The special issue – Middle Palaeozoic vertebrate biogeography: palaeogeography and climate (IGCP 491) has published recently.

The IGCP Project 491 (Middle Palaeozoic vertebrate biogeography: palaeogeography and climate) is under the UNESCO International Geoscience Program, running from 2003 to 2007 with the co-leaders of IGCP Project 491 Min Zhu (Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences) and Gavin Young (Research School of Earth Sciences, The Australian National University), and the secretary Wenjin Zhao (IVPP). This project held five annual meetings in conjunction with scientific symposia in various participating countries: Riga, Latvia; Gramado, Brazil; Yerevan, Armenia, and St. Petersburg, Russia; Beijing, China, and Uppsala, Sweden. Research associated with IGCP Project 491 has produced over 300 peer-reviewed papers. .

 The contributions brought together in this special issue summarise recent research for some regions where many new vertebrate taxa have been documented in recent years, especially Asia and East Gondwana. Two other contributions provide updated syntheses of the long-studied Devonian vertebrate communities of the Baltic Province. The issue also have more general contributions on atmospheric O₂ levels in the Silurian, palaeomagnetic data and Gondwana–Laurasia interactions, analytical methods in palaeobiogeography, and global analysis of endemism–cosmopolitanism during the Middle-Late Devonian. The remaining papers document new placoderm taxa from North Gondwana, South China and North China, and vertebrate microremains from Uzbekistan.