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EVOLUTION AND
BIOGEOGRAPHY
OF AUSTRALASIAN
VERTEBRATES

To give a better idea of the topics covered in this large volume we have provided a more detailed Table of Contents. If you would like more information about a particular chapter then just click on the chapter title.

CHAPTER SUMMARIES

There are no formal abstracts of chapters but the following brief synopses will provide a clearer idea of the topics discussed in each chapter.

Perspectives
(Merrick, J.R, Archer, M., Hickey, G.M and Lee, M.S.Y.)

Initial background summarizes the history of how this book evolved from the original doorstop, introducing some of the major recent developments in both systematics and biogeography.  Then follows a brief illustrated discussion of the boundaries of Australasia and the other geographic sub-regions but emphasizing the focus on the three major land masses of Australia, New Guinea and New Zealand.
          Changed emphases relating to increased knowledge and altered perceptions are outlined and the dominant integrative theme is introduced.  While recognizing that vertebrates (both living and extinct) are only a fraction of biodiversity, it is hoped that by providing a synthesis of the knowledge of Australasian forms, and new techniques, prospects for effective conservation and management of entire living assemblages and environments will be improved.
          Finally, the key individuals who are instrumental in production are acknowledged.

BACKGROUND
Chapter 1. Systematics and the Australasian Vertebrate Fauna
Chapter 2. Environments of the Geological Past
Chapter 3. Evolution of Arid Australia and Consequences for Vertebrates
Chapter 4. The Torresian Connections: Zoogeography of New Guinea
Chapter 5. Drawing the Wallace Line
Chapter 6. Evolution of New Zealand and its Vertebrates

PRIMITIVE VERTEBRATES: FISHES
Chapter 7. Eons of Fishy Fossils
Chapter 8. The Great Devonian Fish Kill at Canowindra
Chapter 9. Marine Fishes of Australia: Zoogeography, Endemics and Conservation
Chapter 10. Australasian Freshwater Fish Faunas: Diversity,Interrelationships, Radiations and Conservation

PRIMITIVE TETRAPODS: AMPHIBIANS
Chapter 11. Origins and Early Radiations of the Amphibians
Chapter 12. The Origins of Australian Frogs
Chapter 13. The Great Frog Decline in Australasia: Causes, Developments and Conservation
Chapter 14. Keys to Families and Genera of Frogs in Australia, New Zealand, New Guinea and Neighbouring Islands

PRIMITIVE AMNIOTES: REPTILES
Chapter 15. Dinosaurs and Other Mesozoic Reptiles of Australasia
Chapter 16. Evolution and Zoogeography of Australian Freshwater Turtles
Chapter 17. Origins and Radiations of Snakes in Australasia
Chapter 18. Evolution and Zoogeography of Australasian Crocodilians
Chapter 19. Australian Lizards – Relationships and Origins
Chapter 20. The Genera of Skinks (Family Scincidae) of Australia and its Island Territories: Diversity, Distribution and Identification

BIRDS
Chapter 21. The Avian Fossil Record of Australia: An Overview
Chapter 22. Australasia’s Bird Fauna Today – Origins and Evolutionary Development
Chapter 23. Island Biogeography: as Illustrated by Birds in the Australasian Region
Chapter 24. Key to the Families of Australasian Birds

MAMMALS
Chapter 25. Origins of Mammals: Morphology, Molecules and a Petrosal or Two
Chapter 26. Furry Egg-layers: Monotreme Relationships and Radiations
Chapter 27. Origins and Early Radiations of Marsupials
Chapter 28. The Australian Marsupial Radiation
Chapter 29. Kangaroos
Chapter 30. Bat Beginnings and Biogeography: the Australasian Record
Chapter 31. Ten Million Years of Rodent Evolution in Australasia: Phylogenetic Evidence and a Speculative Historical Biogeography
Chapter 32. The Australian Dingo
Chapter 33. A Southern Perspective on Cetacean Evolution and Zoogeography
Chapter 34. Humans among Primates
Chapter 35. Combined Keys to Extant Australasian Mammals (McKay, G.M.)

ACCELERATED CHANGE – THE REGIONAL FUTURE
Chapter 36. Molecular Systematics: Implications for Phylogeny, Biogeography and Conservation
Chapter 37. The Role of GIS in Systematic Conservation Planning
Chapter 38. Determining Marine Movements of Australasian Pinnipeds


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 Chapter 1. Systematics and the Australasian Vertebrate Fauna (Lee, M.S.Y.)

          The importance of systematics for conservation and as a unifying theme in biology is introduced, together with the need to be able to organize (sort, categorize, store in an accessible form) the huge amounts of essential data now becoming available.
          As part of the discussion of Phylogenetics both data sources (anatomical, behavioural, ecological, genetic, molecular) and major methods of analysis have to be explained.  Then the question of when to use evolutionary taxonomy and phenetics or cladistics or maximum likelihood is briefly considered, comparing the advantages or limitations of the approaches.  Features of cladograms (summaries of results of phylogenetic analyses) are outlined and the concepts of mono-, para- and polyphyletic groups explained.
          The hierarchy and mechanism of the Linnaean system of classification is summarized and its disadvantages (arbitrary distinctions, subjectivity, inconsistency) demonstrated, before the new more rigorous phylogenetic taxonomic system (designated Phyllocode) is introduced.  The basic definitions for naming clades are given with examples and a cladogram summarizing relationships of all clades covered in this volume is provided.  Finally, continuing controversies and the dynamic nature of current systematics are emphasized.


Chapter 2. Environments of the Geological Past
(White, M.E.)

          The main aim of this chapter is to show how basic physical and chemical processes shape new environments which interact with organisms present and, through natural selection, influence evolution.  Although the origins of life and principal geological processes are briefly discussed, it is the events of the Phanerozoic Eon that are considered in detail, and the crucial role of plants is emphasized.  While general comments are included on significant global processes the focus is on the Australian continent.
          The palaeogeography of the Australian region in successive geological periods, from the Cambrian to the present, is illustrated by a series of maps.  Comments on major climatic fluctuations, habitat changes and plant groups present are included; dominant faunal components – especially local vertebrates – are also listed.  Representations of typical landscapes are incorporated for interest.  The better-documented Tertiary Period is discussed in more detail – epoch by epoch – to demonstrate the later changes and fluctuations that continued into the Quaternary.  The extreme Pleistocene Ice Age conditions are described and the relatively recent origin of modern ecosystems is noted.


