Staphyliniformia is a large
infraorder
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. It contains over 70,000 described species from all regions of the world. Most species occur in moist habitats - various kinds of rotting plant debris, fungi, dung, carrion, many live in fresh water.
Characteristics
Most Staphyliniforms are small to average sized beetles. The diverse group has few clear
apomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...
. They have primitively 11-segmented antennae, a constricted neck well behind the eyes. The
pronotum
The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum ( dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...
has a well defined, large lateral edge. Larval legs are 5-segmented, the 10th abdominal segment is often with more-or-less fine or strong spines or hooks. Urogomphi (paired "horns" at posterior tip of abdomen of larvae and pupae) with basal articulation.
[M.Hansen. Phylogeny and classification of the staphyliniform beetle families (Coleoptera). Biologiske Skrifter 48, Copenhagen, 1997]
Systematics and evolution
Staphyliniformia belongs to the suborder
Polyphaga and is usually given an
infraorder
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 ...
or series
rank
Rank is the relative position, value, worth, complexity, power, importance, authority, level, etc. of a person or object within a ranking, such as:
Level or position in a hierarchical organization
* Academic rank
* Diplomatic rank
* Hierarchy
* ...
. It contains three superfamilies:
*
Histeroidea, including the
clown beetles.
*
Hydrophiloidea, including the
water scavenger beetles
*
Staphylinoidea, including
antlike stone beetles,
carrion beetle
Silphidae is a family of beetles that are known commonly as large carrion beetles, carrion beetles or burying beetles. There are two subfamilies: Silphinae and Nicrophorinae. Nicrophorines are sometimes known as sexton beetles. The number of sp ...
s, and
rove beetle
The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra (wing covers) that typically leave more than half of their abdominal segments exposed. With roughly 63,000 species in thousands of genera, the ...
s.
Some recent studies also include the superfamily
Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily and some 200 new species are described each year. Its constituent families are also undergoing r ...
(infraorder Scarabaeiformia), forming together the so-called Hydrophiloid lineage. A
sister group relationship of Hydrophiloidea and Histeroidea is strongly supported.
The unambiguous fossil record dates back to
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
, and an early
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 ...
origin of the group is probable.
[Grimaldi, D. and Engel, M.S. (2005)]
Evolution of the Insects
Cambridge University Press
See also
*
List of subgroups of the order Coleoptera
This article classifies the subgroups of the order Coleoptera (beetles) down to the level of families, following the system in "Family-group names in Coleoptera (Insecta)", Bouchard, et al. (2011), with corrections and additions from 2020, with c ...
References
*
{{Taxonbar, from=Q383230
Insect infraorders
Taxa named by Auguste Lameere