Abstract of Daniel L. Geiger's papers


Distribution and biogeography of the Haliotidae (Gastropoda: Vetigastropoda) world-wide.
Geiger, D. L. 2000. Bollettino Malacologico 35: 57-120.

The distribution of all 56 abalone species is documented based on specimen records. The three models for the origin of the family (Pacific Rim, Indo-Pacific, Tethys) are evaluated. The area cladogram, which treats the distribution of the individual species as characters and the areas as taxa, is in general agreement with an unrooted phylogenetic tree of the taxa for which the geographic occurrence is superimposed. The basal node of the area cladogram is a fairly large polytomy uniting rather distant provinces such as the north Pacific, Australia, and Africa. A similar pattern emerges from the taxon cladogram. Accordingly, a very general Indo-Pacific origin emerges, best in agreement with the Indo-Pacific model for the origin of the family. The apparent discrepancy with the fossil record is discussed. Although the earlierst fossils from the Upper Creatceous have been found in the Caribbean and in California, a major hiatus of on the order of 200 million years can easily account for the discrepancy between the earliest fosssils and the biogeographical reconstruction, as well as for the large basal polytomy in the biogeographical analysis. All species are illustrated, inlcuding some distinct forms of juveniles, and 30 photographs of live animals.

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