现代抹香鲸的嘴在所有四足动物中是最大的，但它们的牙齿相对较小，仅限于下颚，并且它们是以吸的方式进食的。然而，化石记录中大牙齿的发现却表明，捕食性抹香鲸曾经是存在的，其习惯与今天的逆戟鲸相似，但要大得多。现在这一点得到了证明：研究人员在秘鲁中新世地层中发现了一个捕食性抹香鲸的化石牙齿和颌骨，这头抹香鲸几乎与现代抹香鲸一样大，但却有一个三米长的头和长满牙齿的颌骨。

这种动物很可能能够以与现代逆戟鲸相似的方式捕食大型海洋脊椎动物，也许在距今1200万年前中等大小的须鲸数量很多。

原文出处：

Nature doi:10.1038/nature09067

The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru
Olivier Lambert,Giovanni Bianucci,Klaas Post,Christian de Muizon,Rodolfo Salas-Gismondi,Mario Urbina& Jelle Reumer

The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths1, 2. 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) feeders4, 5, 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 far6, 7, 8. 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.