Auspex Posted November 1, 2010 Share Posted November 1, 2010 I just added two interesting track plates to my display collection; both are from the Green River Formation (Eocene), and both involve bird tracks. The first one that I'd like to show is a positive (top-cast) that contains well-defined multiples of two different size bird tracks; the one-inch un-webbed "shorebird" tracks that are so typical of the Green River Fm's lake shores, and some much more delicate 3/4" tracks. These tiny tracks are smaller than I have never seen or heard of before. Both types of tracks are arranged with a walking gait (as opposed to hopping), as is typical of all the Eocene bird tracks with which I am familiar. This little guy was a very small bird; the feet of the modern House Sparrow are larger! The second plate has a lot going on. It is a negative (bottom), and was made in a slightly "soupy" layer of silt; you can see where the bird's feet sunk into the surface more (these are the typical 1" un-webbed type). Here is the fun stuff: there are multiple wiggly trackways made by nematodes, many straighter "worm" tracks, a dessication crack, and wall-to-wall (somewhat washed out) rain drop impressions. A curious feature of the "worm" tracks is that they are all going the same general direction, and along the continuing course of several of them are small raindrop-like pits, better defined and thus more recent than all the raindrops. These tiny "craters" occur only on the "worm" tracks, so I doubt they could be droplets. Real puzzlers! I have to confess, I love Ichnos. If I ever find myself in a position to expand the scope of my collecting, I would take on trackways (and then, busy hash plates) "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...
Roz Posted November 1, 2010 Share Posted November 1, 2010 Wow, most cool.. I really like that second plate that has all kinds of things going on.. Very nice plates! Welcome to the forum! Link to comment Share on other sites More sharing options...
Ordovician_Odyssey Posted November 1, 2010 Share Posted November 1, 2010 (edited) wow, there both amazing! but the second is "extra ordinary" great peices to add to a collection! Edited November 1, 2010 by trilobite guy -Shamus The Ordovician enthusiast. Link to comment Share on other sites More sharing options...
tracer Posted November 1, 2010 Share Posted November 1, 2010 i paid a guy ten bucks to tell me something intelligent to say about these plates and he took my money and left and now won't answer his cellphone. dang it. but i'm happy when you're happy, even if it's cuz you got footprints of underground brids standing upside down under the earth. gotta be rare i'm thinkin'. Link to comment Share on other sites More sharing options...
Terry Dactyll Posted November 2, 2010 Share Posted November 2, 2010 Auspex.... Initially the top plate grabbed my attention, its very nice and I can see why you love it but when you enlarge that bottom plate wow, the preservation, it could be from yesterday Fantastic aquisitions... Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
flyguy784 Posted November 2, 2010 Share Posted November 2, 2010 "These tiny "craters" occur only on the "worm" tracks, so I doubt they could be droplets. Real puzzlers!" Almost looks like the little worm like creatures were occaisionaly pressing their "faces" or "rear ends" into the surface. Possibly feeding activity or searching for a optimum burrowing location. I'd think you could lend credance to this idea if there was a way to measure the radius of the "track" and compare it to the circumference of the "crater". That shouldn't be too tuff considering the high degree of detail in the preservation. Link to comment Share on other sites More sharing options...
alopias Posted November 2, 2010 Share Posted November 2, 2010 great tracks plates Link to comment Share on other sites More sharing options...
glacialerratic Posted November 2, 2010 Share Posted November 2, 2010 Super nice, Auspex! Gottta love that Green River Shale... Link to comment Share on other sites More sharing options...
Auspex Posted November 2, 2010 Author Share Posted November 2, 2010 "These tiny "craters" occur only on the "worm" tracks, so I doubt they could be droplets. Real puzzlers!" Almost looks like the little worm like creatures were occaisionaly pressing their "faces" or "rear ends" into the surface. Possibly feeding activity or searching for a optimum burrowing location. Since they are associated with whatever made the tracks, it seems logical that they might have been made by the track makers. I just can't visualize how they could have created the "craters" and then not deform them as they moved on. "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...
ebrocklds Posted November 2, 2010 Share Posted November 2, 2010 (edited) auspex, can't be sure but i think your fist plate also has the webbed track of presbyornis in the top right corner. see image. the second plate is fantastic, most nematode tracks are not very clear but those are very easy to see. to me the "worm tracks" appear to be weathering as i have seen it several times before wile digging and the lines are always parallel and are parallel with the face of the hill. although the craters on yours make it seem more plausible?? great specimens in any case. Brock Edited November 2, 2010 by ebrocklds Link to comment Share on other sites More sharing options...
MikeD Posted November 2, 2010 Share Posted November 2, 2010 Those are cool. Link to comment Share on other sites More sharing options...
Auspex Posted November 2, 2010 Author Share Posted November 2, 2010 ...can't be sure but i think your fist plate also has the webbed track of presbyornis in the top right corner... If that is a track, it was made (and weathered) before this layer of silt was deposited. Something caused the deformation, but the features are so indistinct that I don't have enough confidence to call it. ...to me the "worm tracks" appear to be weathering as i have seen it several times before wile digging and the lines are always parallel and are parallel with the face of the hill. I just put a loupe on these with this idea in mind, and there are features too hard to describe adequately; gonna' try my luck with microphotography. Be back in a bit! "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...
