Here I show how fitness landscapes can be used to understand the relative importance of developmental and ecological change in initiating morphological innovation. Key is the use of morphogenetic ‘rules’ as the axes of the landscape, which enables explicit incorporation of the contribution that specific morphologies make to fitness. Four modes of fitness landscape evolution are identified: (1) change in the density of peaks on the landscape, driven by an increase in the number of selective pressures encountered; (2) change in the dimensionality of the landscape through the addition of morphogenetic rules; (3) change in the size of one or more dimensions of the landscape through elaboration of already existing morphogenetic rules; and, (4) shifting the position of peaks in the landscape. Morphological innovation is initiated by ecological change in Mode (1), for example the Cambrian explosion of animals, and Mode (4), for example, when taxa such as sticklebacks make a shift in environment, or during coevolutionary escalation. Morphological change is initiated by developmental innovation for Mode (2), typified by some macroevolutionary innovations, such as the emergence of jaws, and in Mode (3), for example, in the differentiation of flower morphology facilitated by gene duplication of the B-class developmental genes.

The evolution of the Dipnoi is displayed in the Early Devonian in south-eastern Australia. The main points at issue are as follows. (a) The development of the tubercles in the two-layered rostral region of the skull. (b) The nerves ophthalmicus profundus V and opthalmicus superficialis VII, and their sensory function. (c) The abundance of fine tubules between these tubules and the dermal plates of the skull roof extending posterior to the pineal region. (d) The massive pterygoids and the restriction of the parasphenoids to a small posterior position. (e) The position of the bucco-hypophysial canal running to a buccal opening near the posterior of the pterygoids. (f) The presence of a rostral region, misnamed the ‘dentary’, in the mandible, with abundant tubercles serving sensory systems. (g) The presence of an anterior furrow in the mandible. Dipnoans form a separate evolutionary lineage that began in the Early Devonian. Diabolepis and associated genera are not Dipnomorphs, but are isolated genera formed by gene regulation in the early Devonian.

The ‘buchanosteid’ placoderms are best known from the Early Devonian of Australia, but also occur in China, Russia, Central Asia and the Middle East. Here we rediagnose the type species Buchanosteus confertituberculatus (Hills 1936) from the type locality at Buchan, Victoria, in the light of new material of both head and trunk shields. The superfamily Buchanosteoidea Denison, 1978 is redefined to unite taxa that share a similar skull roof with separate rostro-pineal (ethmoid) bone, and postethmoid skull pattern characterised by a large trapezoidal nuchal, strap-like short and broad preorbitals, large subrectangular centrals, small postorbitals not contacting the paranuchals, and large, elongate marginal plates. The Family Buchanosteidae is redefined on skull roof and parasphenoid shape and trunk armour features as a monotypic family within the Buchanosteoidea. A new family (Parabuchanosteidae nov.) includes taxa with the posterior lateral plate overlapping the anterior dorsolateral plate externally. Two new buchanosteids are described, Richardosteus barwickorum gen. et sp. nov., from Burrinjuck, south-eastern Australia, and Urvaspis lithuanica gen. et sp. nov., from Severnaya Zemlya, Russia.

A small collection of arthrodire remains is described from the Devonian Aztec Siltstone of southern Victoria Land, Antarctica. Barwickosteus antarcticus, gen. et sp. nov., is a small phlyctaeniid arthrodire probably closely related to Barrydalaspis from the Bokkeveld Group of South Africa. Grifftaylor antarcticus, gen. et sp. nov., is a generalised phlyctaeniid resembling Phlyctaenius and Neophlyctaenius. New specimens of Boomeraspis show that it had a high-spired trunk-armour with a median dorsal plate of similar proportions to Tiaraspis, Mithakaspis, Turrisaspis or Africanaspis. Other fragmentary median dorsal plates are provisionally referred to Turrisaspis and Mulgaspis. With these new taxa the vertebrate assemblage from the Aztec Siltstone comprises at least 37 genera and 50 species, making it one of the most diverse of Middle–Late Devonian age.

Few of the localities currently inhabited by the Australian lungfish, Neoceratodus forsteri, are in pristine condition. Most populations of wild lungfish in south-east Queensland are now isolated in reservoirs. The barriers formed by the building of dams and weirs across natural rivers separate lungfish groups from each other, cut across possible pathways for normal movement in the environment, and have additional and more serious effects. Water levels in reservoirs fluctuate in spring when lungfish are spawning, and do not allow dense stands of submerged aquatic plants to become established. Lungfish need these plants as sites for oviposition, and newly hatched young need them as refuges and sources of food. Potential recruitment of young lungfish in reservoir populations faces another threat, that of anomalous development of the embryos, hatchlings and juveniles, severe enough to kill many embryos within days of oviposition, and destroy the young fish before they are more than a few months old. Similar anomalies are not present in young fish from a river environment raised under identical conditions. Reasons for poor development, which has now been found in two reservoirs, may be related to the diet of the adult lungfish, and possibly to genetic factors.

Photographic and videographic investigations of the aerodynamic performance of four captive adult Acrobates pygmeus are described. During short (1–4 m) glides, steep angles of descent (>45°) and large angles of attack (up to 50°) were used mid-flight, and the possums failed to achieve steady velocities. During longer (>10 m) glides steady velocities of 5.3–7.5 m s^–1 were achieved, and glide angles of 21–42° and angles of attack between 36° and 45° were used. The best (lowest) glide angles used at steady velocity were similar to those documented in sugar gliders, but involved lower air speeds. During steady gliding the forelimbs of Acrobates assumed an ‘elbows-out’ disposition similar to that of Petauroides volans, and unlike that of petaurid gliders. A glide polar for Acrobates shows that it uses lower air speeds and higher sinking speeds than other gliding animals for which polars are available (several birds and one bat). Few data on the radius of turn and sinking speed were obtained; nevertheless, in accord with theory, sinking speeds were higher during tighter turns. During flight the feather-like tail was used to generate pitching movements and adjust the angle of attack and hence glide angle. However, the control of turns seems to be achieved primarily through limb adjustments.

There is increasing concern about the global decline of amphibians and reptiles. One problem with documenting declines and identifying underlying causes is the absence of historical data to compare to current data. Here we provide historic data for Kioloa on the south-eastern coast of New South Wales. In this region considerable clearing of natural forest and woodland and creation of farmland ponds took place during the second half of the 20th century. The Australian National University has a field station at Kioloa and R. E. Barwick introduced us to the field station and what was known of the herpetofauna in the mid-1980s. We undertook detailed observational surveys of the herpetofauna at this time and we revisited the area at other times, focusing on the coastal habitats. We found 13 species of frogs and 11 species of reptiles. Three further frog species and one reptile species known to occur in the area in the 1980s were not detected by us. More recently, one further frog species and six reptile species were added to the list, raising the total to 17 frog and 18 reptile species. The number and composition was similar to other locations of coastal New South Wales, except for some of the rarely encountered species. No strictly forest-dependent species were observed in the partially cleared survey area and such species presumably had already disappeared from these areas already before we commenced our observations. The frog Pseudophryne bibronii was still common in tall open-forest but was uncommon in partially cleared areas. Six species of frogs and one species of reptile presumably benefited from the anthropogenic habitat modifications. No declines of common species of reptiles occurred between the mid-1980s and 1993 but all species of frogs were very rare in 1993 due to very dry conditions. Litoria aurea, a threatened species of frog that was widespread in the mid-1980s, survives (2012) only at one site in the area.