The Miocene mica clay locality of Groß Pampau, known fornumerous and partly spectacular finds of marine mammals is becoming more andmore a prominent site that bears the potential to resolve questionsregarding taphonomic relationships and to interpret life communities of theancient North Sea because of its rich faunal assemblage includinginvertebrates and other remains of various vertebrate organisms. In thepresent work we describe a right periotic of Physeteroidea withmorphological characters so far unknown from other sperm whales. Theperiotics of the middle Miocene Aulophyseter morricei demonstrate the closest resemblance to theGroß Pampau specimen in their overall appearance and in the generalarrangement and proportions of single structures, particularly of theanterior process and pars cochlearis. A great similarity is also documentedwith periotics of the living sperm whale, Physeter macrocephalus, especially regarding the shape anddisposition of the anterior process and the bony element located dorsally tothe accessory ossicle. Kogiid periotics differ strongly from that of theGroß Pampau specimen by having an inflated and short anterior processand, typically, three well-defined spines on it. A new taxonomic naming ofthe Groß Pampau periotic is not appropriate at this stage, although itmight demonstrate the existence of a so-far undescribed physeteroid species.Additionally, its systematic position remains yet unclear and it is unknownat this point if it could belong to Hoplocetus ritzi, another physeterid, whose fragmentswere discovered in the same locality, or to another, already-described taxon,of which the periotic is still unknown.