Harry Pristis Posted September 15, 2009 Share Posted September 15, 2009 Here's a quiz: What is this bone and what taxon does it represent? There are representatives of this taxon found world-wide over a long span of geological time. You might find a homologue in NJ or VA or MD or TX or many other places (not a geographical clue...just a tease for all the collectors in those states!). Share your deductive reasoning. Partial answers may earn approbrium but win no gold. 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...
Metopocetus Posted September 15, 2009 Share Posted September 15, 2009 Marine or terrestrial? Link to comment Share on other sites More sharing options...
Harry Pristis Posted September 15, 2009 Author Share Posted September 15, 2009 Marine or terrestrial? I will give an answer to this query even though this is not a "20 Questions" format: . . . Yes. The image shows a Miocene specimen from Florida; but, this is a conservative taxon, so you could expect to see a similar shape in homologues both earlier and later. 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...
Pool Man Posted September 15, 2009 Share Posted September 15, 2009 I'll take a wild guess, based on a picture in a book and the size of the bone. And that is seems to have multiple joint surfaces. Is it a crocadilian Astragulus? Dan Link to comment Share on other sites More sharing options...
JohnJ Posted September 15, 2009 Share Posted September 15, 2009 I will give an answer to this query even though this is not a "20 Questions" format: . . . Yes. ... Come on Harry; are you trying to humer us? The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Metopocetus Posted September 15, 2009 Share Posted September 15, 2009 I'll take a wild guess, based on a picture in a book and the size of the bone. And that is seems to have multiple joint surfaces. Is it a crocadilian Astragulus? Dan I too was thinking along those lines, however I was thinking calcaneum...but to what I am not sure. Link to comment Share on other sites More sharing options...
PaleoPutz Posted September 16, 2009 Share Posted September 16, 2009 I too was thinking along those lines, however I was thinking calcaneum...but to what I am not sure. I was thinking along these lines as well, but I think it is not long enough for a calcaneum. Link to comment Share on other sites More sharing options...
Metopocetus Posted September 16, 2009 Share Posted September 16, 2009 I was thinking along these lines as well, but I think it is not long enough for a calcaneum. Agreed most appear to be elongate, perhaps the tarsals or carpals. Link to comment Share on other sites More sharing options...
PaleoPutz Posted September 16, 2009 Share Posted September 16, 2009 Agreed most appear to be elongate, perhaps the tarsals or carpals. I think that is closer... something like a scaphoid? I'm really not very good at isolated bones. Link to comment Share on other sites More sharing options...
Harry Pristis Posted September 16, 2009 Author Share Posted September 16, 2009 I'll take a wild guess, based on a picture in a book and the size of the bone. And that is seems to have multiple joint surfaces. Is it a crocadilian Astragulus? Dan Yes, John, I was trying to avoid answering the question. When you find such a bone in stream lag deposits, there won't be any opportunity to ask 20 questions. For the sake of this quiz, assume that you just found this bone on a gravel bar at the mouth of a river where it meets the sea. All the surrounding sediments you can identify are Tertiary in age. You're alone on the beach with only three or four field guides in your backpack to help with an ID. Now, 'Pool Man' has the right idea . . . take the bit of information you have, and make some comparisons and deductions. His guess of "crocodilian astragalus" fits the clues nicely, though it is wrong. I'm not sure I've ever found a crocodilian astragalus . . . anyone have an image? So, don't give up. This bone is a common fossil, though not very common (in my experience) from this well-known animal. I'm not sure why that is. 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...
siteseer Posted September 16, 2009 Share Posted September 16, 2009 Here's a quiz: What is this bone and what taxon does it represent? There are representatives of this taxon found world-wide over a long span of geological time. You might find a homologue in NJ or VA or MD or TX or many other places (not a geographical clue...just a tease for all the collectors in those states!). Share your deductive reasoning. Partial answers may earn approbrium but win no gold. I thought I had a specimen just like that but maybe I just saw one recently. Is it a sea turtle calcaneum? Link to comment Share on other sites More sharing options...
Cris Posted September 16, 2009 Share Posted September 16, 2009 I thought I had a specimen just like that but maybe I just saw one recently. Is it a sea turtle calcaneum? Turtle is what I've been thinking since this was posted, but I couldn't even begin to guess which bone. Link to comment Share on other sites More sharing options...
worthy 55 Posted September 16, 2009 Share Posted September 16, 2009 Astragali of a Tapir ? It's my bone!!! Link to comment Share on other sites More sharing options...
Harry Pristis Posted September 16, 2009 Author Share Posted September 16, 2009 Several posters are dancing around the correct answer. One or two have the correct bone, but the wrong taxon. One or two have the correct taxon but the wrong bone. Most have deduced the correct SUPERLEGION or even the correct SUPERCOHORT (I was looking for an excuse to use new words!). I take that to mean we're close to the point of diminishing returns for this quiz. There's still a golden kudo waiting for the most persistent; but, I'll post the answer tomorrow mid-day. 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...
siteseer Posted September 16, 2009 Share Posted September 16, 2009 Astragali of a Tapir ? A tapir astragulus looks much like that of a horse - the single pulley as opposed to the double pulley of an artiodactyl. Link to comment Share on other sites More sharing options...
