Available online at www.sciencedirect.com Palaeoworld 19 (2010) 55–74 Research paper Devonian macrovertebrate assemblages and biogeography of East Gondwana (Australasia, Antarctica) Gavin C. Young a,∗ , Carole J. Burrow b,1 , John A. Long a,c , Susan Turner b , Brian Choo a a Research School of Earth Sciences, The Australian National University, Building 47, Daley Road, Canberra, Australian Capital Territory 0200, Australia b Geosciences, Queensland Museum, 122 Gerler Road, Hendra, Brisbane, Queensland 4011, Australia c Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA Received 2 December 2008; received in revised form 27 October 2009; accepted 23 November 2009 Available online 3 December 2009 Abstract The biogeographic significance of Devonian macrovertebrate assemblages from East Gondwana is reviewed, with updates incorporating recent discoveries including new placoderms (antiarchs, groenlandaspid arthrodires, phyllolepids), sarcopterygians (mandageriine tristichopterids, actin- istians, rhizodontids), and actinopterygians. Key taxa are illustrated by new specimens. Empirical patterns indicating range expansion from the area of origin for particular groups are analysed and discussed. The almost complete absence of armoured agnathans from the Devonian of Australia remains one of the most significant differences to Northern Hemisphere deposits, implying an isolating mechanism (oceanic or climatic barrier) between Gondwana and Laurussia during the Silurian–Early Devonian. Increasing faunal exchange with Asia during the Devonian may have been initiated with Pragian–Emsian faunal turnovers in South Chinese assemblages. A Gondwanan pattern in Devonian vertebrates persists into the Frasnian, until the Great Devonian Interchange at or near the Frasnian–Famennian boundary establishes strong Laurussian affinities in the early Famennian, when phyllolepid placoderms first appear in the Northern Hemisphere. New data documented on Early Devonian phyllolepids from Gondwana indicate an extended biostratigraphic range, and a diversity maximum in the Givetian–Frasnian. A late Famennian faunal exchange with Asia is suggested by sinolepid antiarchs, but requires corroboration from other fish groups, with conflicting Laurussian affinities indicated by new sarcopterygian and acanthodian data. An alternative explanation of physiological adaptation within sinolepids is discussed, as is the key question of tetrapod origins, for which the only Devonian examples outside Laurussia occur in Australia and China. The vertebrate biogeographic patterns are completely contrary to palaeogeographic reconstructions based on palaeomagnetic evidence. © 2009 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved. Keywords: Devonian vertebrates; Gondwana; Biostratigraphy; Biogeography; Faunal connections 1. Introduction As already noted by Burrow et al. (2010), the greatest Palaeozoic diversity of vertebrate fossil assemblages from East Gondwana results from the Devonian radiation of the gnathostomes (jawed vertebrates), of which the placoderms (armoured fishes) represent the most diverse group, followed by some groups of lobe-finned bony fishes (sarcopterygians; e.g., dipnoans, osteolepiforms). Acanthodians were common, but are mainly preserved as isolated spines and scales. Both ∗ Corresponding author. Tel.: +61 2 61253446; fax: +61 2 61255544. E-mail addresses: gavin.young@anu.edu.au (G.C. Young), carole.burrow@gmail.com (C.J. Burrow), jlong@nhm.org (J.A. Long), palaeodeadfish@yahoo.com (S. Turner), ozraptor4@hotmail.com (B. Choo). 1 Fax: +61 7 3846 1918. actinopterygians (ray-finned bony fishes) and chondrichthyans (cartilaginous fishes) are present in the oldest Devonian assem- blages in Australia, but remained a minor component until significant radiations in these groups followed the extinction of the placoderms at the Devonian–Carboniferous boundary. Previous summaries of the biogeography of Devonian macrovertebrate faunas were presented by Young et al. (2000) and Young (2003a). Although not as abundant as accumulations of scales, spines and small elements, the evidence of macrover- tebrate remains provides greater information content from complete skeletons, giving many morphological characters such that hypotheses of relationship can be formulated. The stratigraphic and geographic distributions of more inclusive higher taxa within a phylogeny scheme thus provide more com- plex data to interpret the biogeographic history of a particular group (see discussion in Young, 2010). Here, we provide an 1871-174X/$ – see front matter © 2009 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved. doi:10.1016/j.palwor.2009.11.005