digit Posted May 31, 2015 Posted May 31, 2015 I collected some micro-matrix gravel while hunting a site in the Peace River that had a good abundance of mammal fossils. My hope was that there would be some micro mammal fossils as well. I seemed to have guessed correctly as I turned up this nano molar which I assume is rodent based the size (~1.7 mm diameter across the occlusal surface x 2.7 maximum height to the end of the one remaining root). I tried to get a clear image of the occlusal surface but believe me something this small is hard to hold and keep in the focal plane. Would be interesting to see if Rich or any of the others who might know their tiny mammals can make an ID on this little speck of a fossil. -Ken
RichW9090 Posted May 31, 2015 Posted May 31, 2015 Rodents aren't my forte, but it looks like a Neotoma M2. Neotoma floridana is common in the Pleistocene of Florida. The plural of "anecdote" is not "evidence".
digit Posted May 31, 2015 Author Posted May 31, 2015 Thanks for the reply. I'll follow that line of investigation. A quick search of available images for that species online haven't turned up anything that seems to match exactly but given that this tooth is a bit worn down and devilishly hard to photograph I may have to use some imagination to match-up the various ridges. Cheers. -Ken
gturner333 Posted May 31, 2015 Posted May 31, 2015 it may also be a Sigmodon sp. (cotton rat). Their tooth pattern also looks similar to this.
Harry Pristis Posted May 31, 2015 Posted May 31, 2015 I think Sigmodon m2 is a good guess. http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest
RichW9090 Posted June 1, 2015 Posted June 1, 2015 Yeah, Gturner333, that is the other possibility - two closely related sigmodontines. Size isn't going to help much here, as it is in the upper range of Sigmodon species and the lower range of Neotoma species. The plural of "anecdote" is not "evidence".
digit Posted June 1, 2015 Author Posted June 1, 2015 Thanks guys. I love finding novel fossils so that I can use that as a prompt to go explore a line of research in more depth. This should be fun to go investigate. Cheers. -Ken
Diceros Posted June 1, 2015 Posted June 1, 2015 Rich - The little rodent molar has the "S" occlusal pattern that stands for Sigmodon ("sigmoid tooth"); and, of course, Superman. Digit - Nice pics, not easy to take.
digit Posted June 1, 2015 Author Posted June 1, 2015 Thanks. I used my little digital microscope (basically a webcam on a stand with a ring of LEDs around the lens for lighting. It has a closer minimum focus distance and more magnification than the macro capabilities of my point and shoot (need to break down and spend some money on a nice macro lens for my main DSLR). The big problem with photographic 2mm subjects is the razor thin (in a quite literal sense) depth of field.The only way to hold this sesame seed size fossil to show the occlusal surface was pinched between my fingers--not the most stable platform for photography. I've got a fair bit of micro-matrix from a few locations in South Florida cached in my garage (do people use garages for other purposes than holding fossils?) and I'm hoping it lasts me through the summer when the rivers/creeks are restocking with fossils. As I get more into micros (hopefully finding some more photo worthy candidates) I'm going to need to explore better photo setups. I'll go see who is taking the best micro photos online (several people take stellar images) and I'll pick their brains. I'm quite chuffed at finding this little "super" fossil. Sometimes extremely small fossils can be as much fun as extremely large ones. I do see the subtle humor in finding both a Mammuthus and Sigmodon in the same month from the same site. Thanks all for the help and the opportunity for learning. Cheers. -Ken
Khyssa Posted June 1, 2015 Posted June 1, 2015 Finding small fossils can be quite fun, particularly since I've found that they tend to be small enough that they don't get as beat up as the larger ones. This past weekend I was going through some matrix that I had collected from the Peace and found a snake vert that's about the size of your tooth. I'm having a similar issue with trying to photograph them. Someone showed me a link to a phone attachment that allows you to take micro pictures but it was for an iphone and I have an android. Haven't looked yet to see if something similar is available for my phone.
digit Posted June 1, 2015 Author Posted June 1, 2015 And the good thing about micro-fossil hunting is that you can do it sitting in a comfortable chair (and with a glass of fine sipping rum at arm's length as I had when I found this little one). Not wanting to jeopardize my "dinosaur" status I've never had to make the iPhone/Android decision. I use a cheap flip-phone that does one thing--make calls. No texting, no photos, no minute-by-minute compulsive Facebook updating or email checking. It rings when I have a call and sits in my pocket otherwise. I have enough gray hair atop my head that I can be consciously Luddite and get away with it. Cheers. -Ken
Khyssa Posted June 1, 2015 Posted June 1, 2015 Yes, searching in a comfy chair in the A/C is one of the wonderful things about micro-fossil hunting! Although it is a bit of a distraction when I should be doing house work. I was firmly against getting a smartphone until I started trying to sell garden art at farmers markets. It became apparent to me fairly quickly that I needed to get one of those square card readers as few people carry check books or much cash these days. After I got the smartphone I also discovered it is very useful for looking up directions, researching things when I'm at a store or out in nature, taking pictures, and keeping me entertained when stuck in a doctors waiting room. Rarely do I use it for e-mail or facebook.
gturner333 Posted June 1, 2015 Posted June 1, 2015 As for your depth of field problem, there are "stacking" programs that help. I use Zerene Stacker, which works well. But, you do need to be able to take multiple photos that are focused slightly differently. There may be some inexpensive USB microscopes available now.
digit Posted June 1, 2015 Author Posted June 1, 2015 I've seen the impressive results of nano-micro-macro-photos of tiny bugs and things where the focus was panned slightly while shooting a series of photos and then they were "stacked" to produce an astounding image with unimaginable depth of field. I've always loved macro photos and that technology will likely soon pull me in to getting back to shooting tiny little things with an entirely new look. I've had fun using HDR software to create images with High Dynamic Ranges which can also produce some interesting photos. Would likely be tough to even get a series of photos of this little tooth that were stackable. What I'd probably need is a small glob of putty/clay or maybe that tacky stuff kids use to put in the corners when hanging posters in their rooms these days. If I could set the tooth upright into some "artificial gums" then I could likely micro-manipulate the height of the USB "microscope" and shoot a series of photos to be stacked. What I may end up doing instead is getting a nice macro lens for my DSLR and a few magnifying diopters to increase the magnification. I can then flood it with light and shoot at a really tiny f-stop (like f/32 or f/45) to maximize the DOF in a single image. It's probably best that I'm busy with a huge amount of copy editing work at the moment or I'd likely be online spending thousands of dollars on optics to photograph sesame seed size fossils. I do see "stacking" software in my future though.... Cheers. -Ken
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