01 August 2006

Land snails of Turkey: Zonites osmanicus


We collected these shells on and around Honaz Mountain, southeast of Denizli, Turkey, during our survey earlier last month. I identified them tonite about an hour ago. First I thought they were Z. casius, a species that had been recorded from the general area. But they turned out to be flatter and more keeled than Z. casius (see photo below).

Zonites osmanicus (left) and Z. casius (right).

Zonites osmanicus was described by Riedel in 1987 (Annales Zoologici, 41:1-42). It is endemic to Turkey. In fact, most known Zonites species are endemic to Turkey. They may have originated on some land mass that subsequently got incorporated into the Anatolian Peninsula.


Clare said...

Beautiful little things! I was wondering are these snails completely flat - like ammonites appear (to me) to be? And so cannot be right-handed or left-handed? This is what a fossil-hunter told me when I was on holiday and I'm wondering if that's true.


No, these are not completely flat & even if they were, one could still tell one side from the other, because the umbilicus would be depressed. The fossil hunter was probably referring to certain extinct gastropod species that had both their apexes & umbilicuses depressed, i.e. they were completely planispiral. One can't tell if they were right- or left-handed, because there is no reference point. If you had one with a live snail in it, however, then you'd be able to tell the direction of coiling, because the snail's body would be asymmetric.