Olfaction in whales: Evidence from a young odontocete of the late Oligocene North Sea

Abstract

An incomplete skull and endocranial cast of a small (about one metre long) toothed whale (Cetacea: Odontoceti) of late Chattian (latest Oligocene) age, from the marine Vejle Fjord Formation in northern Denmark, is preserved in an almost perfect three‐dimensional state. Osteological features suggest physical immaturity, but not a very early developmental stage. Preserved parts of the right tympano‐periotic complex include the anterior part of a very large tympanic bulla and attached large malleus, the form of which supports a platanistoid relationship (superfamily Flatanistoidea sensu de Muizon, 1987). Advanced telescoping of the skull and facial asymmetry skewed to the left is combined with a primitive (that is, complex) narial structure. Reduced, but functional olfactory chambers are represented by a subsymmetrical pair of cavities lodged in the ethmoid and three (or four) pairs of ethmoturbinals associated with a cribriform plate. Olfaction persisted in this whale after cranial specialization had reached a level that is generally associated with the capacity for echolocation.

Keywords:

• Cetacea
• Odontoceti
• Cranial anatomy
• Olfaction
• Oligocene
• North Sea
• Denmark

Notes

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