Studies over de Nederlandse fossiele cetacea

In this first part of a series on the fossil whales found in Holland the general situation is discussed. Mainly by lack of interest the Dutch fossil whales from the Miocene never have been systematically collected and described. Van Deinse's pioneer work did not stimulate further research. Consequently much material has been lost. The material collected is dispersed over an unknown number of official and private collections. Of these, many collections are in a bad condition. The fossil material mainly consists of isolated pieces of bone (mostly vertebral bodies) almost always more or less damaged. Complete skeletons never have been found; also complete vertebral columns and skulls are lacking. Thus we cannot apply the classical palaeontological methods of reconstruction and determination of the various species. We must start with a study of the osteology dealing with the external form of the bones and the bone architecture. The general morphology of the whale skeleton is discussed. Of the whale physiology special mention of the short period of fast growth of the animals (intra-uterine and during the first year of life) has been made. The whale skeleton is compared with that of big terrestial mammals, thereby stressing the influence of the specific gravity of the aqueous environment of whales on their bone structure.