The Lower Palaeozoic echinoderm faunas of the British Isles and Balto-Scandia

A great many difficulties are involved in dealing with the relations between the British and the Balto-Scandian echinoderm faunas in Early Palaeozoic times. It is obvious that this is due mainly to two circumstances: the imperfect knowledge of the original composition of the faunas in different areas, and the insufficient exactitude in stratigraphic correlation between the British Isles on the one hand and Scandinavia, Estonia, and the Leningrad district on the other. It is not necessary to review here the various factors which in the course of time have acted upon the consecutive marine biota of different ecological niches and which have been decisive of the nature of the fossil record now available to us. Even Charles Darwin in his Origin of Species, the centenary of which is celebrated this year, devoted a special chapter to these questions which have subsequently received much attention in the literature. The essence of the dilemma was formulated by Wachsmuth and Springer (1897, p. 167) as follows: The trouble is that all our generalizations are necessarily based upon the Crinoids as they are represented in our museums, and not upon the Crinoids as they actually existed in geological time, which is a very different thing.' The term 'Crinoids' may of course be substituted by the name of any other group of echinoderms, or by the name of almost any other fossil group.Wachsmuth and Springer introduced the human factor which should certainly not be neglected. It is a fact that some fossil groups have been subject to a more extensive collecting and a more penetrating study than other groups. Rather trivial matters have played a role in this respect. Henbest (1952, p. 304) observed, for instance, that the 'location of fossil records in relation to centres of education, research, industry, and mining is an important factor in the discovery and description of faunas'