NATO ASI Series Volume 196, 1990, pp 137-162

Evolutionary Morphology and Acoustics in the Dolphin Skull

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Cetaceans are the most fascinating creatures in the animal kingdom. They adapted so perfectly to their aquatic habitat that it is hard to imagine they originated from typical tetrapod land mammals. Naturally, this change to an extremely different habitat brought about profound modifications and specializations in the cetacean sensory world. Dolphins have a fairly effective visual system, which allows good sight above and below the water surface (Nachtigall, 1986; Dral, 1987). The peripheral olfactory system is reduced totally, but still occurs during early ontogenesis (Jacobs et al., 1971; Oelschläger and Buhl, 1985a, b) while the taste organ, in principle, is retained (Nachtigall and Hall, 1984). Cutaneous sensitivity seems to be fairly good in cetaceans (Herman and Tavolga, 1980) and there are indications that dolphins may possess a magnetic sense (Zoeger et al., 1981; Bauer et al., 1985; Kirschvink et al., 1986; Credle, 1988). However, it is the acoustic system, which is clearly dominant and optimized by a highly efficient ultrasound transmitter for echolocation. The latter may be connected functionally with the unusually well-developed terminalis system (Demski et al., 1985; Buhl and Oelschläger, 1986; Oelschläger et al., 1987; Ridgway et al., 1987; Oelschläger, 1989). Some toothed whales presumably can...,“emit sounds so intense that their prey is debilitated and capture made easier” (Norris and Møhl, 1983).