Australian Museum Journal Alternatives in malacostracan evolution

Shortform:
Dahl, 1984, Aust. Mus. Mem. 18(1): 1–5
Author(s):
Dahl, Erik
Year published:
1984
Title:
Alternatives in malacostracan evolution
Serial title:
Australian Museum Memoir
Volume:
18
Issue:
1
Start page:
1
End page:
5
DOI:
10.3853/j.0067-1967.18.1984.368
Language:
English
Date published:
31 March 1984
Cover date:
31 December 1983
ISSN:
0067-1967
CODEN:
AUNMA5
Publisher:
The Australian Museum
Place published:
Sydney, Australia
Subjects:
CRUSTACEA: MALACOSTRACA
Digitized:
09 September 2009
Reference number:
368
EndNote package:
EndNote file
Title page:
Title page (112kb PDF)
Complete work:
Complete work (666kb PDF)

Abstract

The Malacostraca appear to have been derived from epibenthic ancestors with many caridoid features. Despite their very long palaeontological record the Phyllocarida differ in so many respects from the basic eumalacostracan morphological and functional plan that they are regarded as unlikely ancestors and more probably an early diverging branch. The general morphology of the malacostracan cephalothorax and carapace is discussed and it is shown that the concept of a maxillary segment carapace common to all Crustacea is not valid. The malacostracan dorsal shield is produced by a fusion of terga and a free carapace fold is sometimes formed at its posterior margin. Some functional systems of the various caridoid Malacostraca are discussed. Attention is drawn to the unsolved problem of secondary segmentation after the alleged loss of a cephalothorax, e.g. in the Syncarida. The unsatisfactory status of the diagnosis of the superorder Peracarida is pointed out and a revision recommended.