Endemic Radiation Research Articles

Biogeographic discordance of molecular phylogenetic and phenotypic variation in a continental archipelago radiation of land snails

BackgroundIn island archipelagos, where islands have experienced repeated periods of fragmentation and connection through cyclic changes in sea level, complex among-island distributions might reflect historical distributional changes or local evolution. We test the relative importance of these mechanisms in an endemic radiation of Rhagada land snails in the Dampier Archipelago, a continental archipelago off the coast of Western Australia, where ten morphospecies have complex, overlapping distributions.ResultsWe obtained partial mtDNA sequence (COI) for 1015 snails collected from 213 locations across 30 Islands, and used Bayesian phylogenetic analysis and Analysis of Molecular Variance (AMOVA) to determine whether geography or the morphological taxonomy best explains the pattern of molecular evolution. Rather than forming distinct monophyletic groups, as would be expected if they had single, independent origins, all of the widely distributed morphospecies were polyphyletic, distributed among several well-supported clades, each of which included several morphospecies. Each mitochondrial clade had a clear, cohesive geographic distribution, together forming a series of parapatric replacements separated by narrow contact zones. AMOVA revealed further incongruence between mtDNA diversity and morphological variation within clades, as the taxonomic hypothesis always explained a low or non-significant proportion of the molecular variation. In contrast, the pattern of mtDNA evolution closely reflected contemporary and historical marine barriers.ConclusionsDespite opportunities for distributional changes during periods when the islands were connected, there is no evidence that dispersal has contributed to the geographic variation of shell form at the broad scale. Based on an estimate of dispersal made previously for Rhagada, we conclude that the periods of connection have been too short in duration to allow for extensive overland dispersal or deep mitochondrial introgression. The result is a sharp and resilient phylogeographic pattern. The distribution of morphotypes among clades and distant islands is explained most simply by their parallel evolution.

A molecular phylogeny of Pacific honeyeaters (Aves: Meliphagidae) reveals extensive paraphyly and an isolated Polynesian radiation

We investigated the molecular phylogenetic placement of 14 species of Pacific island honeyeaters (Aves: Meliphagidae) in the broader context of an existing family-level phylogeny. We examined the evolutionary history of Pacific honeyeater lineages to assess the accuracy of current taxonomies and to evaluate their biogeographic history. We compare these biogeographic patterns to other Pacific birds to identify emergent patterns across lineages. We found strong support for a previously unknown endemic radiation in central Polynesia, which comprises five genera: Meliarchus, Guadalcanaria, Gymnomyza, Xanthotis, and Foulehaio. Conversely, other Pacific lineages were found to be strongly allied with continental radiations (e.g., Philemon eichhorni, P. cockerelli, and Lichmera incana). Our results necessitated taxonomic changes, both at the generic level (e.g., Xanthotis, Melidectes/Vosea, and Glycifohia/Gliciphila) and regarding species limits within polytypic species. Here, we discuss species limits in Foulehaio and Gymnomyza and recommend elevating three nominal subspecies of Foulehaio to species status, each of which forms well-differentiated clades.

<p><strong>Systematic review of diplommatinid land snails (Caenogastropoda, Diplommatinidae) endemic to the Palau Islands. (1) Generic classification and revision of <em>Hungerfordia</em> </strong><br /><strong>species with highly developed axial ribs</strong></p>

