Thursday

More Fossil Teeth

Finding fossilized horse teeth in the small arroyo was quite a surprise, see previous post.  But another question arose, did these teeth erode out from their original depositional position or were they the result of landscape remodeling?  The fresh breaks on some of the teeth suggested a scenario where the animal died and was covered, followed by a period of mineralization.  The fossilized skeletal remains were then at some point uncovered and moved by environmental forces followed by another period of soil build up which left them where rain would eventually uncover them.  To test this question another trip was required.  This time to remove loose unconsolidated soil from the area where the teeth were found in an effort to locate additional embedded fossilized teeth.  Using a hand brush, the loose sandy soil was removed along the arroyo and in an area between 2 small drainages.  Under a pile of twig and sand debris another tooth was found embedded in the harder soil that lay beneath.  This soil layer also had embedded twigs indicating it was not an old surface but rather was redeposited in the recent past.  Carefully isolating the tooth by removing this harder soil completely uncovered the fragment tooth which was sitting on the hard pan subsoil characteristic of many heavily eroded areas around the estate.  After stabilizing the tooth fragment it was matched with one previously recovered, see image below.  The orientation of this tooth fragment in the soil was also consistent with redeposition.  The top of tooth was pointing uphill and the flat mineralized surface along the jaw line was in a vertical position not horizontal.  The position of this horse tooth fragment also indicates the leaf shaped point found close by was most likely a spurious association and the result of environmental forces.


new mexico fossil horse
Another tooth found after brushing away loose the loose sandy soil, note the twig impression at the bottom suggesting redeposition.
Newest tooth fragment fitted to another tooth.
Under surface of fossil horse teeth showing a flat mineralized surface from the original depositional environment.
Hard pan sub soil upon which rested the newest fossilized tooth.

4 comments:

  1. Quite amazing finding so many fossilize horse teeth!

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  2. I plan to go back with a broom, dustpan, and screen to clear a larger area and pin point any other bone that may be near the surface.

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  3. Sweeping the dirt outside, fun? I do enough of that cleaning the estate. But I did figure out where the teeth fragments came from. I will post my conclusions when I finish writing it up.

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