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Chapter 3. Evolution of Arid Australia and Consequences for Vertebrates
(Dawson, T.J. and Dawson, L.)

          The poor record of late Cretaceous to early Tertiary times is contrasted with the recently expanded data for the past 25 million years and impacts of two major episodes of climatic change, since late Oligocene, are briefly described.  Late Miocene extinctions of mammals are discussed and the development of grazing explained.
          Moderate climates for much of the Pliocene were followed by substantial changes in early to mid-Pleistocene, with further dramatic cyclic climatic swings in late Pleistocene.  Although details are unclear the onset of extreme aridity is also associated with a megafaunal extinction.
          The consequences of this aridity for vertebrates are considered first in terms of basic constraints (e.g. water, food, temperature) for life in the arid zone and then as adaptive strategies.  Mechanisms in each of the five main groups (such as aestivation, burrowing, cleidoic egg, dietary specialization) are discussed with emphasis on energetics (weight/surface area, heat exchange).  The mammals are considered in most detail and the benefits of large size (relating to utilization of food sources, thermoregulation, locomotion) are outlined in the final section.


Chapter 4. The Torresian Connections: Zoogeography of New Guinea
(Heinsohn, T. and Hope, G.)

          The longstanding land-bridge in the Pleistocene between Australia and New Guinea and the relatively recent origins of this continental island are emphasized.  The main biogeographic subregions are briefly discussed before the diversity of the terrestrial vertebrate groups is considered. Then the major factors contributing to the peculiar zoogeography of New Guinea are considered.
          Firstly, the meganesian inheritance of southern Gondwanan biotas and long-distance colonizers is explained, then habitat diversification is described in more detail.  The gradients and barriers observed are discussed in terms of distinct climatic zones and local geologic as well as geomorphic processes.  Topographic controls are largely related to the central mountain range and examples of the associated altitudinal and bioclimatic zonations are provided.  The third factor is the role of New Guinean highlands as a refuge for Gondwanan forms from the increasing aridity of the Australian mainland.  The Pleistocene fluctuations (temperatures, sea levels) must also be taken into account – both enhancing exchange and increasing isolation in some areas.
          The main influences on the recent development of New Guinean biodiversity and niche utilization are briefly outlined, before examples of evolutionary convergence from a limited founding stock are provided.  Finally, the five principal means by which humans have influenced zoogeography are discussed; the meagre data currently available and potential for new discoveries are emphasized.


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Chapter 5. Drawing the Wallace Line
(van Oosterzee, P.)

          Initially biogeography is defined and the development of this aspect of science by Alfred Wallace is briefly outlined.  Extensive field studies in the Amazon and Indonesia led firstly to his proposal of the Sarawak Law and then of natural selection as a mechanism for evolution.
          The evidence for a faunal boundary (now known as the Wallace Line) is summarized on the basis of observations by Wallace as well as later zoologists, and the unusual nature of this zone separating provinces is emphasized.  Wallace’s explanation of this boundary integrated, for the first time, both the evolution of the species and geological history of the region.
          The complex tectonic and climatic processes now known to have occurred in the Indonesia-New Guinea region are then briefly described.  Cicadas are used as a model group to demonstrate biogeographic principles, both in relation to the Wallace line and elsewhere.  Finally the differences between continental and oceanic island faunas are discussed, in relation to particular areas adjacent to the Wallace Line.  The accidental, haphazard colonization or human factors that may contribute to apparently anomalous distribution patterns now are discussed.


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Chapter 6. Evolution of New Zealand and its Vertebrates
(Holdaway, R.N. and Worthy, T.H.)

          After an introduction to the geological history, formation and current geography of New Zealand the authors provide summaries of the diversity of extant terrestrial and freshwater vertebrate faunas.  Fossil remains for the small fish and amphibian faunas are briefly discussed, together with the more extensive reptile fauna.  The fragmentary fossil record demonstrates that New Zealand had a diverse group of dinosaurs in the late Cretaceous.
          The bird fauna dominates and is discussed in more detail with numbers of indigenous breeding species, levels of endemism and extinctions considered.  Several species of bat are the only native mammals – their relationships are explained, in terms of Tertiary geological and climatic change.
          Several groups of the original vertebrate fauna (leiopelmatid frogs, sphenodontids, moa, primitive passerines) are identified and implications of the dramatic reduction in terrestrial habitats, caused by Oligocene marine transgressions, are emphasized.  Although the late Tertiary record is sparse it suggests considerable faunal turnover, but late Pleistocene-Holocene material is extensive and shows a massive extinction event in the last 2000 years.  The flightless feature among disparate bird groups, naivety resulting from an absence of mammalian predators and life cycle strategies based on k-selection, as well as humans, are all discussed as factors contributing to extinction.  Human impacts are broadly divided into predation influences and environmental modification – especially in relation to introduced mammals.
          Then the situation relating to endangered birds is considered with summary tables.  Finally the historic and current importance of islands, in the conservation of native vertebrate faunas, is explained – both for the maintenance of relict populations as well as establishment of new protected populations in isolated ecosystems.


PRIMITIVE VERTEBRATES: FISHES

Chapter 7. Eons of Fishy Fossils
(Basden, A.M, Trinajstic, K.M and Merrick, J.R.)