Diplommatinidae is a family of terrestrial caenogastropod snails that shows extensive species diversity and endemic radiation within the Palau (Belau) Islands. In this paper, we revised the taxonomy of Palauan endemic diplommatinids based on the comparative morphology of shell, operculum, radula, and genitalia. Although the generic classification of Palauan diplommatinids has been confusing, they are currently classified into two genera, Hungerfordia Beddome, 1889 and Palaina Semper, 1865. Palauan diplommatinids of these two genera are primarily distinguished by the radular, genital and operculum morphology. However, shell morphology, on which taxonomy has traditionally been based, does not provide definitive characters for generic identification, because shell shape and sculpture are highly variable within each genus. Although Hungerfordia has long been known as a monotypic genus, the current study redefines the endemic genus to include a wider range of species that were formerly placed in Diplommatina or Palaina. Following species are transferred to Hungerfordia: H. alata (Crosse, 1866) comb. nov.; H. lamellata (Crosse, 1866) comb. nov.; H. pyramis (Crosse, 1866) comb. nov.; H. ringens (Crosse, 1866) comb. nov.; H. polymorpha (Crosse, 1866) comb. nov.; H. inflatula (Crosse, 1866) comb. nov.; H. lutea (Beddome, 1889) comb. nov.; H. aurea (Beddome, 1889) comb. nov.; H. gibboni (Beddome, 1889) comb. nov.; H. crassilabris (Beddome, 1889) comb. nov. Pseudopalaina Moellendorff in Kobelt & Moellendorff, 1898 (synonym nov.) is demoted as a junior synonym of Hungerfordia. Palaina is also redefined based on the internal shell features and operculum morphology, in addition to the external shell characters. Furthermore, Eupalaina Kobelt & Moellendorff, 1898 is restored as a subgenus of Palaina for Palauan species on the basis of a genital character. The taxonomy of Hungerfordia species with highly developed axial ribs is revised. H. pelewensis Beddome, 1889, H. lamellata (Crosse, 1866) comb. nov., and H. alata (Crosse, 1866) comb. nov. are redescribed with new morphological data. Following new taxa are described: H. triplochilus sp. nov., H. expansilabris sp. nov., H. nudicollum sp. nov., H. echinata echinata sp. et subsp. nov., H. echinata tubulispina subsp. nov., H. elegantissima sp. nov., H. goniobasis goniobasis sp. et subsp. nov., H. goniobasis dmasechensis subsp. nov., H. subalata sp. nov., H. pteropurpuroides sp. nov., H. papilio papilio sp. et subsp. nov., H. papilio stenoptera subsp. nov..

Systematic review of diplommatinid land snails (Caenogastropoda, Diplommatinidae) endemic to the Palau Islands. (1) Generic classification and revision of Hungerfordia species with highly developed axial ribs.

Diplommatinidae is a family of terrestrial caenogastropod snails that shows extensive species diversity and endemic radiation within the Palau (Belau) Islands. In this paper, we revised the taxonomy of Palauan endemic diplommatinids based on the comparative morphology of shell, operculum, radula, and genitalia. Although the generic classification of Palauan diplommatinids has been confusing, they are currently classified into two genera, Hungerfordia Beddome, 1889 and Palaina Semper, 1865. Palauan diplommatinids of these two genera are primarily distinguished by the radular, genital and operculum morphology. However, shell morphology, on which taxonomy has traditionally been based, does not provide definitive characters for generic identification, because shell shape and sculpture are highly variable within each genus. Although Hungerfordia has long been known as a monotypic genus, the current study redefines the endemic genus to include a wider range of species that were formerly placed in Diplommatina or Palaina. Following species are transferred to Hungerfordia: H. alata (Crosse, 1866) comb. nov.; H. lamellata (Crosse, 1866) comb. nov.; H. pyramis (Crosse, 1866) comb. nov.; H. ringens (Crosse, 1866) comb. nov.; H. polymorpha (Crosse, 1866) comb. nov.; H. inflatula (Crosse, 1866) comb. nov.; H. lutea (Beddome, 1889) comb. nov.; H. aurea (Beddome, 1889) comb. nov.; H. gibboni (Beddome, 1889) comb. nov.; H. crassilabris (Beddome, 1889) comb. nov. Pseudopalaina Moellendorff in Kobelt & Moellendorff, 1898 (synonym nov.) is demoted as a junior synonym of Hungerfordia. Palaina is also redefined based on the internal shell features and operculum morphology, in addition to the external shell characters. Furthermore, Eupalaina Kobelt & Moellendorff, 1898 is restored as a subgenus of Palaina for Palauan species on the basis of a genital character. The taxonomy of Hungerfordia species with highly developed axial ribs is revised. H. pelewensis Beddome, 1889, H. lamellata (Crosse, 1866) comb. nov., and H. alata (Crosse, 1866) comb. nov. are redescribed with new morphological data. Following new taxa are described: H. triplochilus sp. nov., H. expansilabris sp. nov., H. nudicollum sp. nov., H. echinata echinata sp. et subsp. nov., H. echinata tubulispina subsp. nov., H. elegantissima sp. nov., H. goniobasis goniobasis sp. et subsp. nov., H. goniobasis dmasechensis subsp. nov., H. subalata sp. nov., H. pteropurpuroides sp. nov., H. papilio papilio sp. et subsp. nov., H. papilio stenoptera subsp. nov..

Molecular phylogeny and biogeography of the Hawaiian craneflies Dicranomyia (Diptera: Limoniidae).

