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Hi all, We are on the last two major topics in this formation before we finish off the entire Fort Apache Limestone Project. This week, we examine the enigmatic two species of Straparollus gastropods in detail, from pin head sized juviniles through teenagers starting to get thier whorl ornaments to 6 inch monsters. The shape of this flat planispiral mollusk is unmistakeable, and to actually be able to see an entire growth series in our fossils was highly enlightening! So without delay, here is a synopsis of our latest photo pictorial on Straparollus. (Full write up with many more images can be found on our palo web site: http://www.schursastrophotography.com/paleo/Fortapache-14.html) Straparollus (Euomphalus) Gastropods from the Permian Fort Apache Limestone East of Payson. This is the only planispiral gastropod to be had in any quantity in the Fort Apache Limestone. The size range of specimens is huge, ranging from pinhead size microscopic juveniles up to six inch monsters found impressed in the limestones. And to add as a bonus - two species are found here in this formation - Straparollus sp. and Straparollus kaibabensis. Straparollus gastropods are unusual in that they have a nearly square cross section of their tubes, and are quite flat on the sides as well. While most Straparollus are rimmed with a linear continuous rib on the outer coils, Straparollus Kaibabensis is nearly unique in that it has nodes or tubercles along its coils instead. This makes it appear at first glance to be a nautiloid, however without any septa or the pear shape opening cephalopods have, they are simply huge gastropods. Winters found both types as well in his GSA Memoir 89 from outcrops all on the Fort Apache Indian reservation. Our finds include many silicified specimens, most partials, and several limestone impressions as molds. Also, they can be very small indeed, the smallest members are best seen in the microscope at 30x magnification. This contrasts with the monstrous specimen we found back in 2006 that was over six inches in diameter! Straparollus (Euomphalus) Kaibabensis - Quick Cam shots The outer 2 or 3 whorls is where the nodes develop in mature specimens. This partial outer arc shows them very well. The entire outside rim of the shell is wider as a result of these ornaments. (Straparollus kaibabensis) Dorsal view of the same conch, which you can see the swelling of the width for every node present. This also gives it a very nautiloid like appearance. (Straparollus kaibabensis) Inside view shows the double wall that is characteristic of Straparollus. This is another feature that differentiates it from nautiloids in the field. (Straparollus kaibabensis) Straparollus (Euomphalus) Kaibabensis - Digicam Shots This big fella was found back in 2006 on an expedition with some museum members on an exploratory hike. I hauled this one back in my back pack over 2 miles to the truck. Its preservation is poor, but you can easily see the nodes. Straparollus (Euomphalus) sp. - Microscope shots A gorgeous miniature Straparollus! You can see the coils have gaps between them here as well. The ridges and nodes have not developed yet. This juvenile is starting to show the beginnings of the linear ribbing. It will grow very fast. While a bit distorted from compression of overlying sediments, this complete specimen shows the linear ridges well and detail all the way into the protoconch. I left it in the limestone along with some beautiful cone shaped gastropods for a composite view of the sea bottom. It almost looks as if its sitting in the bottom muds. Well thats it for this week. This was a really rewarding study of this amazing mollusk. Next week is the really big project - all the rest of the thousands of small gastropods. I promise not to show you ALL of them!