RE: help me with these 2 snailshells

[giani]

Hello,these are TURBINELLA ANGULATA or Pleuroploca Trapezium Paeteli???

<a href="http://www.badongo.com/pic/10079599" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/10079599">http://www.badongo.com/pic/10079599</a><!-- m --></a>
<a href="http://www.badongo.com/pic/10079600" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/10079600">http://www.badongo.com/pic/10079600</a><!-- m --></a>
<a href="http://www.badongo.com/pic/10079602" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/10079602">http://www.badongo.com/pic/10079602</a><!-- m --></a>
<a href="http://www.badongo.com/pic/10079603" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/10079603">http://www.badongo.com/pic/10079603</a><!-- m --></a>
<a href="http://www.badongo.com/pic/10079604" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/10079604">http://www.badongo.com/pic/10079604</a><!-- m --></a>

[paul monfils]

Definitely Turbinella angulata.  Here are some pics of both species for comparison:

<a href="http://www.gastropods.com/2/Shell_1512.shtml" target="_blank"><!-- m --><a class="postlink" href="http://www.gastropods.com/2/Shell_1512.shtml">http://www.gastropods.com/2/Shell_1512.shtml</a><!-- m --></a>

<a href="http://www.gastropods.com/0/Shell_12100.shtml" target="_blank"><!-- m --><a class="postlink" href="http://www.gastropods.com/0/Shell_12100.shtml">http://www.gastropods.com/0/Shell_12100.shtml</a><!-- m --></a>

These are superficially similar, but here are some specific characteristics to note on your specimens:

- Smooth but thick and mature lip (P. trapezium has small teeth, usually in pairs, on the lip.  An immature P. trapezium may not have them (like the top picture on the linked page), but your shell is obviously fully mature.)

- Three heavy mid-columellar folds (P. trapezium has only a couple of small ridges at the anterior end of the columella, the central part being smooth.)

- The extension of the columella out onto the body whorl.  This is a characteristic of Turbinellidae, not Fasciolariidae.

- The heavy cords on the posterior body whorl, just below the suture (the "sub-sutural ramp").  (Not seen in P. trapezium.)

.  <span class="petit">--Last edited by Paul Monfils on 2010-08-05 03:20:41 --</span>