All 4 pics are of the same rock. There are 2 distinct patterns on here and I've never encountered this before. These pics are from my phone, I'll get better ones later if needed for ID assistance.
I found this in the creek bed in Collin County, TX.
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All 4 pics are of the same rock. There are 2 distinct patterns on here and I've never encountered this before. These pics are from my phone, I'll get better ones later if needed for ID assistance.
I found this in the creek bed in Collin County, TX.
Looks like the septa (inside of the ammonite wall).
That's exactly what these represent. The fluted surfaces are the evidence (an internal cast) of the walls (septa) of a large ammonoid shell. These walls separate chambers (camerae) in the shell. Each wall was laid down sequentially at the rear of the living chamber as the animal grew in size.Quote:
Originally Posted by Mosasaurfiend