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‘Sea monster’ whale fossil unearthed

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The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru. The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey3; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders , analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12–13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of the largest raptorial predators and, to our knowledge, the biggest tetrapod bite ever found. The appearance of gigantic raptorial sperm whales in the fossil record coincides with a phase of diversification and size-range increase of the baleen-bearing mysticetes in the Miocene. We propose that Leviathan fed mostly on high-energy content medium-size baleen whales. As a top

predator, together with the contemporaneous giant shark Carcharocles megalodon, it probably had a profound impact on the structuring of Miocene marine communities. The development of a vast supracranial basin in Leviathan, extending on the rostrum as in Physeter, might indicate the presence of an enlarged spermaceti organ in the former that is not associated with deep diving or obligatory suction feeding.These authors contributed equally to this work. * Olivier Lambert & * Giovanni Bianucci. Affiliations; Département de Paléontologie, Institut Royal des Sciences Naturelles de Belgique, Brussels 1000, Belgium * Olivier Lambert. Dipartimento di Scienze della Terra, Università di Pisa, Pisa 56126, Italy  * Giovanni Bianucci.  Corresponding authors; Correspondence to: * Olivier Lambert (olambert@mnhn.fr) or  * Giovanni Bianucci (bianucci@dst.unipi.it). news from: nature.com  ~ Leviathan melvillei is an extinct species of physeteroid whale. Fossilised remains, comprising 75% of the animal’s skull, and large fragments of both jaws and several teeth, were discovered in the Pisco-Ica desert in southern Peru in 2008, in Miocene rocks 12-13 million years old.The discovery of L. melvillei was published in the journal Nature on 30 June 2010. The skull of the sole known fossil of Leviathan melvillei measures 3 metres long, its longest teeth are 36 cm long, and it is thought its overall length would have been in the 13.5-17.5 m range. It was similar in size and appearance to the modern sperm whale. Unlike the sperm whale, however, which only has functional teeth in its lower jaw, Leviathan melvillei had teeth in both jaws, and the teeth were much larger than those found in present-day sperm whales: they are the largest cetacean teeth ever discovered. It is thought to have been an aggressive predator, possibly preying on baleen whales.The fossil skull has a curved basin which suggests it might have had a large spermaceti organ, a series of oil and

wax reservoirs separated by connective tissue. This organ is thought to help modern sperm whales to dive deeply for their prey, squid. However, as it is thought that L. melvillei probably would have hunted baleen whales near the surface, it appears that this organ would have had other functions. Possible suggestions include echolocation, acoustic displays (with the spermaceti organ acting as a resonance chamber) or aggressive headbutting, possibly used against competing males in mating contests, or possibly to batter its prey.The fossil was in found in Miocene rocks 12-13 million years old at Cerro Colorado in the Pisco-Ica desert in southern Peru. The area would have been a shallow lagoon when the whale was alive, and fossil remains of many other animals, including baleen whales, beaked whales, dolphins, porpoises, sharks, turtles, seals and sea birds, have been found at the site. L. melvillei would have been a top predator together with the 20-metre-long giant shark, Carcharocles megalodon.Leviathan melvillei was discovered by Olivier Lambert of the National Museum of Natural History in Paris when he stumbled across the fossil in November 2008 during the final day of a field trip with other researchers.The genus name refers to the biblical Leviathan, whereas the species epithet honours Herman Melville, author of Moby-Dick – the authors of the Nature paper are all fans of the novel and wanted to dedicate their discovery to its author. The fossil was prepared in Lima, and the discovery of L. melvillei was published in the journal Nature on 30 June 2010. At the same time Nature also published a 7 minute long video, with footage of the fossil being excavated and interviews with various researchers involved, available both on its website and on its YouTube channel. The fossil has been placed in the collection of the Natural History Museum in Lima, Peru. ~ GoodNews International

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