The historical biogeography of Apsilochorema (Trichoptera,Hydrobiosidae) revised,following molecular studies

The genus Apsilochorema Ulmer, 1907 is unique in the family Hydrobiosidae Ulmer, being widely distributed in the Palaearctic, Oriental and Australian Regions. All other 49 genera in the family, except the New World Atopsyche Banks, 1905, are confined to a single biogeographical Region. This unique distribution has independently stimulated researchers to formulate competing hypotheses about the biogeographical history of the genus. Molecular sequence data from mitochondrial cytochrome oxidase I (COI) and nuclear cadherin (CAD) genes of Apsilochorema species from the Oriental and Australian areas were analysed phylogenetically. The results retain a monophyletic Apsilochorema, which forms the sistergroup to the other genera in the subfamily Apsilochorematinae. The results from the biogeographical analyses dispute the earlier assumptions of an Oriental or northern Gondwana origin for the genus, revealing unambiguously an initial Australian radiation of the ancestral Apsilochorema with a subsequent dispersal into the Oriental Region. All but one of the Apsilochorema species occurring on the Pacific islands had an Oriental ancestor. The exception is the sistergroup to the New Caledonian species, which is found in both Australia and Oriental Regions. The molecular dating analysis, using a relaxed clock model, indicates that the genus Apsilochorema is about 36.4 MY old and that it dispersed from Australia into the Oriental Region about 28.3 Ma. It also gives an estimate of the approximate ages of the dispersals into New Caledonia to about 15.3 Ma; to the Solomon Islands at about 16.2 Ma; to the Fiji Islands at about 16.1 Ma; and to the Vanuatu Islands at about 5.4 Ma.     

Phylogenetic analysis reveals multiple introductions of Cynodon species in Australia

The distinction between native and introduced flora within isolated land masses presents unique challenges. The geological and colonisation history of Australia, the world's largest island, makes it a valuable system for studying species endemism, introduction, and phylogeny. Using this strategy we investigated Australian cosmopolitan grasses belonging to the genus Cynodon. While it is believed that seven species of Cynodon are present in Australia, no genetic analyses have investigated the origin, diversity and phylogenetic history of Cynodon within Australia. To address this gap, 147 samples (92 from across Australia and 55 representing global distribution) were sequenced for a total of 3336bp of chloroplast DNA spanning six genes. Data showed the presence of at least six putatively introduced Cynodon species (C. transvaalensis, C. incompletus, C. hirsutus, C. radiatus, C. plectostachyus and C. dactylon) in Australia and suggested multiple recent introductions. C. plectostachyus, a species often confused with C. nlemfuensis, was not previously considered to be present in Australia. Most significantly, we identified two common haplotypes that formed a monophyletic clade diverging from previously identified Cynodon species. We hypothesise that these two haplotypes may represent a previously undescribed species of Cynodon. We provide further evidence that two Australian native species, Brachyachne tenella and B. convergens belong in the genus Cynodon and, therefore, argue for the taxonomic revision of the genus Cynodon.     

Molecular phylogeny and biogeography of spring-associated hydrobiid snails of the Great Artesian Basin, Australia

The Great Artesian Basin (GAB) of Australia underlies some of the driest parts of South Australia and Queensland and feeds numerous freshwater springs. Prominent and endangered components of the GAB spring community are snails of the family Hydrobiidae. This paper examines the evolutionary relationships of the entire hydrobiid fauna associated with the GAB, and includes appropriate non-GAB species to place the GAB fauna in a broader phylogenetic context. The Queensland genus Jardinella is a focus of this paper, providing a fine scale examination of relationships between spring supergroups in the northeastern regions of the GAB. Maximum parsimony and Bayesian analyses performed on 16S, CO1, and combined sequence data from 40 hydrobiid taxa found four major clades of Australian taxa. The analysis revealed that at least three separate colonization events of the GAB spring fauna have occurred. Two of these are represented by considerable radiations, (1) Jardinella to the north and east and (2) Caldicochlea, Fonscochlea, and possibly Trochidrobia in South Australia. The phylogenetic position of the latter is uncertain so it may represent yet another invasion. The third definite invasion is represented by a single species of the speciose SE Australian genus Austropyrgus in the Dalhousie Springs in South Australia. Jardinella is found to be monophyletic, and with one exception, its members in each of the Queensland spring supergroups are found to be monophyletic.     

