Pilobolus Posted June 25, 2017 Share Posted June 25, 2017 Hey all... went to the "world famous" Windmill site (RIO PUERCO, New Mexico, Cretaceous, Turonian) to try and excite two budding fossickers yesterday, found a couple of interesting shells...the larger bivalve I've only collected once before, the limpet-looking oddity, never before...any ideas? Reverse....(not present, but hey, look at that photo cube that arrived this week!) Link to comment Share on other sites More sharing options...
Pilobolus Posted June 25, 2017 Author Share Posted June 25, 2017 And the limpet-like thingamajig... Link to comment Share on other sites More sharing options...
Pilobolus Posted June 25, 2017 Author Share Posted June 25, 2017 Reverse (etc) clip from text as I could not resize on the phone.... Oh... those two images show the same side....sorry so fuzzy.... Link to comment Share on other sites More sharing options...
Al Dente Posted June 25, 2017 Share Posted June 25, 2017 The limpit like object could be the sediment from between two shark or fish vertebral centra. 3 Link to comment Share on other sites More sharing options...
Pilobolus Posted June 25, 2017 Author Share Posted June 25, 2017 5 minutes ago, Al Dente said: The limpit like object could be the sediment from between two shark or fish vertebral centra. Well, that's a most interesting take! Link to comment Share on other sites More sharing options...
Peat Burns Posted June 25, 2017 Share Posted June 25, 2017 I agree with al dente regarding the identity of the 2nd item. Link to comment Share on other sites More sharing options...
Wrangellian Posted June 25, 2017 Share Posted June 25, 2017 I see Aerogrower has made another 2cm cube! Mine was the first. That bivalve looks like Pholadomya to me. 2 Link to comment Share on other sites More sharing options...
abyssunder Posted June 25, 2017 Share Posted June 25, 2017 Could you, please, take a shoot of the specimen like in picture 5, but without your fingers? I'm curious if the pointing ends of the two parts are alligned to the same axis or to parallel axes. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Pilobolus Posted June 25, 2017 Author Share Posted June 25, 2017 Will do, and apologies for the interference of the ugly tactile digits Link to comment Share on other sites More sharing options...
Pilobolus Posted June 26, 2017 Author Share Posted June 26, 2017 Link to comment Share on other sites More sharing options...
sagacious Posted June 26, 2017 Share Posted June 26, 2017 I agree with Al Dente -- it's a sediment 'cast' of the space between two bony fish or shark vertebral centra. Occasionally I find the shallow-conical sediment cast from a single side of one centrum, and that as well often looks very much like a limpet shell fossil. Link to comment Share on other sites More sharing options...
westcoast Posted June 26, 2017 Share Posted June 26, 2017 Interesting from @Al Dente and @Sagacious. Do you guys have any images of these intervertebral sediment fills? What is the off-white shell- like material on the outside and why are the two cones not aligned? Link to comment Share on other sites More sharing options...
Mike from North Queensland Posted June 26, 2017 Share Posted June 26, 2017 Westcost the off-white / shell - like material is actually the surface / part of the fossil vertebrae that are 99.99 % missing in the shown specimen. the alignment is due to the vertebrae no longer in perfect alignment, below are some examples where the fossil has moved, but in these I have cleaned away most of the infill where there were no adjoining vertebra. Imagine the infill between these shark verts. Mike D 3 Link to comment Share on other sites More sharing options...
westcoast Posted June 26, 2017 Share Posted June 26, 2017 29 minutes ago, Mike from North Queensland said: Westcost the off-white / shell - like material is actually the surface / part of the fossil vertebrae that are 99.99 % missing in the shown specimen. the alignment is due to the vertebrae no longer in perfect alignment, below are some examples where the fossil has moved, but in these I have cleaned away most of the infill where there were no adjoining vertebra. Imagine the infill between these shark verts. Mike D Thanks Mike for the clear explanation. That does it for me. Haven't come across that before. Link to comment Share on other sites More sharing options...