          After emphasizing the long evolutionary history of fishes and the enormous diversity of fish fossil remains, the initial focus is on Taemas Formation and Buchan Group limestones in south-eastern Australia.  The Devonian fish faunas are described and conodonts are discussed in terms of structure, relationships and their use in precise dating.  Findings of other eastern studies are compared before features of the recently described osteichthyan braincase (from Wee Jasper ) are analysed together with possible links.
          Then the biogeography and biocorrelation of microvertebrate remains from Western Australia is considered.  The diversity of Gneudna Formation fishes is compared to the Gogo Formation.  Problems of identifying microvertebrate remains are explained and the use of thelodont, chondrichthyan and acanthodian scales for biocorrelation is demonstrated.  Biogeographic relationships are then discussed, taking the estimated late Devonian positions of Gondwanan land masses into account together with common faunal elements.  Finally the development of teleosts in the Mesozoic is briefly outlined; the fragmentary Cainozoic record for most groups is emphasized and longevity of select extant groups demonstrated.


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Chapter 8. The Great Devonian Fish Kill at Canowindra
(Ritchie, A.)

          The chance discovery (in 1956) of one of the most remarkable fossil beds in Australia is briefly outlined, together with some long-term detective work by the author.  Studies on the huge amount of material recovered in 1993 are described with comments on diversity and systematics, population structure and local conditions in the Devonian (~360 m.y.a.).
          The evidence indicates that, under severe drought conditions, many thousands of fish (of all sizes) were trapped and killed in a drying lake or waterhole.  The bodies were rapidly covered with fine sand, before carcasses disintegrated, resulting in remarkable preservation.  Although the fauna was dominated (in numbers) by 2 types of antiarch placoderms, another arthrodire and several genera of large sarcopterygians (including lungfishes) were also present.  These taxa are described (with illustrations) and their relationships discussed.
          Although not evenly distributed it appears that one of the antiarchs was present in both adult and juvenile sizes whereas the other was mainly present in larger sizes.  Interpretation problems created by tectonic deformation of remains are explained and new techniques for correction briefly outlined.  The Canowindra assemblage is compared with other Devonian faunas and palaeoecological considerations discussed.


Chapter 9. Marine Fishes of Australia: Zoogeography, Endemics and Conservation
(Paxton, J.R., Allen, G.R., and Hoese, D.F.)

          After initially outlining major historical studies documenting the total diversity of Australian marine fish faunas and discussing them by areas or habitats – the authors focus on coral reef fishes.  Fish faunas of Australian reef habitat are compared with coral reefs of other selected areas of the Australasian region.  Comparisons of most speciose families and regional distributions are included; then areas and groups (families, species) of endemism are identified.
          Conservation problems of marine fishes are then considered with emphasis on overfishing, habitat degradation and exotic introductions.  The special situation relating to seamounts is discussed and the concept of Marine Protected Areas is explained.  It is concluded that insufficient data on fish communities below 50 m depth, preclude any detailed analyses of biogeography or faunal boundaries as yet.


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Chapter 10. Australasian Freshwater Fish Faunas: Diversity, Interrelationships, Radiations and Conservation
(Merrick, J.R.)

          Australasian freshwater fish faunas are depauperate but diverse – both in morphology and origin.  Very few primary species are represented, some common Asian families are absent but other families have radiated extensively in Australasian freshwaters.  The familial key highlights the morphological variation and diversity within Australasian freshwater ichthyofaunas.  Only two families (each represented by a single genus) are common to all three regions and two families have freshwater representatives only in New Zealand.  Of the 126 genera represented, 53 are common to New Guinea and Australia.  Over 480 species from 45 families are currently recognized and many species occur both in northern Australia and New Guinea – each of these faunas exceeds 200 species.
          Major events or processes affecting speciation and distributions of Australasian freshwater fishes include: the pre-Tertiary detachment of New Zealand and early Tertiary splitting of Australia from Gondwana; the opening of the Tasman Sea and formation of island groups; the position of the Indian subcontinent; the late Miocene marine regression; the more recent emergence of New Guinea, with dramatic Pliocene uplift, periodic cutting of Sahul Shelf land-bridges.
          Although interrelationships of early teleosts are still uncertain, it is clear that origins of some extant groups extend back to the early Tertiary.  Familial endemism is low, but generic and specific endemism is significant.  The influences of geographic barriers on ranges are considered and known zoogeographic patterns summarized in terms of current bioregion concepts. Several major long-term radiations are briefly described and factors contributing to recent rapid speciations are also discussed.
          Recent short-term radiations of introduced species are briefly outlined before the conservation status of faunas is discussed together with the need for integrative system-based management strategies.


PRIMITIVE TETRAPODS: AMPHIBIANS

Chapter 11. Origins and Early Radiations of the Amphibians
(Warren, A.)

          Tetrapod origins from Osteolepiform fishes are briefly outlined and major tetrapod characters listed.  The controversy concerning the relationships of the major groups of extinct and extant tetrapods that have been considered as amphibians is briefly summarized before focusing on the extinct anamniote tetrapods – especially the temnospondyls – not closely related to the Lissamphibia.
          After briefly outlining the occurrence of the earliest tetrapods, the Australian record is discussed chronologically under four geological periods from the Devonian.  The unusual embolomere features of the Carboniferous Ducabrook material are contrasted with the Temnospondyli radiation, which commenced in the Permian and preceded Mesozoic development of the Stereospondyli.  Discussion of the diverse Triassic assemblages is divided into five Basin faunas.
          The recent discovery of post-Triassic stereospondyls is noted with the genus Koolasuchus surviving to the early Cretaceous.  As tetrapods first appeared in several continents at similar times the site of origin is not yet known; however, it is clear that they originated before late Devonian and that invasion of the land occurred during early Carboniferous.  The later radiation of stereospondyls is thought to have commenced in eastern Gondwana.


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Chapter 12. The Origins of Australian Frogs
(Tyler, M.J. and Lee, M.S.Y.)

          This short chapter briefly summarizes the diversity of the extant frog fauna and then reviews the accepted models for development of the  Australian herpetofauna. The discussion focuses on how the major lineages could have colonized Australia. The options for source stocks (Gondwana, intrinsic derivation, Asia) are considered and the implications of recent fossil finds discussed.  Finally, the inconsistencies between existing records and accepted concepts are identified; it is suggested that the dual origin model for Australian frogs needs further verification and details of endemic radiations should be reviewed.