First phylogenetic and biogeographical study of the southern bluebells (Wahlenbergia, Campanulaceae)

Wahlenbergia is a largely southern hemisphere genus of at least 260 species; within Campanulaceae only Campanula is larger. This first phylogeny of Wahlenbergia was reconstructed using about 20% of the 260 species in the genus based on the nuclear ribosomal ITS marker and the chloroplast trnL-F marker with samples from South Africa, Europe, Australia and New Zealand. Wahlenbergia was confirmed to be non-monophyletic, though most of the species form a clade. Our tree topology and date estimates indicate that Wahlenbergia diverged in South Africa about 29.6 mya, then dispersed to Australasia about 4.8 mya, thus indicating the radiation of Wahlenbergia occurred relatively recently. Radiations occurred in both of these main centres; there are currently about 170 species in South Africa and 45 species and subspecies in Australasia. New Zealand species comprise two clades, both rooted within the Australasian clade. We thus propose two dispersals from Australia to New Zealand, one leading to a radiation of species with the rhizomatous herbaceous growth form ca. 1.6 mya, and the other leading to a radiation of species with the radicate growth form 0.7 mya. Dispersals from Australia to New Zealand match the expected direction, following the west wind drift and ocean currents. The herbaceous growth form was shown to be ancestral for the genus as a whole, and polyploidy has been a mechanism of the evolution of the genus in Australasia.     

Species richness and endemism in the Western Australian flora

Aim Estimates of endemic and non‐endemic native vascular plant species in each of the three Western Australian Botanical Provinces were made by East in 1912 and Beard in 1969. The present paper contains an updated assessment of species endemism in the State. Location Western Australia comprises one third of the continental Australian land mass. It extends from 13° to 35° S and 113° to 129° W. Methods Western Australia is recognized as having three Botanical Provinces (Northern, Eremaean and South‐West) each divided into a number of Botanical Districts. Updated statistics for number of species and species endemism in each Province are based on the Census of Western Australian Plants data base at the Western Australian Herbarium ( Western Australian Herbarium, 1998 onwards). Results The number of known species in Western Australia has risen steadily over the years but reputed endemism has declined in the Northern and Eremaean Provinces where cross‐continental floras are common. Only the isolated South‐West Province retains high rates of endemism (79%). Main conclusions With 5710 native species, the South‐West Province contains about the same number as the California Floristic Province which has a similar area. The Italian mediterranean zone also contains about this number but in a smaller area, while the much smaller Cape Floristic Region has almost twice as many native species. The percentage of endemic species is highest at the Cape, somewhat less in south‐western Australia and less again in California. Italy, at 12.5%, has the lowest value. Apart from Italy, it is usual for endemism to reach high values in the largest plant families. In Western Australia, these mainly include woody sclerophyll shrubs and herbaceous perennials with special adaptations to environmental conditions. While those life forms are prominent in the Cape, that region differs in the great importance of herbaceous families and succulents, both of which are virtually absent from Western Australia. In California and Italy, most endemics are in families of annual, herbaceous perennial and soft shrub plants. It is suggested that the dominant factor shaping the South‐West Province flora is the extreme poverty of the area’s soils, a feature that emphasizes sclerophylly, favours habitat specialization and ensures relatively many local endemic species.     

