ID 45mm thick fossil

[RescueMJ]

I found a unique reddish colored 45mm thick fossil while on my walk yesterday. It is pentagon shaped. Longest distance is from side 6-4 and is 9cm. The dorsal side is darker than the ventral. Four of the sides are smooth. Side 6 has a smooth surface and is size of a quarter. Found in area of Pleistocene material.  My guess was neural (4) from a tortoise. Based on drawing in Hulbert's book The Fossils Vertebrates of Florida (p. 122).

 

The thickness of this fossil is what is raising the question for me?

ID help is greatly appreciated.

SIDE 1

SIDE 2

 

  SIDE 3

 

  SIDE 4

 

  SIDE 5

 

  SIDE 6

  SIDE 7

 

[Shellseeker]

Slides #4 and #6 makes me think it is a vertebrae.

[RescueMJ]

On 7/22/2020 at 12:55 PM, RescueMJ said:

I found a unique reddish colored 45mm thick fossil while on my walk yesterday. It is pentagon shaped. Longest distance is from side 6-4 and is 9cm. The dorsal side is darker than the ventral. Four of the sides are smooth. Side 6 has a smooth surface and is size of a quarter. Found in area of Pleistocene material.  My guess was neural (4) from a tortoise. Based on drawing in Hulbert's book The Fossils Vertebrates of Florida (p. 122).

 

The thickness of this fossil is what is raising the question for me?

ID help is greatly appreciated.

SIDE 1

SIDE 2

 

  SIDE 3

 

  SIDE 4

 

  SIDE 5

 

  SIDE 6

  SIDE 7

 

I sent these photos off to Dr. Richard C. Hulbert Jr., Division of Vertebrate Paleontology at the Florida Museum of Natural History.

He sent me a reply within 8 hours.  His answer was "part of a much larger bone, likely from something like a ground sloth, mammoth, or mastodon. But not enough of it remains to positively ID it to either which species or which bone of the skeleton."  At least my wife now knows it was a fossil and not another rock