Pliomerina Chugaeva, 1956

Type species. Pliomera martellii, Reed, 1917, original designation.

Discussion. The type species of Pliomerina is part of Reed’s collection, but this is known only from the cranidium, redescribed here. Silicified and complete material from Australia described by Webby (1971, p. 614) is doubtless congeneric with the Myanmar type species, and provides a fuller diagnosis than is possible from the type material alone. Webby (1971) pointed out that Pliomerina is widely distributed across Australasia and adjacent territories, extending from Kazakhstan in the north to New South Wales, Australia, in the south, with additional occurrences on the South China plate, Sibumasu and Korea, i.e. palaeotropical Gondwana on current palaeocontinental reconstructions. Webby preferred the term “ Pliomerina fauna” to cover this Ordovician biogeographic region to “ Encrinurella fauna” coined by Whittington & Hughes (1972), though they embrace a similar geographic compass. Zhou & Zhen (2008) record the genus through much of the post-Tremadocian Ordovician of China, including northeastern Chinese and Tibetan occurrences.