The evolutionary history of Eryngium (Apiaceae, Saniculoideae): rapid radiations, long distance dispersals, and hybridizations

Eryngium is the largest and arguably the most taxonomically complex genus in the family Apiaceae. Infrageneric relationships within Eryngium were inferred using sequence data from the chloroplast DNA trnQ-trnK 5'-exon and nuclear ribosomal DNA ITS regions to test previous hypotheses of subgeneric relationships, explain distribution patterns, reconstruct ancestral morphological features, and elucidate the evolutionary processes that gave rise to this speciose genus. In total, 157 accessions representing 118 species of Eryngium, 15 species of Sanicula (including the genus Hacquetia that was recently reduced to synonymy) and the monotypic Petagnaea were analyzed using maximum parsimony and Bayesian methods. Both separate and simultaneous analyses of plastid and nuclear data sets were carried out because of the prevalence of polyploids and hybrids within the genus. Eryngium is confirmed as monophyletic and is divided into two redefined subgenera: Eryngium subgenus Eryngium and E. subgenus Monocotyloidea. The first subgenus includes all examined species from the Old World (Africa, Europe, and Asia), except Eryngium tenue, E. viviparum, E. galioides, and E. corniculatum. Eryngium subgenus Monocotyloidea includes all examined species from the New World (North, Central and South America, and Australia; herein called the "New World sensu stricto" clade) plus the aforementioned Old World species that fall at the base of this clade. Most sectional and subgeneric divisions previously erected on the basis of morphology are not monophyletic. Within the "New World sensu stricto" group, six clades are well supported in analyses of plastid and combined plastid and nuclear data sets; the relationships among these clades, however, are unresolved. These clades are designated as "Mexican", "Eastern USA", "South American", "North American monocotyledonous", "South American monocotyledonous", and "Pacific". Members of each clade share similar geographical distributions and/or morphological or ecological traits. Evidence from branch lengths and low sequence divergence estimates suggests a rapid radiation at the base of each of these lineages. Conflict between chloroplast and nuclear data sets is weak, but the disagreements found are suggestive that hybrid speciation in Eryngium might have been a cause, but also a consequence, of the different rapid radiations observed. Dispersal-vicariance analysis indicates that Eryngium and its two subgenera originated from western Mediterranean ancestors and that the present-day distribution of the genus is explained by several dispersal events, including one trans-Atlantic dispersal. In general, these dispersals coincide with the polytomies observed, suggesting that they played key roles in the diversification of the genus. The evolution of Eryngium combines a history of long distance dispersals, rapid radiations, and hybridization, culminating in the taxonomic complexity observed today in the genus.     

A smaller Macadamia from a more vagile tribe: inference of phylogenetic relationships, divergence times, and diaspore evolution in Macadamia and relatives (tribe Macadamieae; Proteaceae)

Tribe Macadamieae (91 spp., 16 genera; Proteaceae) is widespread across the southern hemisphere on all major fragments of Gondwana except New Zealand and India. Macadamia is cultivated outside its natural range as a "nut" crop (notably in Hawaii, where it is the principal orchard crop). We sampled seven DNA regions and 53 morphological characters from the tribe to infer its phylogeny and address the common assumption that the distribution of the extant diversity of the tribe arose by the rafting of ancestors on Gondwanan fragments. Macadamia proves to be paraphyletic with respect to the African genus Brabejum, the South American genus Panopsis, and the Australian species Orites megacarpus. We erect two new generic names, Nothorites and Lasjia, to produce monophyly at that rank. The earliest disjunctions in the tribe are inferred to be the result of long-distance dispersal out of Australia (with one possible exception), rather than vicariance. Evolution of tardy fruit dehiscence is correlated with these dispersals, and the onset of the Antarctic Circumpolar Current (ACC) precedes them. We suggest that the ancestors of extant diversity arrived on their respective continents via the ACC, and we recognize that this is a mechanism precluded, rather than facilitated, by Gondwana's terrestrial continuity.     

