..I think they are M3.. last upper molar. Very similar, again with a slight size difference, and more wear on the bigger one. These are probably from two species of very similar beasts. This next set is three small premolars. They are 4th upper premolar from a condylarth called Hyopsodus. Notice how they all look the same. The next three are premolars from two different mammals. The larger top one is from a carnivore. There is a visible carnassial notch at the left base of the large cusp. Hard to see in this photo, but trust me. The bottom two are very similar except from different sides, so I think they are from one species...not sure what. This one is a single incisor and lastly three different icisors... not in steroe. Top to bottom, rodent, primate and multituberculate. And this one it most interesting. This is a fragment of tyrannosaur tooth. But you say... this is an Eocene site. Yes it is. But there are some strange things here. I have few other theropod teeth form here and some baculite pieces and the aforementioned shark teeth. Wyoming's Eocene is very well known, and there were no sharks here in the Eocene... the ocean had retreated a while ago. There are indeed stingrays, but that is a different story (and this site does have numerous ray teeth). I think this site features a lot of reworked fossils. So, an Eocene river was flowing through here and cutting away at the riverbanks, which were cut through older rocks full of fossils, esp shark teeth. The stuff all gets deposited in a pool or something all mixed up together. Eocene mammals, Cretaceous dino bits and sharks and baculite pieces. In this area, all three of those faunas (sharks, dinos and baculites) are found in different formations. When I do get down to IDing all these teeth, I would be willing to bet some of them will be Paleocene species. But that is another project. Edited December 15, 2014 by jpc Link to comment Share on other sites More sharing options...
Auspex Posted December 15, 2014 Share Posted December 15, 2014 Coolest. Microteeth. Ever. Seriously! I gotta wonder, with the reworking, whether any are Cretaceous mammal??? "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 15, 2014 Share Posted December 15, 2014 Wow! The stereo photos are quite nice. Looking forward to the remaining specimens. It will be interesting to see your deciphering the age. These are very cool...but I won't quite say "ever" just yet ...there are more to see! "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
jpc Posted December 15, 2014 Author Share Posted December 15, 2014 auspex... I have seen a lot of Cretaceous mammals in my Lance and Hell Creek outings and pickings, and very few if any of these guys seem Cretaceous... for certain. I do a have a beautiful multituberculate molar from this site (collected a few years ago) that I have yet to ID, but it could be Cretaceous. Multis were common in the Cret but rare in the early Eocene (Wasatchian) which I suspect is what this site really is. pfooley... more pix will come, but I need to work on the fossils a bit still. And maybe dig out some older finds. By the way... the background on these pix is sand from the Flaming Cliffs of Mongolia. Link to comment Share on other sites More sharing options...
jpc Posted December 16, 2014 Author Share Posted December 16, 2014 (edited) A few more form last weekend's outing. First a piece of lizard maxilla and a piece of theropod tooth. and one larger tooth, an third upper molar of Hyracotherium, the dawn horse. It s missing an edge on the left side. This was not on the anthills, but just on the surface. And here are a bunch of shark teeth. Notice they are all incomplete. I have dozens from this site, and I don;t think a single one has a complete root. This is one reason I think the sharks are reworked from Cretaceous sediments. Also, there is no sign of Ptychodus among them. Ptychodus is fairly common in the Frontier Fm, which is Cenomainan/Turonian in age. There are also shark teeth in the Mesa Verde Fm, which is Campanian and as far as I know, lacks Ptychodus, so I think these are reworked out of the Mesda Verde Fm. Here are a few more that I dug out of my collection last night... from the same site, collected as far back as 1999. A couple more mammalian upper molars. The top one is the proto-rhino Hyracodon. I don't know what the bottom one is. This is one of my favorites... a Pachyaena molar. This is a mesonychid, which until recently were thought to be the ancestors of whales. Whether they are or not is for a different post... they are cool animals. You can really see the carnassial notch at the lower base of the main cusp on this guy. OK, if that one was one of my faves, this one tops the list. This is the only multituberculate molar I have pulled out of this site. Probably Ectypodus, for those keeping score. First upper molar. Edited December 16, 2014 by jpc Link to comment Share on other sites More sharing options...