MOROPUS Posted September 16, 2009 Share Posted September 16, 2009 Camel astragali? Tapir calcaneum? Link to comment Share on other sites More sharing options...
kauffy Posted September 16, 2009 Share Posted September 16, 2009 based on structure of the bone i would say its a calcaneum. I say it is some form of turtle calcaneum ( Testudines? ). Based upon the fact you mention its a conservative taxon, you could expect to see similar shape in homologues both earlier and later. Turtles first appeared in the cretaceous (approx 110mya) and have remained structurally similar over this period (conservative taxon) and due to this you can expect that the structure of their foot articulation would remain similar, homologous structures (between differring genus/species). They are extant, and quite common and have a global distribution, and as far as my research tells me turtle calcaneum are relativley rare. (couldnt find any examples on the web so really im sorta guessing....a relativley educated guess ) "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...
Harry Pristis Posted September 16, 2009 Author Share Posted September 16, 2009 (edited) based on structure of the bone i would say its a calcaneum. I say it is some form of turtle calcaneum ( Testudines? ). Based upon the fact you mention its a conservative taxon, you could expect to see similar shape in homologues both earlier and later. Turtles first appeared in the cretaceous (approx 110mya) and have remained structurally similar over this period (conservative taxon) and due to this you can expect that the structure of their foot articulation would remain similar, homologous structures (between differring genus/species). They are extant, and quite common and have a global distribution, and as far as my research tells me turtle calcaneum are relativley rare. (couldnt find any examples on the web so really im sorta guessing....a relativley educated guess ) Nice, detailed rationale for your guess, 'kauffy'! I can see that you are absorbing knowledge at a prodigious pace. But, it's not turtle. In fact, 'siteseer' has already proposed "sea turtle calcaneum." The mystery bone is a calcaneum . . . hats off to those that identified the bone. This calcaneum is crocodilian -- a late Miocene Alligator mississippiensis. Superlegion REPTILIA Sublegion ARCHOSAURIA Supercohort CROCODYLOTARSI Superorder CROCODYLOMORPHA Order CROCODYLIA Suborder BREVIROSTRES In my experience, these are not very commonly found as fossils. (What's your experience, Nate?) I don't think I have ever found the articulating astragalus. Thanks for participating! Edited September 16, 2009 by Harry Pristis 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...
JohnJ Posted September 16, 2009 Share Posted September 16, 2009 (edited) alligator calcaneum (halfway down the page on the right) 30 seconds too late Edited September 16, 2009 by JohnJ The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Seldom Posted September 16, 2009 Share Posted September 16, 2009 (edited) This was a very educational thread and very enjoyable. Thanks Harry and everyone who had input. This is just one of several reasons I love this forum. But what do I know I think tracers cat is cool. But really thanks guys. Edited September 16, 2009 by Seldom Galveston Island 32 miles long 2 miles wide 134 bars 23 liquor stores any questions? Evolution is Chimp Change. Life is not about waiting for the storm to pass; it's about learning to dance in the rain! "I like to listen. I have learned a great deal from listening carefully. Most people never listen." Ernest Hemingway Link to comment Share on other sites More sharing options...
PrehistoricFlorida Posted September 16, 2009 Share Posted September 16, 2009 In my experience, these are not very commonly found as fossils. (What's your experience, Nate?) I don't think I have ever found the articulating astragalus. I have found several alligator astraguli, but only one calcaneum. www.PrehistoricFlorida.com Link to comment Share on other sites More sharing options...
PaleoPutz Posted September 16, 2009 Share Posted September 16, 2009 Ah, the fact that it is crocodilian would explain its appearance to me... From my perspective anyway. It was fun.. Thank you Link to comment Share on other sites More sharing options...
kauffy Posted September 17, 2009 Share Posted September 17, 2009 Nice, detailed rationale for your guess, 'kauffy'! I can see that you are absorbing knowledge at a prodigious pace. But, it's not turtle. In fact, 'siteseer' has already proposed "sea turtle calcaneum." The mystery bone is a calcaneum . . . hats off to those that identified the bone. This calcaneum is crocodilian -- a late Miocene Alligator mississippiensis. Superlegion REPTILIA Sublegion ARCHOSAURIA Supercohort CROCODYLOTARSI Superorder CROCODYLOMORPHA Order CROCODYLIA Suborder BREVIROSTRES In my experience, these are not very commonly found as fossils. (What's your experience, Nate?) I don't think I have ever found the articulating astragalus. Thanks for participating! oops i must have missed siteseer's post! Great thread Harry! make some more, they are a lot of fun! "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...
siteseer Posted September 17, 2009 Share Posted September 17, 2009 oops i must have missed siteseer's post! Great thread Harry! make some more, they are a lot of fun! Yes, that was a great one. It had me looking through my books and articles (couldn't find one book that might have had the answer). I thought I had it with sea turtle because I have seen a bone like that from Sharktooth Hill where crocs are almost off the list (one or two teeth at the Buena Vista Museum) but sea turtles are merely uncommon (most often-found remains would be shell elements from a leatherback). Link to comment Share on other sites More sharing options...
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