Rapid diversification in Australia and two dispersals out of Australia in the globally distributed bee genus,Hylaeus (Colletidae: Hylaeinae)

Hylaeus is the only globally distributed colletid bee genus, with subgeneric and species-level diversity highest in Australia. We used one mitochondrial and two nuclear genes to reconstruct a phylogeny using Bayesian analyses of this genus based on species from Australia, Asia, Africa, Europe, Hawai’i, the New World and New Zealand. Our results concord with a ca. 30 Mya Hylaeus crown age inferred by earlier studies, and we show that Hylaeus originated in Australia. Our phylogeny indicates only two dispersal events out of Australia, both shortly after the initial diversification of extant taxa. One of these dispersals was into New Zealand with only a minor subsequent radiation, but the second dispersal out of Australia resulted in a world-wide distribution. This second dispersal and radiation event, combined with very extensive early radiation of Hyleaus in Australia, poses a conundrum: what kinds of biogeographical and ecological factors could simultaneously drive global dispersal, yet strongly constrain further successful migrations out of Australia when geographical barriers appear to be weak? We argue that for hylaeine bees movement into new niches and enemy-free spaces may have favoured initial dispersal events, but that subsequent dispersals would not have entailed the original benefits of new niche space.     

TAXONOMY OF THE LENORMANDIA - LENORMANDIOPSIS COMPLEX (RHODOMELACEAE, RHODOPHYTA)

The genus Lenormandia is composed of nine species from Australia and New Zealand. Some of the these are well known, but others are rare, obscure and ill-defined. We have examined material of all described species and found that they fall into two discrete groups that differ in apex morphology and position of reproductive structures. Plants of the first group, containing the type species L. spectabilis , have a cleft apex and reproductive structures produced directly on the blade surface, whereas those of the second group have a strongly inrolled apex and produce reproductive structures dorsally on small branchlets which arise either from the margins or the midrib. The groups were also found to form discrete clades on analysis of 18S rRNA sequences. All the members of the first group are endemic to Australia, whereas the second group, designated by the new genus name Adamsiella , contains two previously described New Zealand species and a single Australian representative. In addition, two new species are described in this group from New Zealand. Members of the closely related genus Lenormandiopsis were also examined and the type species, L. latifolia , was found to conform in apex morphology and position of reproductive structures to the genus Lenormandia. Accordingly Lenormandiopsis has been subsumed within Lenormandia. The remaining three members of the former genus Lenormandiopsis , however, were found to differ from both the type species and the genus Lenormandia and consequently have been transferred to the separate genus Geraldia , along with a new species from Geraldton, Western Australia which is designated as the type.     

Species assembly and the evolution of community structure

Summary In this paper I consider the evolutionary and ecological implications of an assembly rule which was derived empirically from studies on a heathland small-mammal community in south-eastern Australia. This rule has been tested successfully against 52 heathland small-mammal assemblages. Here it is shown to hold also for 80 forest assemblages of small mammals spanning a latitudinal range from 27°S to 43°S in south-eastern Australia. The observed forest communities are predicted by the rule and they deviate significantly from random assemblages. I suggest that the unique evolutionary history of the Australian fauna has made these patterns more apparent. The rule is simply stated as: There is a much higher probability that each species entering a community will be drawn from a different functional group (genus or other taxonomically related group of species with similar diets) until each group is represented, before the cycle repeats. A theoretical basis for the rule is proposed which extends the niche compression hypothesis to cover evolutionary time. Evolutionary constraints on adaptations for diet selection are greater than those operating on habitat selection. Successful tests in North America for the granivorous desert rodent guild and the mixed-forest insectivore guild support a wider application of this rule than the Australian communities from which it was derived. A speculative model is proposed in which the mechanisms involved in the operation of this rule shape the evolution of community structure.     

