An updated phyletic classification and palaeohistory of the Amphipoda
Bousfield, E.L. (1983). An updated phyletic classification and palaeohistory of the Amphipoda, in: Schram, F.R. (Ed.) Crustacean phylogeny. Crustacean Issues, 1: pp. 257-277
In: Schram, F.R. (Ed.) (1983). Crustacean phylogeny. Crustacean Issues, 1. A.A. Balkema: Rotterdam. ISBN 90-6191-231-8. 372 pp., more
In: Schram, F.R. (Ed.) Crustacean Issues. Balkema/CRC Press/Taylor & Francis: Rotterdam. ISSN 0168-6356; e-ISSN 2155-5397, more
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| Abstract |
Based on new materials and a reappraisal of natural classificatory concepts proposed earlier (Bousfield 1977, 1979), an updated classification of amphipod subordinal, superfamily, and family groupS is presented. The arrangement of superfamilies is slightly altered, but modifications reflect more closely recent new taxonomic concepts and the overall p1esio-apomorphic range of character states within the higher taxa. Notable changes include submergence of superfamily Niphargoidea as a family within the reconstituted superfamily Crangonyctoidea; transfer of superfamily Gammaroidea to the base of the Melphidippoidea and superfamily Bogidielloidea to a position near the Melphidippoidea and Hadzioidea; transfer of Phreatogammaridae Bousfield to Melphidippoidea and Paracrangonyctidae Bousfield to superfamily Liljeborgioidea; creation of Paraleptamphopus family group within superfamily Eusiroidea, and Paracalliope family group within the Oedicerotoidea; the formal recognition of all these changes await confirmation by colleagues now publishing on those groupS. The assessment of p1esio-apomorphy of character states, and its use in defining superfamily concepts is described. Within the superfamily Oedicerotoidea, recent studies on the antipodal genera and outgroup families demonstrate a strong ecological basis to the p1esio-apomorphic condition and range of character states. A probable palaeohistory of the Amphipoda is reconstructed from (1) the limited fossil record of the amphipods themselves and more extensive fossil records of animals and plants with which they are intimately associated; (2) modern distributions of amphipod subgroups of low vagility and low eurytopicity, in relation to established geochronology of present-day continents, oceans, and lacustrine basins in which the animals are endemic; and (3) comparative morphological relationships of higher amphipod taxa. The most modern and specialized subordina1 and super-family groups evolved during and since Cretaceous times, the more primitive extant groups probably date from the Jurassic, but the ancestral, prototype amphipods may not have appeared before the Triassic or possibly late Palaeozoic. |
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