A millipede found at an old Welsh coal mine – dubbed the “Maerdy Monster” – is a new species, according to experts.
The bug, found by a naturalist group at the former Maerdy colliery, in Rhondda Cynon Taff, is distinct from the other known groups of millipede species.
Steve Gregory, of the British Myriapod and Isopod Group (BMIG), said the 12mm (0.5in) species is new to science as it is “unknown and undescribed”.
BMIG believe it is the first millipede species found in the UK since 1993.
Mr Gregory said it belonged to the Turdulisoma and Haplobainosomatidae family.
The creatures are usually found across the Iberian Peninsula and it is not known how the millipede came to be in south Wales.
Experts said it could have been accidentally introduced via imported industrial goods.
BMIG said the discovery of a new species in the UK is “very unusual” as “there is not much left to find” because the country has a long history of biological recording by naturalists.
A scientist at the Bavarian State Collection of Zoology research centre in Germany claimed the species was previously unknown and gave the creature the “working title” of the Maerdy Monster.
“The Maerdy species is distinct from the four similar species and, therefore, will have to be formerly described and named as a ‘new species’ in due course,” Mr Gregory told the BBC.
“It is not known whether this is a genuine native species, having colonised after the last Ice Age, or accidentally introduced into south Wales.”
The Maerdy Monster was discovered at the site in December by a group researching spoil tips in an informal event called “BioBlitz”.