Pachymerium ferrugineum (C.L.Koch, 1835)
- GB IUCN status: Data Deficient
- GB rarity status: Nationally Rare
3 (either 'short' or 'long' form)
Pachymerium ferrugineum is a distinctive and large (to 50 mm body length) reddish-orange centipede with numerous small coxal pores distributed over both the dorsal and ventral surfaces of the coxae of the last legs.
It occurs in two forms: the 'short form' with 43 to 45 leg pairs and the 'long form' with 55 to 59 leg pairs.
More information to allow accurate identification is given in the published identification keys by Tony Barber (2008 & 2009) (short form) and a brief description with figures of the 'long form' is given in Barber, Gregory & Marquis, (2020).
The 'short form' of Pachymerium ferrugineum is known from a handful of sites on the coasts of southern England (Dorset to Norfolk). In 2019 the 'long form' was discovered on the Channel Islands.
[The inland records shown on the NBN map (opposite) need verification.]
Both forms are invariably recorded from shingle beaches above the storm drift line, either within shingle or beneath drift wood, often on the landward side on shingle banks.
Interestingly in France the long form is found exclusively on beaches along the Mediterranean and Atlantic coastline, while the 'short form', although still coastal, can also be found along river banks, in woodland, salt marsh, etc.