This is no thread which is really ceph-related, but as sperm whales are among the most important predators of many larger squids-species, this has at least a little relation to prehistoric squid ecology (and could be interesting for other reasons too). The modern sperm whales are among the most spectacular and highest evolved mammalian predators which ever existed, but despite their huge size they feed mainly from comparably small and petite prey and they show no aggressions towards other marine mammls, which is probably a result of their high grade of specialization on squid (and also fish). In contrast to this gentle giants, some of their distantly related forefathers had a much more aggressive lifestyle. I knew already of some early spermwhales, but only a short time ago I discovered that this animals were probably very fierce hunters in the prehistoric seas, and acted very similar to modern orcas, which did still not existed at this time. Here are some descriptions about them: Killer sperm whale: a new basal physeteroid (Mammalia, Cetacea) from the Late Miocene of Italy GIOVANNI BIANUCCI* and WALTER LANDINI Zygophyseter varolai, a new genus and species of Physeteroidea (Cetacea, Odontoceti), is based on an almost complete skeleton from the Late Miocene (Tortonian) in southern Italy. The extreme elongation of the zygomatic process of the squamosal and the circular supracranial basin (probably for housing the spermaceti organ) delimited by a peculiar anterior projection of the supraorbital process of the right maxilla are the most distinctive features of this bizarre sperm whale. Large body size, large teeth present in both lower and upper jaw, and anteroposteriorly elongated temporal fossa and zygomatic process of the squamosal indicate that this cetacean (for which we suggest the English common name killer sperm whale) was an active predator adapted to feeding on large prey, similarly to the extant killer whale (Orcinus orca). A phylogenetic analysis reveals that Zygophyseter belongs to a Middle?Late Miocene clade of basal physeteroids, together with Naganocetus (new genus for the type of 'Scaldicetus' shigensis). Moreover, the phylogenetic analysis shows evidence of a wide physeteroid radiation during the Miocene and that the extant Physeter and Kogia belong to two distinct families that form a clade representing the crown-group Physeteroidea. © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society, 2006, 148, 103?131. Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae Oliver Hampe Museum für Naturkunde der Humboldt-Universität zu Berlin, Invalidenstraße 43, D-10115 Berlin Abstract Hoplocetus ritzi n. sp. is a new hoplocetine physeterid from the Bolboforma fragori /subfragoris Zone of the middle/late Miocene mica-clay of Groß Pampau in Schleswig-Holstein, North Germany. The Hoplocetinae are known from the early Miocene to the Pliocene. Comparative studies of cranial characters and tooth morphology allow an emended diagnosis of the Hoplocetinae Cabrera, 1926. Four genera, Diaphorocetus, Idiorophus, Scaldicetus, and Hoplocetus are included in this subfamily. The pattern of functional tooth wear deduced from the described Hoplocetus ritzi n. sp. remains is reminescent of that known from Orcinus orca. The hoplocetine physeterids possibly occupied the killer whale niche before the killer whales appeared during the middle Pliocene. Picture of the killer-sperm-whale Aulophyseter: http://www.gem.hi-ho.ne.jp/aquaheart/aulophyseter.gif On the last page of this pdf-article is a photo of a skeleton of such a killer sperm whale: http://collections.nhm.org/newsletters/pdfs/2006-01.pdf Note the comparably short and very robust mandibula and maxilla with the large palatinal teeth. The snout is also very stout and completely different from those of modern sperm or pygmy sperm whales. The skull resembles much more those of the recent orca: http://www.amonline.net.au/mammals/images/marine/400/killer_whale.jpg In contrast the highly elongated and very thin "tweezer"jaws of recent sperm whales with lacking palatinal teeth: http://www.museum.vic.gov.au/bioinformatics/mammals/images/macroside1.jpg It would be very interesting to know what effects the evolution of sperm whales had on the evolution of squids (and I suppose it had a strong impact) and if there were already other large squid-eaters before the development of squid-eating sperm whales.