Subphylum Myriapoda — Centipedes & Millipedes

Myriapods are terrestrial arthropods with elongated, segmented bodies bearing numerous legs. This group includes centipedes and millipedes, which are commonly found in soil, leaf litter, and under stones or logs. Most myriapods play an important role in ecosystems as predators or decomposers.

Classes of Myriapods

Myriapods are divided into four main classes:

Class Chilopoda — Centipedes
Class Diplopoda — Millipedes
Class Pauropoda — Small soil-dwelling myriapods
Class Symphyla — Garden centipedes

Class Diplopoda — Millipedes

Millipedes are slow‑moving arthropods with long, segmented bodies. Most segments bear two pairs of legs, and they are primarily detritivores, feeding on decaying plant material. When disturbed, many species curl into a tight coil for protection.

Subclass Penicillata — Bristly millipedes

These are small, soft-bodied millipedes with tufts of bristles rather than a hard exoskeleton.

Order Polyxenida — Tiny, soft-bodied millipedes covered in bristles, often found under bark and stones.

Subclass Chilognatha — Typical millipedes

This includes the vast majority of millipedes, with the familiar hard‑bodied cylindrical or flattened forms.

Infraclass Pentazonia — Pill millipedes and relatives

Order Glomerida — Pill Millipedes 🇬🇧
Short, rounded millipedes that can roll into a tight ball for protection.
Order Sphaerotheriida — Giant Pill Millipedes
Large tropical pill millipedes capable of complete enrolment.
Order Glomeridesmida — Small Pill Millipedes
Small, flattened millipedes related to pill millipedes.

Infraclass Helminthomorpha — Worm-like Millipedes

The long-bodied forms most people encounter.

Order Julida — Snake Millipedes 🇬🇧
Cylindrical millipedes found in soil and leaf litter.
Order Spirobolida — Iron Millipedes
Medium to large cylindrical millipedes, often banded.
Order Spirostreptida — Large Tropical Millipedes
Some of the largest millipedes, mostly found in warm regions.
Order Polydesmida — Flat‑backed Millipedes 🇬🇧
Millipedes with wide, flattened segments.
Order Chordeumatida — Small / Bristly Millipedes 🇬🇧
Small millipedes living in leaf litter.
Order Callipodida — Callipodid Millipedes
Elongated millipedes with a somewhat flattened body shape.
Order Stemmiulida — Slender Millipedes
Smooth, cylindrical millipedes.
Order Siphonophorida — Thread Millipedes
Very long, thread-like millipedes with many segments.
Order Siphoniulida — Rare Millipedes
A small, poorly known group.
Order Platydesmida — Flat Millipedes
Broad, flattened millipedes.
Order Polyzoniida — Short‑bodied Millipedes
Short, broad millipedes with a rounded front end.

My Observations

I have encountered a small but varied selection of millipedes in different parts of the world. Locally, I’ve seen the familiar Common Pill Millipede at Waggoners Wells and the Striped Millipede on Crooksbury Common. Further afield, I came across a large yellow‑banded Spirobolus species while descending from the Great Wall at Jinshanling, and a beige cylindrical spirobolid in the rainforest at La Selva, Costa Rica.

Although these species belong to very different orders and families, they all share the characteristic slow, deliberate movement and curled defensive posture typical of millipedes.

Species I have seen

Order Glomerida — Pill Millipedes
- Family Glomeridae
  - Common Pill Millipede (Glomeris marginata) — Waggoners Wells, UK 2019

Order Julida — Snake Millipedes
- Family Julidae
  - Striped Millipede (Ommatoiulus sabulosus) — Crooksbury Common, UK 2020

Order Spirobolida — Iron Millipedes
- Family Spirobolidae — Spirobolid Millipedes
  - Large Beige Cylindrical Millipede — La Selva, Costa Rica 2015
  - Large Yellow‑banded Millipede (Spirobolus sp., likely S. walkeri or S. bungii) — Jinshanling, China 2013

Yellow Banded Millipede (<em>Spirobolus cf walkeri/bungii</em>) — Yellow Banded Millipede (*Spirobolus cf walkeri/bungii*)
— Jinshanling, China 2015

Large Beige Cylindrical Millipede (Family Spirobolidae)
— La Selva, Costa Rica 2015

Striped Millipede - Ommatoiulus sabulosus — Striped Millipede (*Ommatoiulus sabulosus*)
— Crooksbury Common, UK, 2020

Common Pill Millipede - Glomeris marginata — Common Pill Millipede (*Glomeris marginata*)
— Waggoners Wells, 30 Sep 2019

Class Chilopoda — Centipedes

Centipedes are fast‑moving, predatory myriapods with elongated, flattened bodies and one pair of legs per segment. They use venomous front limbs (forcipules) to subdue prey and are typically found in damp environments such as soil, leaf litter, and under stones or logs.

Order Scutigeromorpha — Long-legged Centipedes
Fast, delicate centipedes with extremely long legs, often found indoors.
Order Lithobiomorpha — Stone Centipedes 🇬🇧
Medium‑sized, fast‑moving centipedes commonly found under stones and logs.
Order Scolopendromorpha — Tropical Centipedes
Large, robust predatory centipedes, mostly in warm regions.
Order Geophilomorpha — Soil Centipedes 🇬🇧
Long, slender centipedes with many segments, living in soil and leaf litter.
Order Craterostigmomorpha — — Tasmanian & New Zealand Centipedes
A small, ancient group restricted to Australasia.

My observations

Although I’ve seen many centipedes over the years, this is the only one I’ve managed to photograph clearly enough to identify. I found it locally on a walk in Surrey and was surprised by how long and pale it was — much larger than the small stone centipedes I usually see under logs.

Order Geophilomorpha
→ Family Himantariidae
Western Yellow Centipede (Stigmatogaster subterranea)
— Compton, Surrey, Nov 2023