‘Back to Africa’: increased taxon sampling confirms a problematic Australia‐to‐Africa bee dispersal event in the Eocene

Colletidae is a predominantly southern hemisphere bee family with a Late Cretaceous origin and with an inferred ancestral region covering late Gondwanan South America, Antarctica and Australia. One highly diverse colletid subfamily, Euryglossinae, is entirely restricted to Australia and the strictly Afrotropical subfamily Scrapterinae has been inferred as its sister clade. This has led to suggestions that Scrapterinae represents a highly unusual post‐Gondwanan dispersal from Australia to Africa, but phylogenetic studies to date have included only minimal representatives from each subfamily. Here we greatly increase the level of species sampling of both subfamilies and develop a molecular phylogeny based on one mitochondrial and two nuclear genes. Our results indicate that the broad results of earlier studies are robust to substantially greater taxon sampling, and we infer a divergence date between the two subfamilies in the early Eocene. Dispersal pathways between Africa and Australia during that time are problematic, with several studies suggesting dispersals via the now largely submerged Kerguelen and Crozet Plateaus. Our results contribute another example of a puzzling sister‐clade relationship between African and Australian taxa and indicate the need to better understand southern hemisphere subaerial configurations, including Antarctica, and ocean and wind currents at those times.     

Anzygina, a new genus for some Australasian microleafhopper species formerly placed in the genus Zygina Fieber (Cicadellidae: Typhlocybinae: Erythroneurini)

Species of Erythroneurini (Cicadellidae: Typhlocybinae) currently placed in the genus Zygina and found in Australia, New Zealand and some neighbouring islands are transferred to the new genus Anzygina , type species Erythroneura sidnica Kirkaldy, following comparison with the type species of the genus: Typhlocyba nivea Mulsant and Rey. New combinations are Anzygina sidnica (Kirkaldy), Anzygina honiloa (Kirkaldy), Anzygina melanogaster (Kirkaldy) and Anzygina sativae (Evans) from Australia, Anzygina toetoe (Cumber), Anzygina agni (Knight), Anzygina dumbletoni (Ghauri) and Anzygina ramsayi (Knight) from New Zealand, Anzygina zealandica (Myers) from Australia and New Zealand, Anzygina jowettae (Knight) from Norfolk Island and Anzygina medioborealis (Ghauri) from Papua New Guinea. Lectotypes are designated for Erythroneura honiloa Kirkaldy and E. sidnica Kirkaldy. Anzygina billi sp.n. is described from SE Qld, and Anzygina barrattae sp.n. is described from the South Island of New Zealand. A. agni is a new record for Australia and is presumed to be Australian in origin. A. dumbletoni has a distribution which suggests that it also is introduced to New Zealand although its origins are not known. A. ramsayi, A. barrattae and A. toetoe , all of which appear to be New Zealand endemics, show affinity with each other based on aedeagal structure. A key to these species, based on males, is provided. The lack of male syntypes for Erythroneura honiala Kirkaldy and Erythroneura lubra Kirkaldy precludes establishment of their identities relative to other species of the genus, and both names are regarded as having nomen dubium status. Australian species not transferred to Anzygina are Zygina evansi (Ross) and Zygina ipoloa (Kirkaldy), both of which belong elsewhere.     

Botryocladius gen.n.: a new transantarctic genus of orthocladiine midge (Diptera: Chironomidae)

A new genus of orthocladiine Chironomidae, Botryocladius (type species B. grapeth sp.n. from eastern Australia) is described and illustrated in all life history stages. All thirteen included species are described as new, six from eastern Australia (B. grapeth, B. brindabella, B. mdfrc, B. collessi, B. tasmania, B. australoalpinus), two from Western Australia (B. bibulmun and B. freemani), one from ephemeral streams in Australia (B. petrophilus) and four from Patagonian Argentina and Chile (B. edwardsi, B. glacialis, B. mapuche and B. tronador). All Australian species are known from at least pupal exuviae, most from adult males and several from larvae. In contrast, only B. edwardsi amongst Neotropical species is known from the adult male; all others are described from pupal exuviae. The immature stages are lotic in Australian permanent and temporary streams and Patagonian glacial streams and rivers, and lentic in Neotropical glacial-fed and Australian subalpine lakes. Botryocladius appears to belong with a grouping centred on two formally undescribed taxa from Australia. The genus evidently demonstrates a vicariant distribution with at least two sister-group relationships between South American and Australian taxa, providing a minimum dating for the clade of 38 Ma., with apparent absence from New Zealand indicating a maximum date of 80 Ma.     