Chapter 13. The Great Frog Decline in Australasia: Causes, Developments and Conservation
(Richards, S.J., Alford, R.A. and Bradfield, K.S.)

          The authors initially outline the current situation, explaining the focus on Australia with a description of factors that have contributed to altered emphases in research.  A table summary of local frogs that have experienced significant declines and postulated causes is provided.
          Current research initiatives are discussed under broad headings, with consideration of the impacts of UV-B radiation followed by comments on disease (variable incidence and virulence, apparent emergence of infectious conditions) and interactions with other species – especially exotic predators; the susceptibility of larvae which have not evolved appropriate avoidance mechanisms to introduced predators is emphasized.  Documented impacts of pollutants are listed and select reports of mass mortalities are outlined.
          The evidence indicating real population declines, rather than natural population fluctuations, is briefly reviewed.  Examples of long-term monitoring programmes are described and the use of developmental stability analysis, as a rapid early-warning of population decline, is discussed.  Contingency strategies, in the form of animal husbandry and assisted reproductive technologies, are considered; although clearly useful as part of conservation plans these techniques have a number of limitations.  Areas requiring priority research include: details of specific ranges, abundance and habitat requirements as well as interactions between species and populations and diseases.


Chapter 14. Keys to Families and Genera of Frogs in Australia, New Zealand, New Guinea and Neighbouring Islands
(White, A.W.)

          The diversity of current Australasian frog faunas is demonstrated by illustrated keys.  This group of amphibians (including about 300 species) has a high level of endemism and is represented by at least 37 genera in 6 families (5 native, 1 introduced).  The dichotomous keys (based on skeletal and other morphological features) distinguish most taxa to generic level; brief notes about ranges are also included and poorly known groups identified.


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PRIMITIVE AMNIOTES: REPTILES

Chapter 15. Dinosaurs and Other Mesozoic Reptiles of Australasia (Scanlon, J.D.)

          The main focus is on the biological features of major dinosaurian lineages and their history in the Australasian region, based on limited body fossils and trackways.  The unusual and fluctuating climatic conditions at the end of Permian and during Triassic times are explained, but the diversity of the traces of Triassic terrestrial faunas is emphasized.
          The earliest dinosaurs are briefly discussed before the bipedal predatory theropods are considered; both ceratosaurian and coelurosaurian lineages are described with the evidence for Cretaceous local bird-like forms presented.  Then the limited and fragmentary remains of the long-necked giant sauropod forms are considered before a more detailed discussion of several groups of the Ornithischia (‘bird-hipped’ beaked herbivores).  The first thyreophorans (armoured quadripeds) known from Australasia are from mid-Jurassic times, whereas the ornithopod lineage dates from early Jurassic deposits in Queensland; some of these diverse bipedal browsers show adaptations for extreme (cold) environments.  The Marginocephalia are unknown before the Cretaceous and include two lineages (pachycephalosaurs, ceratopsians) of spiky-headed herbivores.
          The final part of the chapter treats the euryapsid marine reptiles which were contemporaneous in the Mesozoic.  Ichthyosaurs have a long but fragmentary record in this region from the early Triassic; plesiosaurs and related forms were abundant and diverse during the Cretaceous in both Australia and New Zealand.


Chapter 16. Evolution and Zoogeography of Australian Freshwater Turtles
(Georges, A. and Thomson, S.)

          Initially turtle diversity (world-wide) is summarized and success considered in terms of variations on a unique body plan.  Turtle origins are related to select fossils and key characteristics.  The focus then narrows to Australasian faunas.  The limited diversity of extant forms (mostly Chelidae), and the current state of taxonomic flux , is contrasted with extinct faunas.  Although poorly known the fossil taxa were clearly more diverse and this introduces discussion of origins of extant species.
Controversies over relationships of existing freshwater turtles are discussed and hypotheses to explain the current distributions of Australian species are suggested.  In northern Australia major factors influencing zoogeographic patterns are considered to be Quaternary aridity associated with land-bridges and lake formation in the Gulf of Carpentaria.  In the south-east the primary driving force appears to be climatic.


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Chapter 17. Origins and Radiations of Snakes in Australasia
(Scanlon, J.D.)

The distinct Australasian snake fauna is explained in terms of extensive radiations (since Oligocene), of blind snakes, pythons and venomous elapids; the presence of lineages such as burrowing snakes, boas or filesnakes and absence of vipers or pit-vipers.  While substantial controversy remains about the influences and timing of invasions into Australia, consideration of fossils and recent cladistic analyses suggest that snakes originated in the Cretaceous as relatively large predators, closely related to marine varanoid lizards.
          The long fossil record and diversity of the recently extinct Madtsoiid group is described, before several families of worm-snakes (Scolecophidia) are discussed.  Multiple recent invasions are suggested as only limited radiation has occurred.  The more diverse sister-group, Alethinophidia, including more familiar taxa (pythons, tree-snakes, venomous elapids) are then considered and the biogeographic puzzle posed by the distribution of boas is explained.  Among the caenophidians the aquatic Acrochordidae are discussed in more detail.
          The elapid radiation has resulted in over 100 species being recognized, which represent about 30 genera; however, recent phylogenetic analyses (based on DNA) refute the hypothesis of a Gondwanan origin for the group.


Chapter 18. Evolution and Zoogeography of Australasian Crocodilians
(Willis, P.M.A.)

          The introductory background summarizes the diagnostic features of crocodilians, provides a brief history of the group and explains that two extant Crocodylus species in Australia and New Guinea are relatively well-documented; however, it has only been in the last two decades that research has revealed the presence of diverse fossil crocodilian faunas in many parts of Australia since the Cretaceous Period.
          After briefly describing the major, but fragmentary, Cretaceous remains the author goes on to discuss Tertiary and Quaternary crocodiles in more detail; results of research on fossils of ten genera are summarized.  Then the Australian Tertiary radiation, cladistic analyses and mekosuchine characters are briefly considered in a review of phylogenetic relationships.
          Zoogeographic patterns of mekosuchinid remains are discussed in terms of tectonic movements, land-bridges, isolation, regional habitat utilization, competition and other ecological changes.  Finally, the concept of ecomorphic diversity (in size and head-shape) is introduced, in relation to differential resource usage in these fossil faunas.