Auspex Posted November 2, 2010 Author Share Posted November 2, 2010 Well, that was frustrating; my digital microscope has a ring of LEDs around the lens that cannot be turned off, and side-lighting is the only way to see the details . Using the LEDs as a side-light, and taking the pics with my camera through a low-power loupe, I was able (sort of) to illustrate some larger features of interest (the pin is a large one, from a Reiker case): Most of the parallel "tracks" do look to be the result of moving water, occurring after the rain drops but before the various tracks. There are a couple meandering, more wormlike trails that go against the flow, and I found an arthropod trackway . I think now that the "craters" were made by air bubbles escaping where a rivulet of water thinned the surface just enough to let it pop. The dessication crack is evidence that the whole dried out enough before being inundated to resist erosion of the finer details. This whole plate, by the way, is 3/16" thick, and appears to be a single "varve" with a wash of silt on top. "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...
tracer Posted November 2, 2010 Share Posted November 2, 2010 don't know, man...still seems like the ichno stuff is dicey to me. i'd hate to think that nematodes are getting the blame for trails caused by biting midges more folks just need to stumble through life unsure of everything like i do. i think... Link to comment Share on other sites More sharing options...
Terry Dactyll Posted November 2, 2010 Share Posted November 2, 2010 (edited) Auspex... I agree with the mud bubbles idea.... it makes sense....and explains the randomness....I think these ones possibly represent the 'counterpart'.... Edited November 2, 2010 by Terry Dactyll Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
Auspex Posted November 2, 2010 Author Share Posted November 2, 2010 Nematode trails, then as now: My link "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...
tracer Posted November 2, 2010 Share Posted November 2, 2010 that was like one of the weirdest links i've ever clicked on, which is saying something. but still, just cause somebody can gyrate don't make them snoopy, if you know what i mean, and i know you do know what i mean, cuz of that vulturecan mind-meld thing we got goin' on... Link to comment Share on other sites More sharing options...
Auspex Posted November 2, 2010 Author Share Posted November 2, 2010 Ichnofossils are described and named via the same process as actual critters. They are "form species" though; most of the time, the maker is unknown (rarely are a critter's remains found at the end of its tracks). If midge larvae and nematodes leave the same marks, there is no way to differentiate the makers. The squiggly trails on the plate in question should probably be called "Cochlichnus", which is the ichnogenus name given to that form (not that exact form, but the general form; they are further differentiated by appending the ichnospecies name and the author of the paper written about the version closest to the one in question: NONE OF WHICH HAS ANYTHING TO DO WITH THE MAKER OF THE TRACE!). Ichnofossils are discomfiting to many because they are not an organism, they are a record of an (often) unknown organism's activities. On the bright side, they are clues to behavior, and to the paleoenvironment. Good ichno work can determine that a particular assemblage might represent (for example) a low-energy, low-saline estuary with an average depth of six meters. This is a type of paleoecology that cannot always be done with "real" fossils. I like 'em "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...
tracer Posted November 2, 2010 Share Posted November 2, 2010 soooo...when taxonomic classification fails, the great thing about ichnos is that you can punt to seilacherian, toponomic, or some other "groupthink" methodology of labeling them after you've rorschached them out of the inconsequentiality of randomness. love you man...and love your squiggles. p.s. - watch how you display them in your abode - keep the feng shui righteous. Link to comment Share on other sites More sharing options...
Scylla Posted November 2, 2010 Share Posted November 2, 2010 Since they are associated with whatever made the tracks, it seems logical that they might have been made by the track makers. I just can't visualize how they could have created the "craters" and then not deform them as they moved on. Because they made the marks with the back end of the worm. Do worms ever pee? Link to comment Share on other sites More sharing options...
tracer Posted November 2, 2010 Share Posted November 2, 2010 Because they made the marks with the back end of the worm. Do worms ever pee? UROLITES!!! Link to comment Share on other sites More sharing options...
dhk Posted November 6, 2010 Share Posted November 6, 2010 Love the plates and you know I love the Ichnos. Sometimes it's the grouping methodology is all we have with ichnos. When you stop to think about the shere number of species wondering around, endless behavioral patterns involved, the lack of bodies and the ultimate distortions inherant in the prosess sometimes we just can not hone in on a specific species with these. But that being said... I'm sure those avians got a great meal with the worms and concider this... the "raindrop" impressions might just be feeding marks created by beaks pecking into the sediment. they would cause a impact crator similar to a raindrop impact after the worm was pulled out and the sediment fell back into place. Just a thought. Anyway, wonderfull ichno plates that tell a great story. Darin Link to comment Share on other sites More sharing options...
bear-dog Posted November 6, 2010 Share Posted November 6, 2010 (edited) Yes but not as often.If they didn't they would splode.It is pretty hard for them to use the urinal. Ok ,ok ,just kidding.It is done in the same process when they poop.Sorry about the smart aleck answer,tracer is rubbing off on me. Edited November 6, 2010 by bear-dog Bear-dog. Link to comment Share on other sites More sharing options...
bear-dog Posted November 6, 2010 Share Posted November 6, 2010 i paid a guy ten bucks to tell me something intelligent to say about these plates and he took my money and left and now won't answer his cellphone. dang it. but i'm happy when you're happy, even if it's cuz you got footprints of underground brids standing upside down under the earth. gotta be rare i'm thinkin'. :lol: Nuff said. Bear-dog. Link to comment Share on other sites More sharing options...
TheFossilHunter Posted November 7, 2010 Share Posted November 7, 2010 Hey Auspex, May I ask how much these plates cost you? Thanks Mike P.S> Great plates by the way:) Link to comment Share on other sites More sharing options...
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