Pilobolus Posted June 26, 2017 Author Share Posted June 26, 2017 20 hours ago, Al Dente said: The limpit like object could be the sediment from between two shark or fish vertebral centra. Thanks Al Dente! I have to say that this interpretation looks highly supported and is even more exciting for me than the limpet theory. I knew limpets were not bilaterally symmetric, so I worked up a theory that a terrible mud storm had caught two in flagrante delicto. I also fantasized that these were specimens of a heretofore unreported species that I would name Lottia cabezoni... Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 26, 2017 Share Posted June 26, 2017 I agree with Pholadomyia for the first specimen, and an impression from between two fish vertebrae for the second. Pretty sure limpets do not copulate like that. Don 1 Link to comment Share on other sites More sharing options...
Pilobolus Posted June 26, 2017 Author Share Posted June 26, 2017 8 hours ago, Mike from North Queensland said: Westcost the off-white / shell - like material is actually the surface / part of the fossil vertebrae that are 99.99 % missing in the shown specimen. the alignment is due to the vertebrae no longer in perfect alignment, below are some examples where the fossil has moved, but in these I have cleaned away most of the infill where there were no adjoining vertebra. Imagine the infill between these shark verts. Mike D Of interest, the white patina (0.01% vert) stuck to my tongue whilst the mud color did not...would this be an indicator of bony fish over cartilaginous shark? Link to comment Share on other sites More sharing options...
sagacious Posted June 26, 2017 Share Posted June 26, 2017 15 hours ago, westcoast said: Interesting from @Al Dente and @Sagacious. Do you guys have any images of these intervertebral sediment fills? What is the off-white shell- like material on the outside and why are the two cones not aligned? I wish I had one I could show a photo of, just for comparative and general educational purposes, but I don't keep the ones I find. I just don't have the space for everything I find. Mike D is spot-on with his explanation of the 'shell-like material' and off-alignment. I found a very nicely preserved one of these single-side centrum-casts a few weeks back that looked so much like a fossil limpet shell that I had to study it closely for a minute to be sure it wasn't. They can really look convincingly shell-like. The 'tongue test' pretty much only 'tests' for residual porous calcium carbonate, which in this case isn't a discriminator between bony fish and shark. Some research on your formation's fauna might turn up some suspects. Link to comment Share on other sites More sharing options...
abyssunder Posted June 26, 2017 Share Posted June 26, 2017 Thank you for the picture, Pilobolus. Are the pointed ends in the middle of the cones or not, also, have the two cones the same diameter at the base? " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Pilobolus Posted June 26, 2017 Author Share Posted June 26, 2017 I'll scare up the calipers... Link to comment Share on other sites More sharing options...
Pilobolus Posted June 27, 2017 Author Share Posted June 27, 2017 16 hours ago, abyssunder said: Thank you for the picture, Pilobolus. Are the pointed ends in the middle of the cones or not, also, have the two cones the same diameter at the base? Good morning abyssunder: It would appear that the points are in the middle of the cones, but it is also evident that there is uneven weathering around the outside edge. The little tab of material looks to be further disk material. Assuming the I.D. is correct, which I am (sediment infilling between verts), the verts themselves were slightly offset from one-another, depending on what side angle one chooses to view, which is not unexpected from death and decay. Alternative fantasy explanation is that this fish was murdered by hanging or other neck popping trauma. Link to comment Share on other sites More sharing options...
PFOOLEY Posted June 28, 2017 Share Posted June 28, 2017 I was out there yesterday and I saw some guy hauling away a shark skeleton on a flatbed...he looked very pleased with himself. "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...
Pilobolus Posted June 28, 2017 Author Share Posted June 28, 2017 Good grief...are you pulling my leg? Link to comment Share on other sites More sharing options...
PFOOLEY Posted June 28, 2017 Share Posted June 28, 2017 5 minutes ago, Pilobolus said: Good grief...are you pulling my leg? Nope. I caught up with him on 550 as I thought it might be you... Photo: Christoph Schmidt, AFP/Getty Images 1 "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...
Pilobolus Posted June 28, 2017 Author Share Posted June 28, 2017 Link to comment Share on other sites More sharing options...
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