Wooster’s Fossils of the Week: Corkscrew shells from the Pliocene of Cyprus

May 20th, 2012

Steve Dornbos (’97), now a professor at the University of Wisconsin, Milwaukee, and I found these intricate shells by the hundreds in the Nicosia Formation (Pliocene) of Cyprus during his Independent Study field work. (We published this study in 1999.) They are the gastropod (snail) species Turritella tricarinata (Brocchi 1814).

Turritellid snails are still very common today, so we know quite a lot about their ecology and physiology. They are an unusual mix of deposit-feeder and filter-feeder, eating organic particles on the sediment surface and in the water. They do it by creating a current with cilia, drawing water into their mantle cavities. There they have a complex system of tentacles that filter out the largest particles, allowing only the small, digestible goodies onto the surfaces of their gills. The organics are coated with mucus and made into a kind of sticky string that is pulled into the mouth (Graham, 1938). These snails are usually found in large aggregations, just like what we found in the Pliocene of Cyprus.
Turritella tricarinata was originally described by Giovanni Battista Brocchi in 1814 as Turbo tricarinata. Brocchi (1772-1826) was an Italian natural historian who made significant contributions to botany, paleontology, mineralogy and general geology. He was born in Bassano del Grappa, Italy, and studied law at the University of Padova. He liked mineralogy and plants much better than lawyering, though, and became a professor in Brescia. His work resulted in an appointment as Inspector of Mines in the new kingdom of Italy.

Brocchi wrote the first thorough geological assessment of the Apennine Mountains, and he included in it a remarkable systematic study of Neogene fossils. He compared these fossils to modern animals in the Mediterranean — a very progressive thing to do at the time.
Above are drawings made by Brocchi of the turritellid fossils he found in the Apennines during his extensive study published in 1814. Note that in the Continental fashion still followed today, the shells are figured aperture-up. Americans and the rest of the English-speaking world orient them in the proper way.

Brocchi was an adventurous traveler, but it eventually did him in. He died in Khartoum in 1826, a “victim of the climate” and a martyr for field science.

References:

Brocchi, G.B. 1814. Conchiologia fossile subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente. Milano Vol. I: pp. LXXX + 56 + 240; Vol. II, p. 241-712, pl. 1-16.

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.

Graham, A. 1938. On a ciliary process of food-collecting in the gastropod Turritella communis Risso. Proceedings of the Zoological Society of London A108: 453–463.

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