Rugose coral diversifications and migrations in the Devonian of Australasia

Abstract

The occurrence of approximately 100 rugose coral genera has been confirmed in the Devonian carbonate dominated successions of Australasia. Their temporal distribution shows that the largest faunal turnovers were in the Pragian and Givetian, with profound extinction events at or near the ends of the Emsian, Givetian and Frasnian. The evolutionary innovation and diversification of the Early Devonian rugose corals of eastern Australia are characterized by a high turnover rate in the late Lochkovian—Pragian and strong dynamism of radiation from late Pragian to medial Emsian, implying considerable dispersal to South China, central Asia and Europe.

After a high intensity of origination in the Pragian, maximum diversity was reached in the Emsian. Phillipsastreids and endophyllids appeared late in the Pragian and became common in the Emsian; stringophyllids appeared in the Emsian. As elements of these families are recorded mainly from the Middle, or even Upper Devonian of other provinces of the Old World Realm, it appears that they may have originated in eastern Australia during the Early Devonian.

Following a marked decrease in generic richness in the Eifelian, faunal diversity reached another high peak in the early mid‐Givetian as a result of immigration of coral genera, probably from South China, central Asia, Europe and northwestern Canada in the Old World Realm.

Keywords:

• Devonian
• Rugosa
• Diversity
• Migrations
• Bio‐event
• Australasia

Notes

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