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 prey; 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.
Nyangumi mkubwa wa kisasa, Physeter macrocephalus, mmoja wa wawindaji wakubwa zaidi wanaojulikana, hula cephalopods katika kina kirefu. Kwa kuwa hawana meno ya juu, wanategemea kunyonya ili kuwakamata mawindo yao; kinyume chake, nyangumi kadhaa wadogo wa Miocene (Physeteroidea) wamefafanuliwa kama wafugaji wa raptor (kinyume na kunyonya), sawa na nyangumi wa kisasa Orcinus orca. Ingawa meno makubwa sana ya physeteroid yamegunduliwa katika maeneo mbalimbali ya Miocene, mabaki ya fuvu la kichwa ya utambuzi hayakuonekana hadi sasa. "Kama ilivyoelezwa hapo juu, ""mnyama wa whale wa spermatium"" kutoka Miocene ya kati ya Peru (karibu miaka milioni 12 iliyopita) aliitwa Leviathan melvillei, na alitajwa kwa msingi wa fuvu la kichwa na meno na mandibula." Kwa kichwa cha urefu wa mita 3, meno makubwa ya juu na ya chini (kipenyo cha juu na urefu wa sentimita 12 na zaidi ya sentimita 36), taya zenye nguvu na fossa ya muda mrefu zaidi kuliko ya Physeter, hii ni moja ya wawindaji wakubwa zaidi wa raptor na, kwa maarifa yetu, tetrapod kubwa zaidi iliyowahi kupatikana. Kuonekana kwa nyangumi wakubwa wa aina ya raptor katika rekodi ya visukuku kunapatana na hatua ya utofauti na kuongezeka kwa ukubwa wa nyangumi wa aina ya baleen-bearing mysticetes katika Miocene. Sisi kupendekeza kwamba Leviathan kulishwa hasa juu ya high-nishati maudhui ya ukubwa wa kati baleen nyangumi. Kama mnyama mkubwa zaidi, pamoja na papa mkubwa wa wakati huo Carcharocles megalodon, labda ilikuwa na athari kubwa kwa muundo wa jamii za baharini za Miocene. Uendelezaji wa kisima kikubwa cha juu ya fuvu la kichwa katika Leviathan, kinachopanuka kwenye rostrum kama katika Physeter, inaweza kuonyesha uwepo wa kiungo cha spermaceti kilichoongezwa katika zamani ambacho hakihusiani na kupiga mbizi kwa kina au kulisha kwa lazima.