Monday, July 30, 2007

Un-identified Ammonoids




A very hot day in the West Desert of Utah netted these.

The first (bottom) I have identified as ?Koninckites on the web site, dont know if that ID is anywhere close. Compressed shells with a well rounded venter, the umbillicus is shallow, the umbillical walls almost non-existant, especially on older shells. The only ornamentation is well formed growth lines, not strong enough to be called ribs, but stronger than most growth lines.

The second (top) is tentatively identified as Wyomingites, again, no constrictions as in Xenoceltites, and no ribs as in Kashmirites.
Someday some brite young phD. will revise the taxonomy of the Early Triassic ammonoids and put a smile on my face.

5 comments:

  1. After finding a specimen that shows the sutures (with a little preparation) and looking through Smith 1932 very closely I noticed a very close resemblance of the bottom fossil with Clypeoceras hooveri and now believe this to be an acurate ID. I dont know about the status of Clypeoceras or if hooveri is still a member of that genus.

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  2. The top fossil is Wyomingites arnoldi

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  3. The fossil identified as Clypeoceras is now refered to Guodunites. The Guodunites from the Confusion Range will be described in an upcoming publication yet to be named.

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  4. ARNAUD BRAYARD, THOMAS BRÜHWILER, HUGO BUCHER, JIM JENKS, 2009, Palaeontology, Volume 52 Issue 2, GUODUNITES, A LOW-PALAEOLATITUDE AND TRANS-PANTHALASSIC SMITHIAN (EARLY TRIASSIC) AMMONOID GENUS (p 471-481) http://www3.interscience.wiley.com/journal/122260273/abstract

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