In their original form, two species of Microbrachius were erected by Mark-Kurik, one from Estonia and one from Belarus.
Microbrachius is a small antiarch genus first discovered in the Middle Devonian (Givetian) Orcadian Basin of Scotland.
Microbrachius sinensis is dated as Eifelian, Middle Devonian and Microbrachius chuandongensis Wang & Zhang, 1999 is dated as Emsian, Early Devonian (see the discussion for more comments on these species).
From the earliest descriptions of Microbrachius it was known that it was an antiarch although a more precise understanding of its phylogeny was not possible until the detailed description of the dermal armour was made by Hemmings (1978).
Suborder BOTHRIOLEPIDOIDEI Miles, 1968 Family MICROBRACHIDAE Gross, 1965 Genus Microbrachius Traquair, 1888
The plate is short, broad and ovoid in shape, being wider than long with a breadth/length index of 120 to 128 (compared with a breadth/length index of 100 to 120 for Microbrachius dicki and around 100 for Microbrachius sinensis and Microbrachius chuandongensis).
Microbrachius kedoae compares well with the type species Microbrachius dicki which was described in detail by Hemmings (1978).
The other Chinese species, Microbrachius chuandongensis was erected on articulated specimens that are not particularly well preserved.
2) correlated the Moroch Beds with the Abava Member of the Burtnieki Formation in Estonia, which also contains remains of Microbrachius sp.
For example, typical Scottish 'endemics' Millerosteus, Watsonosteus and Microbrachius have been found in Estonia, and Actinolepis, common in the Baltic area, is now known from Scotland (Newman & Trewin 2008).
In Scotland Tristichopterus alatus Egerton occurs together with Watsonosteus fletti (Watson) and Microbrachius dicki Traquair in the John o'Groats Sandstone Group (Trewin & Thirlwall 2002, p.
undulata John o'Groats Sandstones, Tristichopterus Eday Flagstones Watsonosteus Microbrachius Upper Caithness Mey Subgroup, Millerosteus Flagstone Group Rousay Flagstone Formation Latheron Subgroup, Ham-Scarfskerry Subgroup, Upper Stromness Flagstones Lower Caithness Achanarras Limestone Coccosteus Flagstone Group Member, Sandwick Fish Bed Rhamphodopsis Robbery Head Subgroup, Coccosteus Lower Stromness Flagstones Lybster Subgroup ESTONIA Reg.