Chapter 19. Australian Lizards – Relationships and Origins (Hutchinson, M.N. and Smith, S.A.)

          Within the reptilian assemblage the relative success of the order Squamata (lizards and snakes) is briefly outlined in terms of diversity.  Although lizards are acknowledged as paraphyletic (four distinct lineages) they are treated as a single grouping – following convention.  The conservative nature of lizard anatomy and biology is emphasized and the unique characteristics that define squamates are divided into three categories (skull anatomy, teeth, postcranial features) for discussion.
          The poor squamate fossil record is summarized, from the earliest Jurassic remains to three of the major groups still represented in the extant fauna (Iguania, Scincomorpha, Anguinomorpha).  The importance of molecular techniques in helping to elucidate origins and relationships within taxa are then considered in detail; molecular comparisons have indicated where sister lineages of Australian radiations may be found and, further, provided estimates of times when Australian taxa diverged from sister lineages.  Summary phylograms for squamates, agamids, gekkonids, scincids and varanoids are presented; finally several unresolved issues, relating to both geckoes and the large skink radiation, are identified for future study.


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Chapter 20. The Genera of Skinks (Family Scincidae) of Australia and its Island Territories: Diversity, Distribution and Identification
(Couper, P.J., Covacevich, J.A., Amey, A.P. and Baker, A.M.)

          Recent revisionary studies of this group are briefly discussed but it is emphasized that interrelationships of Australian skinks remain unclear.  Differences in digitation and variation in other features are used to demonstrate taxonomic problems or anomalies; abbreviated taxonomic histories of genera are provided.
          Two updated, illustrated keys to Australian genera (based on digital formula differences) have been developed, together with distribution maps of total generic ranges.  A summary list of currently recognized species of Australian skinks is included.  General diversity and distribution patterns are then considered with brief notes on conservation status.


BIRDS

Chapter 21. The Avian Fossil Record of Australia: An Overview (Boles, W.E.)

          Building on very detailed reviews, by other authors some years ago, this summary article updates aspects of current knowledge with emphasis on more recent studies.  Although patchy, the Australian fossil bird record is richer and longer than that of other regional land masses.  Commencing with the earliest Cretaceous remains, the Australian fossils are discussed chronologically (by geological period or epoch) with emphasis on the rich, diverse faunas in late Oligocene to mid-Miocene times and in late Quaternary deposits.  The record is summarized in tabular form and shows a strong bias towards certain taxonomic groups, especially in the Tertiary.
          Major Australian localities that have produced fossil birds and geologic ranges of major groups are illustrated in figures.  Dispersal routes and distribution patterns of select groups are considered, but it is clear that modern distributions do not reflect those of the past.
          The evidence for a southern origin of songbirds (Passerines) is briefly discussed, as well as the origins and relationships of major groups of flightless forms.  Factors such as climatic shifts, habitat changes, competition and predation are considered as contributing to local Pleistocene extinctions.  Finally ancestor-descendent and morphological diversity patterns within lineages are assessed.


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Chapter 22. Australasia’s Bird Fauna Today – Origins and Evolutionary Development
(Schodde, R.)

          After a brief introduction to the rich regional avifauna (~ 1300 species), in terms of its ecological and faunistic characteristics, this large chapter focuses on the origins and evolution of extant birds.
          The traditional theories of how ancestral stocks arrived in a series of waves from Eurasia are discussed, in relation to two main pathways and vegetation types.  The problems for these hypotheses, of continental drift, variable dispersal capacities and current zoogeographic patterns are explained.  The patchy fossil evidence is reviewed emphasising the shared Gondwanan elements and the importance of passerines, before molecular evidence is considered.  DNA hybridization, electrophoretic studies and other techniques have clarified relationships within Australasian stocks and suggested ancestral sources.
          Then evolutionary developments since the mid-Tertiary (~30 m.y.a.) are summarized.  Traditional approaches (region by region) are discussed with more recent holistic concepts (which take the Australia- New Guinea connection into account).  Initially events in the later Tertiary are related to waterbirds and then the development of New Guinea, with Tumbunan and Irian avifaunulas, is considered; followed by detailed descriptions of the development of the Bassian, Torresian and Eyrean avifaunulas.
          The Quaternary radiations are described in terms of glaciation cycles, altered biotic zones and the stimulus for speciation in younger derived avifaunulas.  The disharmonic New Zealand assemblage is discussed, then features of the geographic sections of both the Tumbunan and Irian avifaunulas are listed.  The Arafura Platform and emergence of a mangrove avifauna is considered, before the Torresian, Bassian and Eyrean avifaunulas are discussed in further detail – in terms of local geographic sectors, refugia, barriers.  Finally a few comments about migrants and opportunists are included.


Chapter 23. Island Biogeography: as Illustrated by Birds in the Australasian Region
(Ford, H.A.)

          After outlining why islands are of special interest to biologists (unique biotas, simple isolated ecosystems), the major processes (volcanism, sea level changes, continental fragmentation) that give rise to islands are briefly reviewed.  Dispersal mechanisms by which organisms reach and colonize islands are then discussed, with a focus on examples of bird faunas in the Australo-Pacific region.  General points of the Theory of Island Biogeography are introduced and interactions within island communities explained.
          Evolutionary changes (specializations, altered ecological niches, differential genetic drift) documented on islands are summarized. Processes contributing to local extinctions are then illustrated with examples of bird species in Australia, New Zealand, Polynesia and the Hawaiian Islands.
          The application of the Theory of Island Biogeography to conservation in general, in terms of isolated patches of environment, is considered and the advantages of large areas (retention of biodiversity), circular shape (maximal core area, minimal edge effects) with linking corridors to adjacent reserves are emphasized. The apparent weaknesses of the theory are outlined and the advantages of a whole landscape approach are explained. The concepts are compared with conservation practice in Australia, particularly to bird faunas in the Mount Lofty Ranges.  Finally the controversy concerning the relative benefits of corridors is briefly discussed.


