PALAEOZOIC TWILIGHT

The Permian crinoids are the last to represent all four Palaeozoic subclasses – the Camerata, Flexibilia, Disparida and Cladida (see Simms & Sevastopulo 1993). With the extinction of 30 families, the Camerata, Flexibilia and Disparida disappeared altogether at or near the end of the Permian in the greatest extinction of all time. This crisis, 245 million years ago, nearly wiped out the crinoids as a whole (Figs. 3 and 61), but, fortunately, some survived to form in the Triassic the stem group of the articulates. Compared with older Palaeozoic systems, crinoids were fairly rare throughout most of the Permian, and assemblages, as described elsewhere in this book, are exceptional. However, because the Permian was a critical time in crinoid existence and evolution, a brief chapter on Permian crinoids is justified.

CLASSIC CRINOID SITES IN TIMOR AND AUSTRALIA

Until World War Two, the most diverse and abundant Permian crinoid fauna known was the one from the Island of Timor in Indonesia. It was discovered, exploited and described by Johannes Wanner in a series of outstanding papers during the first half of the twentieth century. In one of his later monographs Wanner (1937) listed 320 species belonging to 100 genera, most of them new and unique to Timor. The total fauna includes other echinoderms (echinoids and blastoids) as well as gastropods, bivalves, brachiopods and corals. On the basis of the massive skeleton of many of the forms, Wanner concluded that the animals lived in a warm, shallow and partly agitated sea.