Archive for July 17th, 2011

Wooster’s Fossil of the Week: Pelican’s-foot snail (Pliocene of Cyprus)

July 17th, 2011

This week’s fossil was found on the same 1996 Keck Geology Expedition to Cyprus that produced the Thorny Oyster highlighted in January. Stephen Dornbos (’97) was there, but this fossil was not part of the Pliocene coral reef complex he and I described (Dornbos & Wilson, 1999), but it was in nearby shallow marine embayment muddy sediments.

The pelican’s-foot snail is Aporrhais pespelecani (Linnaeus, 1758). It got its common name before Linnaeus because of its resemblance to a pelican’s webbed foot. When the snail reached a mature size, it extended the outer lip of its aperture into spines as an anti-predatory defense (probably against crabs) and as possibly a way to spread its weight (“footprint”, if you like) on soft sediment.

A. pespelecani belongs to the Superfamily Stromboidea, a very large group that includes familiar snails like the true conch (Strombus). A recent morphological analysis suggests they are also related to the carrier shells (Xenophoridae), although genomic sequencing is needed for support (Simone, 2005).

The pelican’s-foot snail lives today in the eastern Atlantic as well as the Baltic, Black and Mediterranean seas. It is a carnivore on clams and has the ability to “flick” its muscular foot to escape predators.

These distinctive shells have been known in Europe for a very long time. I like this particular illustration by Niccolò Gualtieri (1688–1744) in which they appear to be dancing:

As is often the case with writing these little essays, I learned something about a brilliant scientist now almost forgotten. Niccolò Gualtieri was a Florentine polymath skilled in medicine, poetry, drawing, and the developing natural sciences. He had his own shell museum, so he can be said to be one of the first conchologists.

I’m sure we shared Gualtieri’s delight when we first saw these distinctive shells scattered across a dry Cypriot plain.

References:

Dornbos, S.Q. and Wilson, M.A. 1999. Paleoecology of a Pliocene coral reef in Cyprus: Recovery of a marine community from the Messinian Salinity Crisis. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 213: 103-118.

Gualtieri, N. 1742. Index Testarum Conchyliorum, quae adservantur in Museo Nicolai Gualtieri (“List of the shells of shellfish which are preserved in the museum of Niccolò Gualtieri”).

Manganelli, G. and Benocci, A. 2011. Niccolò Gualtieri (1688–1744): biographical sketch of a pioneer of conchology. Archives of Natural History 38: 174-177.

Simone, L.R.L. 2005. Comparative morphological study of representatives of the three families of Stromboidea and the Xenophoroidea (Mollusca, Caenogastropoda), with an assessment of their phylogeny. Arquivos de Zoologia 37: 141–267.