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Chapter 24. Key to the Families of Australasian Birds
(Boles, W.E.)

          The diversity of the extant Australasian bird faunas is demonstrated by an illustrated key.  This dichotomous key has been designed to allow identification (of adults only), to family level for non-passerines and ordinal level for passerines---using external field characters; the taxonomic coverage is all families of non-passerine birds (including introduced species) and the order Passeriformes.


MAMMALS

Chapter 25. Origins of Mammals: Morphology, Molecules and a Petrosal or Two
(Johanson, Z.)

          The definition and diagnosis of the main groups to be included in Mammalia is complicated by non-preservation of some characters in a fragmentary fossil record and the identification of synapomorphies.  The obvious problems of relying solely on morphological features have resulted in attempts to re-define Mammalia on the basis of common ancestry.  With emphasis on the Mammaliamorpha grouping, a short list of taxa used in recent phylogenetic analyses of mammalian relationships are then discussed; notes on the dental evolution are incorporated in these considerations.
          The trends in usage and suite of characteristics currently used to distinguish mammals (in higher-level analyses) are then discussed in more detail.  The range of character systems include dental morphology, sidewall of the cranium, postcranial features and (more recently) basicranial features, such as the robust petrosal bone.  Then the increasing use of molecular analyses, to estimate timing of origin of mammalian groups, is outlined; acknowledging potential errors relating to differential rates of change and calibration dates the molecular results are contrasted with current fossil evidence.
          The final section of the chapter relates to whether the origins of the Mammalia can be traced to a particular geographic region; the limited evidence suggests the Northern Hemisphere in late Triassic.  But Australia appears to be important in the development and radiations of some more derived mammals in the Cretaceous and Tertiary.


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Chapter 26. Furry Egg-layers: Monotreme Relationships and Radiations
(Musser, A.M.).

          After outlining the scientific confusion, caused by this paradoxical group, and explaining the origins of the term ‘monotremes’ the structure, physiology, genetics and life histories of extant species are considered.
          The surviving ornithorhynchid is viewed as plesiomorphic; its range and curious mixture of anatomical features is described, before the bill structure and its sensory capacities are discussed in more detail.  The distinct echidna features and apparent morphological convergence in the group are then considered; recent systematic studies on New Guinean Zaglossus are summarized.
          Overall monotreme structure is considered in more detail under three main categories.  The primitive skull features and specializations are explained before components of the postcranial skeleton (e.g. vertebral column, shoulder girdle) are compared; features of the soft anatomy and physiology are also discussed.  The reproductive system (anatomy, hatching, suckling) is described with comments on body temperature, brain structure and musculature.
          The monotreme fossil record is divided into several sections; the fragmentary Mesozoic (Cretaceous) forms are discussed before the true platypuses (from Tertiary) are considered, through to Holocene.  The few pre-Pleistocene tachyglossids are briefly listed before the more extensive Pleistocene material is discussed in detail.
          Monotreme biogeography can be explained in terms of timing and sequence of separation of Gondwanan components as well as climates and dispersal routes in suitable habitat zones, followed by isolation in Australasia.
          The relationships of monotremes are discussed at 2 levels--within Monotremata and with other mammals; the controversy over the exact affinities of monotremes to other mammalian groups is briefly summarized.  The limited evidence for a southern (Gondwanan) origin and radiation of monotreme ancestors is outlined and, finally, the major evolutionary trends displayed in the group are briefly discussed.


Chapter 27. Origins and Early Radiations of Marsupials
(Wroe, S. and Archer, M.)

          Firstly, the problems of defining marsupials and comparative cladistic analyses of mammalian taxa are outlined.  Discussion then focuses on 11 potentially derived characters as they relate to all known marsupial and related taxa.  It is concluded that only three of the original features appear to be useful, but additional synapomorphies demonstrated by recent studies are summarized.
          Next the controversy over the oldest marsupial and area of origin is considered.  The difficulties of interpretation and relationships of groups like Deltatheroidea are explained, but it is suggested the earliest marsupials possibly arose in North America or Asia in early Cretaceous times.
          Several late Cretaceous deltatheroidan taxa from Asia are briefly described, but the majority of marsupials from this period are from North America.  These include the Pediomyidae, thought to include forms ancestral to later groups found in Australia; however, it is clear that South America’s abundant marsupial faunas came from North America.  Diverse South American faunas are known from earliest Tertiary times.
          The relative diversity of southern marsupial faunas in the Tertiary is briefly discussed, including key points such as: South American faunas comprised 7 superfamilies and filled insectivore, omnivore and carnivore roles; Australian faunas comprised 9 superfamilies and dominated all terrestrial mammalian niches; most South American species became extinct in the Pliocene, although a number of taxa are linked with Antarctic and Australian radiations.
          Dispersal had occurred by middle Eocene form South America to Antarctica, where three taxa have been described.  Further movement from Antarctica to Australia was possible up to 64 m.y.a., being progressively restricted after that time, with some links remaining until 38 m.y.a.  The earliest Australian marsupial fossils (at Murgon) are dated at 55 m.y.a., but relationships between Murgon taxa and the rest of the Australian marsupial radiation are yet to be demonstrated.


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Chapter 28. The Australian Marsupial Radiation
(Archer, M. and Hand, S.J.)

