| Metazoa |  |
Diplopoda |
| MYRIAPODA | Diplopoda |
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Myriapoda |--Symphyla |--Pauropoda |--Diplopoda | |--Penicillata | `--+--Archipolypoda | `--Chilognatha | |--Pentazonia | | |--Glomeridesmida | | |--Sphaerotheriida | | `--Glomerida | `--Helminthomorpha | `--Eugnatha `--Chilopoda |
Millipedes have an elongated body with many segments. On each segment (excluding
the head) there are two pairs of legs and two pairs spiracles for breathing.
The term Diplopoda - "double legs" - refers to the fact that each body
segment bears two pairs of legs. Millipede segments are formed in
early development by fusion of two adjacent embryonic segments (apart from
the first four trunk segments, which remain single). There
are only 3 pairs legs at birth, and in fact baby millipedes look remarkably
like tiny wingless insects, this being indicative perhaps of the close
relationship between the groups (insects being in effect neotonous myriapods).
Movement is through a slow but powerful gait, the pairs of legs moving
in synchronized manner like waves running down the body.
The millipede head bears a single pair of maxillae fused to form a flattened plate (gnathochilarium). The third trunk segment bears the gonopores. Reproduction is through direct and indirect sperm transfer. Some types have simple eyes (ocelli), others are blind. Tergites are sclerotised and calcified
Millipedes are generally scavengers or herbivores, feeding on decaying vegetation, although a few species are carnivorous. Millipedes are timid creatures and coil up when threatened. They also have stink glands for protection. They are long-lived, more than 10 years. Size ranges from 2 mm to 28 cm. There are about 10,000 living species. Millipedes prefer moist habitats.
The oldest definite millipede fossils date to the late Silurian. More are known from the Devonian and Carboniferous. It is likely that these creatures, among the first animal life to come up onto land, played an important role in the Paleozoic terrestrial ecosystem.
Two alternative classifications of extand diplopods:
| Subclass Penicillata
(no orders designated) Subclass Chilognatha |
Subclass Penicillata
Order Polyxenida Subclass Chilognatha |
|
Superorder Pentazonia
Order Glomerida Order Glomeridesmida Order Sphaerotheriida |
Infraclass Pentazonia
Order Glomeridesmida Order Sphaerotheriida Order Glomerida |
|
Superorder Colobognatha
|
Infraclass Helminthomorpha
(no subterclass named) Order Siphoniulida Subterclass Colobognatha Order Platydesmida Order Polyzoniida |
|
Superorder Helminthomorpha
Order Chordeumida Order Polydesmida Order Julida Order Spirobolida Order Spirosteptida |
Subterclass
Eugnatha
Superorder Nematophora Order Stemmiulida Order Callipodida Order Chordeumatida Superorder Merocheta Order Polydesmida Superorder Juliformia Order Spirobolida Order Spirostreptida Order Julida |
| ref: The Diplopoda (Millipedes) (former site) | ref: 
A Checklist of the
Metazoa 5 |
 |
Links | |
MYRIAPODA - brief lecture notes byJamie Seymour
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page uploaded 7 May 2002
checked ATW050113 page © M. Alan Kazlev cladogram by M. Alan Kazlev (modified from original by Mikko Haaramo) bars and buttons from Jelane's families of graphics this material may be freely used for non-commercial purposes |
