Tasmaniosoma and the ER group

(Order Polydesmida, family Dalodesmidae)

This is a taxonomically difficult set of at least 20 H+19 species, of which only one, Tasmaniosoma armatum Verhoeff, 1936, has been well characterised. T. armatum is illustrated above, together with a ventral view of its gonopods (right). Throughout Tasmaniosoma and the ER group, the gonopods are compact and rod-like with a number of curiously shaped processes clustered together at the tip.

I am currently (late 2005) working on Tasmaniosoma and 'ER' and hope to have names for all species by late 2006. Until then they are probably best lumped as 'Tasmaniosoma sp'. A few species are pale gray, but all others are either uniformly reddish or have bright red patches. A number of Tasmaniosoma species have three transverse rows of dome-like bumps on their tergites. The largest are ca. 15 mm long as adults.

I am very interested to see mature males of Tasmaniosoma and will provide code names (e.g. 'ER6') and distribution notes to collectors who need an identification. Please email me to make arrangements.

Species in this set are found in loose litter and under tree bark, and almost never in the soil. They have a distinct preference for eucalypt forest, woodland and scrub, and are found throughout Tasmania. They range from sea level to ca. 900 m. The two species mapped below are interesting because in north central Tasmania their ranges abut along the biogeographical divide known as the Mersey Break (Mesibov 1999).

Localities for T. armatum (red) and Tasmaniosoma sp. 2 (blue). Scale bar = 100 km.
For an interactive map with more up-to-date localities, go to the mapper page.

More information:
 
Taxonomy - Verhoeff (1936)
Distribution, conservation and general - Mesibov (1999), Bonham et al. (2002)