*normani (Collinge & Shoebotham, 1909)
Megalothorax minimus is a very common and widespread blind species with a highly characteristic appearance (Figs. 1,2, and 3). Although it is tiny (maximum length 0.5 mm), careful examination of the underside of rotting wood and leaf litter with a hand lens will often reveal specimens walking along with a gait that reminds me of a tiny old man hunched in a baggy coat.
The empodium of the foot is about half as long as the claw (Fig. 4) and the third (ant3) and fourth (ant4) antennal segments are not clearly separate (Fig. 5). The edges of the mucro are smooth (Fig. 6), and the sensory field on the abdomen (Fig. 7) is bordered by five marginal setae (Fig. 8).
There is a single record for Megalothorax incertus, from the ECOTRON experiment at Silwood Park (Naeem et al.,1994). The source of the specimens was not stated, and there is some doubt as to whether Megalothorax incertus is a good species, or is simply a variety of Megalothorax minimus. Bretfeld (1999) reported Megalothorax incertus as being from the dsoutern regions of Europe, and that the characters used to separate the species are variable (extent of serration of the mucro and length of projection at the base of the empodium), as well as difficult to resolve in such tiny springtails (maximum length of 0.5 mm). Even if Megalothorax incertus is shown to be a good species, there is no compelling evidence for including it on the UK/Eire checklist.