Classification
The living members of the Diplopoda are divided into fifteen orders in three subclasses. The basal subclass Penicillata contains 160 species whose exoskeleton is not calcified, and which are covered in setae or bristles. All other millipedes belong to the Chilognatha in the strict sense.
The subclass Pentazonia contains the short-bodied pill millipedes, which are capable of rolling themselves into a ball ("volvation"). The subclass Helminthomorpha contains the great majority of the species.
The subgroups of millipedes in phylogenetic sequence, from most basal to most advanced, are:
- Basal genus Eileticus (fossil)
- Subclass Penicillata
- Order Polyxenida
- Subclass Arthropleuridea (tentatively placed here; fossil)
- Subclass Zosterogrammida (fossil)
- Subclass Pentazonia
- Basal genus Amynilyspes (fossil)
- Superorder Limacomorpha
- Order Glomeridesmida
- Superorder Oniscomorpha
- Order Glomerida
- Order Sphaerotheriida
- Family Sphaerotheriidae
- Family Sphaeropoeidae
- Subclass Archipolypoda
- Subclass Helminthomorpha
- Superorder Pleurojulida (fossil)
- Superorder Colobognatha (paraphyletic?)
- Order Polyzoniida
- Order Platydesmida
- Order Siphonocryptida (formerly in Polyzoniida)
- Order Siphonophorida
- Superorder "Merocheta"
- Order Polydesmida
- Superorder Nematophora
- Basal genus Hexecontasoma (fossil)
- Order Callipodida
- Order Chordeumatida
- Order Stemmiulida
- Superorder Diplocheta
- Order "Xyloiuloida" (fossil)
- Order Julida
- Order Siphoniulida
- Order Spirobolida
- Order Spirostreptida
Read more about this topic: Millipede