          This chapter focuses on the development of diverse marsupial groups in Australia during the Tertiary, when the continent was relatively isolated from other land masses. The patchy fossil record is briefly summarized and the diversity discussion commences with the dasyuromorphians including dasyurids, numbats and thylacines; the latter are considered in some detail because of interest in the recent extinction of the Tasmanian tiger and attempts to re-create its genome. Then bandicoots and bilbies are considered together with the poorly known moles and strange extinct forms such as ‘thingodontans.’
          The large diprotodontid order is divided into the wombat-like forms, the gigantic extinct diprotodons and other groups such as the fascinating thylacoleonid lions.  These sections include comments on some of the less obvious ecological implications of the diprotodont extinctions and hypotheses on how thylacoleonids hunted and killed prey.
          In the last part of the chapter the phalangeridans (possums and kangaroos) are reviewed. Most of this discussion relates to the various groups of possums, both living and extinct forms, with a few final comments on kangaroos – referring readers to the following chapter on that group. The possums are broadly divided into four categories (Burramyoidea, Phalangeroidea, tarsipedioids, petauroids) with comments on relationships, recent discoveries, behaviour and zoogeographic patterns.


Chapter 29. Kangaroos
(Cooke, B)

          The introduction uses selected historical reports to demonstrate how puzzling, but useful, these marsupials were to early explorers.
          The diversity of kangaroos and closely related groups (both living and extinct) is then discussed in terms of characteristics such as: feet (and a bipedal hopping gait); dentition; head musculature and cranial features; as well as differences in stomach structure.  Some four potoroid subfamilies and three macropodid subfamilies are considered – including forms from both Australia and New Zealand.
          Comparative morphological findings are then synthesized as a number of phylogenetic schemes are contrasted.  More recent studies using cytological, immunological, allozyme and molecular (DNA) data are also included.  The formation of several clades is postulated, but the phylogeny of the group is still confused, pending discovery of early Oligocene or late Eocene fossils.


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Chapter 30. Bat Beginnings and Biogeography: the Australasian Record
(Hand, S.J.)

          Initially the diversity of extant bats (megachiropterans, microchiropterans) is emphasized and aspects of diet and biology are introduced, including sensory capacities and migratory patterns.  This is followed by discussion of some of the hundreds of fossil bat species known from deposits since the Early Eocene.  Phylogenetic relationships are considered and a Southern Hemisphere origin for modern bats is suggested.
          Discussion then focuses on the Australian record (90 species recognized) with sections on nine families (2 of these groupings are fossil).  Endemism is relatively low and the taxonomy of some living forms is poorly understood.  Although there is a gap, between 55-26 m.y.a., the Australian fossil bat record is one of the world’s oldest and best; the important relatively recent discoveries at Murgon and Riversleigh are described.  Finally it is concluded that the Australian fossil bat fauna consists of several components including: archaic cosmopolitan groups; relatives of extinct and extant species; ancestors or close relatives of extant Australian taxa.


Chapter 31. Ten Million Years of Rodent Evolution in Australasia: Phylogenetic Evidence and a Speculative Historical Biogeography
(Aplin, K.P.)  

          An overview of rodent evolution in the Australasian region is presented, integrating the available evidence from karyology, immunology, genetics, palaeontology and the morphology of the skull and teeth, spermatozoan and male reproductive anatomy. The diverse lines of evidence converge to produce a reasonably consistent and well-resolved picture of rodent evolution in the region, and critical use of the ‘molecular clock’ derived from albumin immunology provides some realistic estimates of the timing of cladogenic events.
          Consideration of the regional palaeogeographic setting, including the long-term history of global sea level change, provides the context for a speculative historical biogeography for Australasian rodents. This hypothesis postulates an early entry of rodents into New Guinea, (~ 7--9 m.y.a.) followed by a later invasion of Australia by an ancestral ‘conilurin’ around 5--6 m.y.a. At least ten rodent taxa have crossed the Torresian barrier during the course of the Pleistocene, the majority moving from New Guinea to Australia. Several of these taxa have proven highly successful, dispersing widely to occupy many new habitats. The biogeographic conclusions of the study highlight the rapidly changing face of the Australian biota over the last few million years, and clearly underscore the importance of New Guinea as a location of significant mammalian evolution during the late Tertiary and Quaternary.


Chapter 32. The Australian Dingo
(Corbett, L.)

          After a brief introduction to dog ancestry, and the contrasting conclusions from studies using molecular versus skeletal features, the origins of the Australian dingo (Canis lupus dingo) and its first arrival in Australia (~ 4000 years BP) are considered.  Dates and locations of dingo fossils are summarized and the rate of continental radiation briefly discussed, in relation to regional Holocene climates or geographic events as well as modern ecological data.
          The close interactions between dingoes and Aborigines are explained in detail and then the fluctuations in dingo abundance, since European settlement, are described together with the effects of control techniques.  The ecological roles of dingoes are then discussed in terms of interactions with other predators, such as the thylacine and Tasmanian devil, and adaptable pack behaviour.  Significant impacts of dingo predation on other fauna appear to relate to abnormal conditions such as drought or intense widespread bushfires.
          Finally, it is emphasized that the major threat to the survival of dingos is hybridization with domestic dogs.  Conservation strategies recommended include identification of pure dingo stocks, using molecular techniques; establishment of island refugia; establishment of large mainland sanctuaries.


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Chapter 33. A Southern Perspective on Cetacean Evolution and Zoogeography
(Fordyce, R.E.)

          After a brief introduction to cetacean diversity and the special problems of working on this group, selected key publications in recent years are listed for background reference.  Discussion then focuses on taxonomic patterns, reviewing the Australasian record at family level.  The section on the clade Cetacea explains the present understanding of cladistic relationships with more detailed considerations of archaeocetes, the mysticetes and odontocetes---with an emphasis on the dolphins.
          The Australasian stratigraphic record and localities are then reviewed, suggesting both a diverse fossil assemblage and utilization of both fluviatile and marine habitats; the richness of remains in New Zealand limestones and greensands is emphasized.
          Analysing cetacean systematics reveals three types of patterns.  First, examination of distributions of extant forms shows that many species have antitropical or bipolar patterns – with sister-taxa present in each hemisphere but not in the tropics; others have tropical/temperate ranges and a few are cosmopolitan.  Second, diversity or disparity among living species has been noted in feeding apparatus, food preferences and use of feeding grounds; but these differences are considered a way of minimizing niche overlap.  Sexual selection or co-evolution (related to predation) may also contribute to the variation observed.  Third, trends detected in the fossil record include three major phases of diversification, in the Eocene, Oligocene and late Miocene.


