ScienceDaily (Mar. 17, 2010) — It might sound like a mashup of monster movies, but palaeontologists have discovered evidence of how an extinct shark attacked its prey, reconstructing a killing that took place 4 million years ago.
Skeleton of the dolphin, preserved for 4 million years with the bite marks across its ribs from the shark attack the killed it. (Credit: Giovanni Bianucci)
The evidence, published in the latest issue of the journal Palaeontology, comes from the fossilised skeleton of a 2.8-meter-long dolphin discovered in the Piedmont region of northern Italy.
According to Giovanni Bianucci, who led the study: "the skeleton lay unstudied in a museum in Torino for more than a century, but when I examined it, as part of a larger study of fossil dolphins, I noticed the bite marks on the ribs, vertebrae and jaws. Identifying the victim of the attack was the easy part -- it's an extinct species of dolphin known as Astadelphis gastaldii- working out the identity of the killer called for some serious detective work, as the only evidence to go on was the bite marks."
The overall shape of the bite indicated a shark attack, and Bianucci called in fossil shark expert Walter Landini. "The smoothness of the bite marks on the ribs clearly shows that the teeth of whatever did the biting were not serrated, and that immediately ruled out some possibilities. We simulated bite marks of the potential culprits and, by comparing them with the shape and size of the marks on the fossils, we narrowed it down to Cosmopolitodus hastalis."
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Volume 53 Issue 2, Pages 457 - 470
Published Online: 16 Mar 2010
by GIOVANNI BIANUCCI*, BARBARA SORCE*, TIZIANO STORAI† and WALTER LANDINI*
*Dipartimento di Scienze Della Terra, Università di Pisa, Via S. Maria 53, I56126, Pisa, Italy; e-mails bianucci@dst.unipi.it;sorce@dst.unipi.it; landini@dst.unipi.it
†DNAquA – Laboratorio di Ricerche e Studi Sulla Vita Marina, Via S. Carlo Borromeo 1, I09100 Cagliari, Italy; e-mailtizianostorai@dnaqua.it
KEYWORDS
Cetacea • Delphinidae • Elasmobranchia • Italy • Pliocene • bite marks • taphonomy
ABSTRACT
Abstract: Shark bite marks, including striae, sulci and abrasions, in a well-preserved fossil dolphin skeleton referred to Astadelphis gastaldii (Cetacea, Delphinidae) from Pliocene sediments of Piedmont (northern Italy), are described in detail. The exceptional combination of a fossil dolphin having a significant part of the skeleton preserved and a large number of bite marks on the bones represents one of the few detailed documentations of shark attack in the past. Most bite marks have been referred to a shark about 4 m long with unserrated teeth, belonging to Cosmopolitodus hastalis, on the basis of their shape and their general disposition on the dolphin skeleton. According to our hypothesis, the shark attacked the dolphin with an initial mortal bite to the abdomen from the rear and right, in a similar way as observed for the living white shark when attacking pinnipeds. A second, less strong, bite was given on the dorsal area when the dolphin, mortally injured, probably rolled to the left. The shark probably released the prey, dead or dying, and other sharks or fishes probably scavenged the torn body of the dolphin.
Typescript received 16 December 2008; accepted in revised form 14 October 2009
DIGITAL OBJECT IDENTIFIER (DOI)10.1111/j.1475-4983.2010.00945.x
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