The Archostemata are the smallest
suborder
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...
of
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
s, consisting 45 living species in five families. They are an ancient lineage with a number of primitive characteristics.
Antennae may be thread-shaped (filiform) or like a string of beads (moniliform). This suborder also contains the only beetles where both sexes are
paedogenic, ''
Micromalthus debilis''. Modern archostematan beetles are considered rare, but were more diverse during the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...
. The term "Archostemata" is used more broadly by some authors to include both modern archostematans as well as
stem-group beetles like "
protocoleopterans", which some modern archostematans closely resemble to due to their
plesiomorphic
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades.
Plesiomorphy, symplesiomorphy, apomorphy, and ...
morphology. Genetic research suggests that modern archostematans are a
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...
group. Some genetic studies have recovered archostematans as the sister group of
Myxophaga.
Taxonomy
There are five extant families.
* Family
Crowsoniellidae Iablokoff-Khnzorian, 1983
* Family
Cupedidae Laporte, 1838
* Family
Micromalthidae Barber, 1913
* Family
Ommatidae Sharp and Muir, 1912
* Family
Jurodidae
Jurodidae is a family of beetles that was originally described for the extinct genus '' Jurodes'', known from the Middle-Late Jurassic of Asia. In 1996, a living species, ''Sikhotealinia zhiltzovae'' was discovered in the Sikhote-Alin mountains ...
Ponomarenko, 1985
See also
*
List of subgroups of the order Coleoptera
References
External links
Tree of Life - Archostemata
{{DEFAULTSORT:Archostemata
Insect suborders
Extant Permian first appearances
Taxa named by Hermann Julius Kolbe