Abstract
Discussions of phylogenetic studies based on morphological data focus mainly on results of the cladistic analysis while
selection and evaluation of characters themselves are often underrepresented. Our paper seeks to address this with a survey
of characters of the circulatory organs to contribute to the analysis of phylogenetic relationships of hexapod orders. The
survey is based on examination of literature and includes, in addition, numerous unpublished data. Of 38 variable traits of the
dorsal vessel and the various accessory circulatory organs, we selected 11 which are potentially informative at supraordinal
level. They are critically discussed and coded as characters for use in comprehensive future cladistic analyses employing
greater sets of morphological data. It must be stated that many features of circulatory organs for higher systematic categories
are still based on one or few species for most orders of hexapods; this defi ciency is due to the great methodological effort
required to investigate internal organs. In general, circulatory organs of hexapods are simply organized making it diffi cult
to discriminate homology from convergence. In addition to phylogeny, general aspects of the evolution of the circulatory
system are outlined. In an appendix we provide comprehensive information on the traits, characters and the species in which
they occur.
Translated title of the contribution | Phylogenetic relationships of the orders of Hexapoda:contributions from the circulatory organs for a morphological matrix |
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Original language | German |
Pages (from-to) | 165-203 |
Number of pages | 39 |
Journal | Arthropod Systematics & Phylogeny |
Volume | 64 |
Issue number | 2 |
Publication status | Published - 2006 |
Austrian Fields of Science 2012
- 106012 Evolutionary research
- 106046 Animal anatomy