Molecular evidence for bicontinental hybridogenous genomic constitution in Lepidium sensu stricto (Brassicaceae) species from Australia and New Zealand

Lepidium sensu stricto (s.s.) (Brassicaceae) (ca. 150 species) is distributed worldwide with endemic species on every continent. It is represented in Australia and New Zealand by 19 and seven native species, respectively. In the present study we used a nuclear ribosomal internal transcribed spacer (ITS) phylogeny in comparison with a cpDNA phylogeny to unravel the origin of Australian/New Zealand species. Although phylogenetic relationships within Lepidium s.s. were not fully resolved, the cpDNA data were in agreement with a Californian origin of Lepidium species from Australia/New Zealand. Strongly conflicting signals between the cp- and nuclear DNA phylogenetic analysis clearly indicated hybridogenous genomic constitution of Australian Lepidium s.s. species: All 18 studied Australian/New Zealand Lepidium s.s. species examined shared a Californian cpDNA type. While eleven Australian/New Zealand species appeared to harbor a Californian ITS type, a group of seven species shared a South African ITS type. This pattern is most likely explained by two trans-oceanic dispersals of Lepidium from California and Africa to Australia/New Zealand and subsequent hybridization followed by homogenization of the ribosomal DNA either to the Californian or South African ITS type in the two different lineages. Calibration of our molecular trees indicates a Pliocene/Pleistocene origin of Lepidium in Australia/New Zealand. Low levels of cpDNA and ITS sequence divergence and unresolved topologies within Australian/New Zealand species suggest a rapid and recent radiation of Lepidium after the hybridization event. This coincides with dramatic climatic changes in that geological epoch shaping the composition of the vegetation.     

New species of the myrmecophile Polyplocotes Westwood (Coleoptera: Ptinidae) from South Australia

Six new species of the Australian myrmecophilous ptinid genus Polyplocotes are described from South Australia. Three are from the deserts of central Australia, one from the Franklin Islands in the Great Australian Bight, one from Eyre Peninsula and one from the Riverland region. Morphologically, the majority of these new species are conventional Polyplocotes , but two are less typical. The characters uniting the genus are explored in the discussion, and comparisons are made to related genera. Although the six new species described here have not been observed in the field, the species of this genus are known to be myrmecophilous, and ant – beetle interactions similar to those seen in other spider beetles might occur between these new species and their host ants.     

Review of haploporid (Trematoda) genera with ornate muscularisation in the region of the oral sucker, including four new species and a new genus