Chapter 34. Humans among Primates
(Groves, C.P.)

          The diversity of primates, barriers to dispersal and taxonomic controversy are briefly introduced before the origins and relationships of primate groups are discussed.  The relative age of primates (Cretaceous remains) is considered together with the controversy about possible closely related or ancestral groups.  Findings using different techniques are compared.
          Early radiations of primates are then considered on the basis of a number of sub-orders, starting with older plesiomorphic forms and progressing to more recent anthropoids.  Then the later evolution (from early Miocene) of primate assemblages is discussed in more detail, leading to a summary of hominoid history.  The family Hominidae is considered in detail with comparisons of dentition and skulls and then the major changes (bipedal gait, neoteny) resulting in the development of Homo sapiens are discussed.
          Fossil hominines (including the australopithecines and Homo) are compared and their movements or ranges briefly discussed.  DNA data are used to postulate relationships within the Homo assemblage.
          Finally, the focus moves to the timing and method of arrival of humans in Australasia, as well as the relationships of Australian aborigines to other regional populations.  The continuing controversy relating variation between aboriginal populations and separate waves of immigration is briefly outlined.


Chapter 35. Combined Keys to Extant Australasian Mammals
(McKay, G.M.)

          After a brief explanation of the required features for good keys and major sources for subsequent material the author provides two series of keys – the first based on external features, the second on skull characteristics.  These keys provide for identification of order and family of all Australasian mammals.  Where possible the external features keys extend identification to the generic level, but for some families this is not possible – in these instances genera are tabulated with brief descriptions of important characters.
          Notes are included on numbers of species recognized within taxa and the geographic distribution of each group or subgroup.  Finally the major published resources to taxonomy and ranges of mammals in the region are discussed, emphasizing the relatively poor knowledge of New Guinea.


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ACCELERATED CHANGE – THE REGIONAL FUTURE

Chapter 36. Molecular Systematics: Implications for Phylogeny, Biogeography and Conservation
(Colgan, D.J. and O’Meally, D.)

          The application of genetic information to studies of the taxonomic status of species or populations, vertebrate phylogenetics, biogeography and field conservation biology is reviewed.  The principles of available techniques are outlined and comments included about the ease and efficiency of each as well as their current or prospective importance.  Techniques discussed are: (i) allozyme electrophoresis, (ii) isoelectric focusing and 2-D electrophoresis, (iii) protein sequencing, (iv) immunology and serology, (v) cytogenetics, (vi) DNA-DNA hybridization, (vii) restriction fragment length polymorphisms, (viii) minisatellites, (ix) the polymerase chain reaction and variants such as random amplified polymorphic DNA’s, amplified restriction fragment length polymorphisms or microsatellites, (x) DNA and RNA sequencing, (xi) various types of mutation detection including the chemical cleavage of modified DNA, PCR-RFLP, single-strand conformational polymorphism and the ligase chain reaction, and (xii) short interspersed elements. 
          The choice of sequences for investigation is discussed in terms of codon position, cellular location (e.g. mitochondrial DNA), intron/exon genomic structure and possible associations with pseudogenes.  Applications of these techniques to the molecular zoology of Australian vertebrate faunas are demonstrated by case studies of particular groups.  The use of molecular techniques in phylogenetics is illustrated by the basal evolution of the marsupials, in biogeography by the distribution of fruit bats and in conservation biology by the use of genetic criteria for the selection of natural reserves.


Chapter 37. The Role of GIS in Systematic Conservation Planning
(Flemons, P. and Cassis, G.)

          The importance of Geographic Information Systems to the development of concepts underlying systematic conservation planning is emphasized and the application of GIS within the conservation planning process is examined.  Firstly, the problem of survey site selection, in order to maximize representativeness of data, is considered briefly in terms of multi-dimensional mapping and a p-median index.  Aspects of the use of taxonomic and spatial surrogates, to measure biodiversity, discussed include: the use of WORLDMAP, several species modelling techniques, mapped land classes and environmental classifications or ordinations.
The problems in previous processes of reserve selection and design are briefly outlined.  Then recent research on selection, based on tenets of representativeness, complementary and irreplaceability, using computer algorithms to select minimal areas that include all features for conservation is described.  The additional criterion of species turnover is discussed, emphasizing differences between vertebrates and invertebrates and explaining limitations of the minimal set strategy over time.  Reserve design is considered in terms of size, configuration, connectivity and heterogeneity.  The development of integrated GIS-based decision support systems for reserve selection and design is briefly outlined together with the main categories of data.
Finally, several conservation planning frameworks are compared.  The importance of global ‘hotspots’ is considered together with the development of the Systematic Conservation Planning for local Regional Forestry Agreements.  The research emphasis of the US GAP Analysis Program is contrasted with the management planning and land acquisition aspects of the privately-funded Nature Conservancy.


Chapter 38. Determining Marine Movements of Australasian Pinnipeds
(Bradshaw, C.J.A., Hindell, M.A., Littnan, C. and Harcourt, R.G.)

          First the diversity of pinnipeds in the region is summarized, then a brief outline of the exploitation and recent history relating to these animals is provided.  The types of questions that need to be addressed for effective management are listed and the utilization of new technologies is introduced.
          The techniques discussed include satellite telemetry, geo-location, acoustic tracking and radio tracking – the particular advantages of each technology are explained.  Major results from studies (using these technologies) of the Australian fur seal, southern elephant seal and Weddell seal are described.  The studies selected focus on a poorly known and clandestine phase of life history – foraging at sea and associated behaviour patterns.  Overall objectives include: assessing the degree of overlap or competition with commercial fisheries; utilization of particular areas of the Southern Ocean by pinniped populations; and incorporation of telemetric data in decisions about marine reserves.
          Future development of Archival Tag technology is also briefly discussed, in terms of the capacity for remote measurement of key oceanic parameters (e.g. temperatures, temperature gradients), to high levels of precision.


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