The Olenelloidea are a superfamily of early Cambrian trilobites, which have been the subject of several phylogenetic analyses and also used to address macroevolutionary questions regarding the nature and timing of the Cambrian radiation. The Sekwi Formation of the Mackenzie Mountains, Northwest Territories, Canada, has yielded numerous species from this clade, and here we present new informatio...

The first complete review of the Carboniferous and Permian trilobite species found within Australia is presented to assess the current standing of Australian taxa in a modern systematic context. The review consists of four families, 20 genera and 61 known species from the early Tournaisian to Moscovian (358.9 Ma to 304 Ma), throughout New South Wales, Tasmania, Western Australia and Queensland....

tribution and more or less evanescent in continuity, to the streams that flowed constantly in one direction and eventually into an unnatural habitat, the sea. They needed a more direct and quicker embryonic development, requiring, it would seem, the abandonment of the nauplius stage. It may therefore well be that the trilobites retaining the nauplius stage did not give rise to these stocks, as ...