Species of the Haploporidae Nicoll, 1914 with elaborate muscularisation of the oral sucker belong in three trematode genera, including three new species and a new genus from the intestine of fishes in Australian waters. Spiritestis Nagaty, 1948 is resurrected and S. herveyensis n. sp. is described from the mullet Moolgarda seheli (Forsskål) collected in Hervey Bay, Queensland, Australia; the latter differs from S. arabii Nagaty, 1948 in that the position of the genital pore is pharyngeal rather than post-pharyngeal and the geographical range is off Australia rather than the Red Sea. A new genus is proposed for two new species, with a uniquely ornamented oral sucker, which infect Australian scatophagids. Members of Capitimitta n. g. are distinguished from Waretrema Srivastava, 1937, species of which have a simple oral sucker with six radially arranged anterior muscular lobes, in that their oral sucker is V-shaped with six embedded muscular finger-like structures in the anteroventral portion. The relatively small C. darwinensis n. sp., collected from Selenotoca multifasciata (Richardson) at Darwin, Northern Territory, Australia, is distinguished from C. costata n. sp., collected from Scatophagus argus (Linnaeus) in the same locality and S. multifasciata off Brisbane, Australia, and by having smaller eggs, a vitellarium commencing at a level close to the ventral sucker rather than at greater than one ovarian length posterior to the ventral sucker, and shorter tegumental body spines. Sequence data of a c.2,500 bp region of the 3′ end of 18S, the entire ITS region and the 5′ end of the 28S revealed that Spiritestis and Capitimitta are not as closely related as some morphological features would suggest and are probably not the closest relative of each other. What has been reported as Waretrema piscicolum Srivastava, 1937 probably consists of several species, some in different genera, and one, based on material collected by Dr Masaaki Machida, is proposed as Spiritestis machidai n. sp. from Crenimugil crenilabis (Forsskål) off Japan. Phylogenetic hypotheses, based on analysis of an alignment of partial 28S sequences with other haploporids, provide a framework for the evaluation of interrelationships within the Haploporidae. These analyses show that: (1) Spiritestis and Capitimitta are supported within the Haploporidae; (2) branches to Forticulcita Overstreet, 1982, Saccocoelioides Szidat, 1954, Spiritestis and Capitimitta create a clade that is sister to haploporines from the Mediterranean Sea; (3) the branch to Saccocoelioides, Spiritestis and Capitimitta create a polytomy; and (4) the two new species of Capitimitta, plus an immature specimen of an unnamed species, form a monophyletic clade.     

Nuclear Ribosomal ITS Functional Paralogs Resolve the Phylogenetic Relationships of a Late-Miocene Radiation Cycad Cycas (Cycadaceae)

Cycas is the most widespread and diverse genus among the ancient cycads, but the extant species could be the product of late Miocene rapid radiations. Taxonomic treatments to date for this genus are quite controversial, which makes it difficult to elucidate its evolutionary history. We cloned 161 genomic ITS sequences from 31 species representing all sections of Cycas. The divergent ITS paralogs were examined within each species and identified as putative pseudogenes, recombinants and functional paralogs. Functional paralogs were used to reconstruct phylogenetic relationships with pseudogene sequences as molecular outgroups, since an unambiguous ITS sequence alignment with their closest relatives, the Zamiaceae, is unachievable. A fully resolved and highly supported tree topology was obtained at the section level, with two major clades including six minor clades. The results fully supported the classification scheme proposed by Hill (2004) at the section level, with the minor clades representing his six sections. The two major clades could be recognised as two subgenera. The obtained pattern of phylogenetic relationships, combined with the different seed dispersal capabilities and paleogeography, allowed us to propose a late Miocene rapid radiation of Cycas that might have been promoted by vicariant events associated with the complex topography and orogeny of South China and adjacent regions. In contrast, transoceanic dispersals might have played an important role in the rapid diversification of sect. Cycas, whose members have evolved a spongy layer in their seeds aiding water dispersals.     

Phylogenetic relationships of the globally distributed freshwater prawn genus Macrobrachium (Crustacea: Decapoda: Palaemonidae): biogeography, taxonomy and the convergent evolution of abbreviated larval development

There has hitherto been little research into evolutionary and taxonomic relationships amongst species of the freshwater prawn genus Macrobrachium Bate across its global distribution. Previous work by the authors demonstrated that the endemic Australian species did not evolve from a single ancestral lineage. To examine whether other regional Macrobrachium faunas also reflect this pattern of multiple origins, the phylogeny of 30 Macrobrachium species from Asia, Central/South America and Australia was inferred from mitochondrial 16S rRNA sequences. Phylogenetic relationships demonstrate that, despite some evidence for regional diversification, Australia, Asia and South America clearly contain Macrobrachium species that do not share a common ancestry, suggesting that large-scale dispersal has been a major feature of the evolutionary history of the genus. The evolution of abbreviated larval development (ALD), associated with the transition from an estuarine into a purely freshwater lifecycle, was also mapped onto the phylogeny and was shown to be a relatively homoplasious trait and not taxonomically informative. Other taxonomic issues, as well as the evolutionary origins of Macrobrachium , are also discussed.