Some conservative and some highly-evolved Permian crinoids from eastern Australia

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Abstract
Four dicyclic inadunate crinoids, two poteriocrinoids and two cyathocrinoids, are described from the Permian of eastern Australia. Two new genera, Nowracrinus and Tasmanocrinus, are proposed for the poteriocrinoids N. ornatus (Etheridge), a species formerly assigned to Tribrachyocrinus McCoy, and T. mariensis sp. nov. respectively. Both are highly evolved and possess a combination of features more commonly associated with certain post-Palaeozoic articulates. As a result the genera are difficult to assign to a family and superfamily. The two cyathocrinoids, on the other hand, have retained many features that first appeared as early as the Silurian. They are interpreted as descendants of a crinoid lineage that experienced very little change through the Palaeozoic. On observed characters, the species must be assigned, tentatively at least, to the cyathocrinitid Gissocrinus Angelin, a genus hitherto restricted to the Siluro-Devonian. Only one of the two species, G? voiseyi, is formally named; the other is described as Gissocrinus? sp., pending recovery of more complete material.