garyc Posted October 23, 2014 Share Posted October 23, 2014 This is a Brazos River pleistocene find. When I first saw it, I thought it was a horse astragalus. But the more I search, it is looking like a sloth knuckle to me. I am still not sure. Anyone? Link to comment Share on other sites More sharing options...
jpevahouse Posted October 23, 2014 Share Posted October 23, 2014 Looks more like a weathered horse astragalus. I believe a comparable sloth bone would be considerably larger than 4 inches. Right size for horse though. Link to comment Share on other sites More sharing options...
garyc Posted October 23, 2014 Author Share Posted October 23, 2014 (edited) That's what I thought at first. But, look at the bottom where it would articulate with a calcaneum. Here's a pic side by side with another horse astragalus. Edited October 23, 2014 by garyc Link to comment Share on other sites More sharing options...
Harry Pristis Posted October 23, 2014 Share Posted October 23, 2014 I'm not certain what you have there, Gary. Which sloth bone do you think it is? For comparison: http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
garyc Posted October 23, 2014 Author Share Posted October 23, 2014 I can't say for sure, Harry. I think it looks most like the bone 3rd row from the bottom, 2nd from the right in your drawings. It's hard to compare what I have in hand to 2 dimensional pics. I will add a few more pics of this bone with other horse astragali that I have to show why I really don't think this one is horse. Link to comment Share on other sites More sharing options...
garyc Posted October 23, 2014 Author Share Posted October 23, 2014 You can see how the base of the bone in question protrudes out to the right. There is some cancellous bone showing on the opposite side, so I think it would protrude to the left as well. The base of the horse astragali ends with the ridges. Also, the base of the bone in question seems pretty smooth and slightly concave; compared to the horse astragali which have flatter bases with grooves where they articulate with the calcaneum. Link to comment Share on other sites More sharing options...
Harry Pristis Posted October 23, 2014 Share Posted October 23, 2014 I can't say for sure, Harry. I think it looks most like the bone 3rd row from the bottom, 2nd from the right in your drawings. It's hard to compare what I have in hand to 2 dimensional pics. I will add a few more pics of this bone with other horse astragali that I have to show why I really don't think this one is horse. Gary . . . The best way to photograph bones is at right angles to the front, back, sides, and ends. In this case, you may have some challenge to figure out these aspects of the bone. Frankly, I don't think you're gonna' be able to make this a sloth bone, at least, not a toe bone. The bone you selected as resembling yours -- a proximal phalanx -- is more like a concave/convex cap or like a spacer between the larger bones. I don't see a resemblance. http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
garyc Posted October 24, 2014 Author Share Posted October 24, 2014 I know the last pics were at weird angles. I was trying to show the concavity on the bottom of the bone and that angle seemed to show it best. I agree it does not match any of the sloth bones you showed. I am at a loss. The top side sure looks like an astragalus, but I can't imagine how the bottom side would attach to any calcaneum I've seen. Link to comment Share on other sites More sharing options...
RichW9090 Posted October 24, 2014 Share Posted October 24, 2014 Gary, I sent your pictures to the sloth expert. We see what he says. The plural of "anecdote" is not "evidence". Link to comment Share on other sites More sharing options...
garyc Posted October 24, 2014 Author Share Posted October 24, 2014 Thanks Rich. Link to comment Share on other sites More sharing options...
darrow Posted October 25, 2014 Share Posted October 25, 2014 Gary, I've found small Hipparion teeth on the Brazos a good 10 miles or so down river from Richardson so Pliocene maybe Miocene isn't out of the question. Darrow Link to comment Share on other sites More sharing options...
garyc Posted October 25, 2014 Author Share Posted October 25, 2014 (edited) I think I may have solved my puzzle. Please weigh in with any disagreement, or hopefully, agreement. I do believe now this is a horse astragalus that is fused to the navicular and cuneiform bone and a piece of the calcaneum. I did consider miocene/pliocene as Darrow suggested, but I think the size would suggest equus. This thing is so mineralized and fused to the point there is no appearance that it is more than one bone. It must be pretty old.... I am still confused by the smooth concave surface on the bottom. Please correct me if anything needs correcting. Edited October 25, 2014 by garyc Link to comment Share on other sites More sharing options...
RichW9090 Posted October 25, 2014 Share Posted October 25, 2014 No, I'm not buying a perissodactyl astragalus. The trochlea are lined up straight fore and aft, and all perissodactyl astragali have the trochlea at an oblique angle approaching 45 degrees. The plural of "anecdote" is not "evidence". Link to comment Share on other sites More sharing options...
Harry Pristis Posted October 25, 2014 Share Posted October 25, 2014 I think I may have solved my puzzle. Please weigh in with any disagreement, or hopefully, agreement. I do believe now this is a horse astragalus that is fused to the navicular and cuneiform bone and a piece of the calcaneum. I did consider miocene/pliocene as Darrow suggested, but I think the size would suggest equus. This thing is so mineralized and fused to the point there is no appearance that it is more than one bone. It must be pretty old.... I am still confused by the smooth concave surface on the bottom. Please correct me if anything needs correcting. I can't see what you are suggesting. See if these images help: http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
garyc Posted October 25, 2014 Author Share Posted October 25, 2014 So, if not horse....where else should I be looking. Possibly not an astragalus? Link to comment Share on other sites More sharing options...
garyc Posted October 26, 2014 Author Share Posted October 26, 2014 For those of you who have Frank Kocsis' Vertebrate Fossils: A Neophyte's Guide, look at the metacarpal on the bottom right of page 58 and tell me if you think that is a match. I wish I could see it at other angles. Link to comment Share on other sites More sharing options...
Harry Pristis Posted October 26, 2014 Share Posted October 26, 2014 That image on pp. 58 is of the distal end of a sloth metapodial. Look on pp. 53 for lateral views. Each of these metapodials has a different morphology, particularly the facets on the proximal ends. Of all the metapodials at hand, this one seems to most resemble your find: http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Harry Pristis Posted October 26, 2014 Share Posted October 26, 2014 and . . . http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
garyc Posted October 27, 2014 Author Share Posted October 27, 2014 Harry, the last 2 pics seem really close. I do think it is a sloth metapodial. Rich, any word from your sloth expert? Link to comment Share on other sites More sharing options...
RichW9090 Posted October 27, 2014 Share Posted October 27, 2014 (edited) Yes, Gary. It is a third metatarsal of Megalonyx - it may be a right. Rich Edited October 27, 2014 by RichW9090 The plural of "anecdote" is not "evidence". Link to comment Share on other sites More sharing options...
fossilized6s Posted October 27, 2014 Share Posted October 27, 2014 Cool! Mystery solved. Congrats Gary on the Sloth piece! ~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...
JohnJ Posted October 27, 2014 Share Posted October 27, 2014 Well done, Gary. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
garyc Posted October 27, 2014 Author Share Posted October 27, 2014 Awesome! Thank you so much both Harry and Rich. Link to comment Share on other sites More sharing options...
lissa318 Posted October 27, 2014 Share Posted October 27, 2014 Great find!!! Link to comment Share on other sites More sharing options...
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