現(xiàn)代抹香鯨的嘴在所有四足動物中是最大的,，但它們的牙齒相對較小,，僅限于下顎，并且它們是以吸的方式進食的,。然而,，化石記錄中大牙齒的發(fā)現(xiàn)卻表明，捕食性抹香鯨曾經(jīng)是存在的,，其習慣與今天的逆戟鯨相似,，但要大得多。現(xiàn)在這一點得到了證明：研究人員在秘魯中新世地層中發(fā)現(xiàn)了一個捕食性抹香鯨的化石牙齒和頜骨,，這頭抹香鯨幾乎與現(xiàn)代抹香鯨一樣大,，但卻有一個三米長的頭和長滿牙齒的頜骨。
這種動物很可能能夠以與現(xiàn)代逆戟鯨相似的方式捕食大型海洋脊椎動物,，也許在距今1200萬年前中等大小的須鯨數(shù)量很多,。(生物谷Bioon.net)
生物谷推薦原文出處：
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.
