Electronic Supplement 1
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Organisms
Diversity & Evolution 4 (2004) Electronic Supplement 1 |
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Rolf G. Beutel, Albrecht Komarek:
Comparative study of thoracic
structures of adults of Hydrophiloidea and Histeroidea with phylogenetic
implications (Coleoptera, Polyphaga).
print version: Org. Divers. Evol. 4(1-2): 1-34. 2004 (full article)
electr. suppl.:
Part 1. Table (Character state matrix).
pdf-format, 70 KB
Part 2. NEXUS-file for
phylogenetic analysis. txt-format, 14 KB
Abstract:
External and internal structures of adults of
Hydrophiloidea and Histeroidea were examined. Skeletal and muscular features of
Helophorus aquaticus and Margarinotus brunneus are described in
detail. Morphological data are presented as a list of characters and data
matrix, and analysed together with other characters of adults, characters of
larvae, and characters related to reproduction, habitats and feeding habits.
The results of the analysis (characters unweighted) of the full dataset
unambiguously support the monophyly of the following clades: [Scarabaeoidea
(represented by a genus of Lucanidae and a genus of Scarabaeidae) +
Hydrophiloidea + Histeroidea], [Hydrophiloidea + Histeroidea], Histeroidea,
[Sphaeritidae + Histeridae], Hydrophiloidea, Hydrophiloidea (excluding
Helophoridae), Hydrophiloidea (excluding Helophoridae and Hydrochidae),
[Epimetopidae + Georissidae], and [Spercheidae + Hydrophilidae]. The monophyly
of all histeroid and hydrophiloid families and of Hydrophilidae (represented by
hydrophilines and sphaeridiines) excluding Berosus is also supported.
The placement of Scarabaeoidea is in contrast to a taxonomic treatment as a
lineage with the same rank as Staphyliniformia. Hydraenidae are not closely
related to Hydrophiloidea. The clade comprising Hydrophiloidea and Histeroidea
is well supported, but mainly by larval features correlated with predacious
habits. The position of Spercheidae implies that a considerable number of
seemingly plesiomorphic features of the head are due to reversal and
specialised feeding habits (filter feeding). Histeridae show a highly derived
pattern of thoracic features with unusual muscular modifications, a long
horizontal, dorsal part of the mesopleuron, widely separated metacoxae and a
strongly simplified metafurca. Hydrophiloidea are well supported by character
transformations of the thorax and other body parts, which are probably related
to the invasion of the aquatic habitat in the adult stage, e.g. surface
modifications related to the ventral plastron. Georissidae + Epimetopidae are
characterised by derived features, which may be the result of a secondarily
terrestrial or semiterrestrial life style (partly reduced ventral pubescence),
and by a weakly sclerotized mesonotum, mesofurca and metafurca. Hydrochidae,
Georissidae and Epimetopidae show a considerable number of autapomorphies,
whereas Helophoridae are probably close to the groundplan of Hydrophilidae. The
adaptations to an aquatic life style and the specific habits are very different
in Hyrophiloidea and the aquatic groups of Adephaga.
Key words: Staphyliniformia; Hydrophiloidea; Thoracic structures; Phylogeny; Evolution
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