jpc Posted December 16, 2014 Author Share Posted December 16, 2014 Oh, forgot this one, also collected many years ago... I did a little bit of quarrying, which proved successful. Plan to do more someday.... This came out of the quarry... a Viverravus jaw. A little miacid carnivore. Sorry the colors are lousy on this photo. And that concludes this little show of Eocene mammal teeth from Natrona County, Wyoming. Thanks for looking. Hope you enjoyed it. Link to comment Share on other sites More sharing options...
fossilized6s Posted December 16, 2014 Share Posted December 16, 2014 Superb finds sir! Love the info and pics. Such a wide variety. I love finding mammal teeth while micro hunting. ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
Auspex Posted December 16, 2014 Share Posted December 16, 2014 Your ant hills are legendary, JP! Done right, they just keep on giving "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
jpc Posted December 16, 2014 Author Share Posted December 16, 2014 yup.. I collected these last time about 5 years ago. Just collect the outer layer and the ants will collect me some more fossils. Yes, they are wonderfully rich. To find 30 little mammal teeth in one anthill, and in its neighbor, is nothing short of spectacular. Link to comment Share on other sites More sharing options...
Al Dente Posted December 17, 2014 Share Posted December 17, 2014 That multituberculate tooth is impressive. It's nice to be able to see it in 3-D. I would be interested in seeing pictures of the Eocene ray teeth. I've seen lots of photos of the Green River Fm. rays but have never seen their teeth. Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 17, 2014 Share Posted December 17, 2014 ...Hope you enjoyed it. I did. Thanks for sharing. "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
jpc Posted December 17, 2014 Author Share Posted December 17, 2014 That multituberculate tooth is impressive. It's nice to be able to see it in 3-D. I would be interested in seeing pictures of the Eocene ray teeth. I've seen lots of photos of the Green River Fm. rays but have never seen their teeth. I don't know if these are Heliobatis teeth or Myliobatis. If I get a chance i will try to take some pix of them and post them. Link to comment Share on other sites More sharing options...
siteseer Posted December 28, 2014 Share Posted December 28, 2014 Great stuff, JP. I think you mean Hyrachyus for the proto-rhino. I don't know what the bottom one is either. I think you said in another thread that there is no collector's guide for Eocene mammals like there is for sharks and shells. Wouldn't that be great? This stuff is at least two levels of weird from the Oligocene badlands material because many of the Early Eocene mammal groups died out before the Oligocene. Jess A couple more mammalian upper molars. The top one is the proto-rhino Hyracodon. I don't know what the bottom one is. hyracodon and .jpg Link to comment Share on other sites More sharing options...
siteseer Posted December 28, 2014 Share Posted December 28, 2014 JP, When I've looked at one of those beautifully complete Green River stingrays, I've assumed that the teeth must be less than a millimeter in any dimension or they fell out or they remain within the matrix because I haven't seen one. I have seen some isolated dasyatid-like teeth from the Wasatch Formation in Sweetwater County, Wyoming. They range from 1-3mm high and from that I assume that those rays must have been much larger than the "split fish" or 18-inch layer specimens (or they were just somewhat larger with unusually-large jaws and teeth?). Jess I don't know if these are Heliobatis teeth or Myliobatis. If I get a chance i will try to take some pix of them and post them. Link to comment Share on other sites More sharing options...
kauffy Posted December 28, 2014 Share Posted December 28, 2014 Not common at all, very cool stuff!! Thanks a lot for sharing. "Turn the fear of the unknown into the excitment of possibility!"We dont stop playing because we grow old, we grow old because we stop playing. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now