The Hawaiian Diptera offer an opportunity to compare patterns of diversification across large and small endemic radiations with varying species richness and levels of single island endemism. The craneflies (Limoniidae: Dicranomyia) represent a small radiation of 13 described species that have diversified within the Hawaiian Islands. We used Bayesian and maximum likelihood approaches to generate a molecular phylogeny of the Hawaiian Dicranomyia using a combination of nuclear and mitochondrial loci, estimated divergence times and reconstructed ancestral ranges. Divergence time estimation and ancestral range reconstruction suggest that the colonization that led to most of the diversity within the craneflies arrived prior to the formation of Kauai and demonstrates that the two major clades within that radiation contrast sharply in their patterns of diversification.

Convergent evolution of morphology and habitat use in the explosive Hawaiian fancy case caterpillar radiation

Species occurring in unconnected, but similar habitats and under similar selection pressures often display strikingly comparable morphology, behaviour and life history. On island archipelagos where colonizations and extinctions are common, it is often difficult to separate whether similar traits are a result of in situ diversification or independent colonization without a phylogeny. Here, we use one of Hawaii's most ecologically diverse and explosive endemic species radiations, the Hawaiian fancy case caterpillar genus Hyposmocoma, to test whether in situ diversification resulted in convergence. Specifically, we examine whether similar species utilizing similar microhabitats independently developed largely congruent larval case phenotypes in lineages that are in comparable, but isolated environments. Larvae of these moths are found on all Hawaiian Islands and are characterized by an extraordinary array of ecomorphs and larval case morphology. We focus on the 'purse cases', a group that is largely specialized for living within rotting wood. Purse cases were considered a monophyletic group, because morphological, behavioural and ecological traits appeared to be shared among all members. We constructed a phylogeny based on nuclear and mitochondrial DNA sequences from 38 Hyposmocoma species, including all 14 purse case species and 24 of non-purse case congeners. Divergence time estimation suggests that purse case lineages evolved independently within dead wood and developed nearly identical case morphology twice: once on the distant Northwest Hawaiian Islands between 15.5 and 9Ma and once on the younger main Hawaiian Islands around 3.0Ma. Multiple ecomorphs are usually found on each island, and the ancestral ecomorph of Hyposmocoma appears to have lived on tree bark. Unlike most endemic Hawaiian radiations that follow a clear stepwise progression of colonization, purse case Hyposmocoma do not follow a pattern of colonization from older to younger island. We postulate that the diversity of microhabitats and selection from parasitism/predation from endemic predators may have shaped case architecture in this extraordinary endemic radiation of Hawaiian insects.

Genus-level phylogeny of snakes reveals the origins of species richness in Sri Lanka

Snake diversity in the island of Sri Lanka is extremely high, hosting at least 89 inland (i.e., non-marine) snake species, of which at least 49 are endemic. This includes the endemic genera Aspidura, Balanophis, Cercaspis, Haplocercus, and Pseudotyphlops, which are of uncertain phylogenetic affinity. We present phylogenetic evidence from nuclear and mitochondrial loci showing the relationships of 40 snake species from Sri Lanka (22 endemics) to the remaining global snake fauna. To determine the phylogenetic placement of these species, we create a molecular dataset containing 10 genes for all global snake genera, while also sampling all available species for genera with endemic species occurring in Sri Lanka. Our sampling comprises five mitochondrial genes (12S, 16S, cyt-b, ND2, and ND4) and five nuclear genes (BDNF, c-mos, NT3 RAG-1, and RAG-2), for a total of up to 9582bp per taxon. We find that the five endemic genera represent portions of four independent colonizations of Sri Lanka, with Cercaspis nested within Colubrinae, Balanophis in Natricinae, Pseudotyphlops in Uropeltidae, and that Aspidura+Haplocercus represents a distinct, ancient lineage within Natricinae. We synonymize two endemic genera that render other genera paraphyletic (Haplocercus with Aspidura, and Cercaspis with Lycodon), and discover that further endemic radiations may be present on the island, including a new taxon from the blindsnake family Typhlopidae, suggesting a large endemic radiation. Despite its small size relative to other islands such as New Guinea, Borneo, and Madagascar, Sri Lanka has one of the most phylogenetically diverse island snake faunas in the world, and more research is needed to characterize the island’s biodiversity, with numerous undescribed species in multiple lineages.

First record of soft-shelled turtles (Cryptodira, Trionychidae) from the Late Cretaceous of Europe

ABSTRACT Fossil soft-shelled turtles (Trionychidae) have so far been recognized in all continents except Antarctica, based largely on remains preserving their diagnostic sculptured shell bones. The origin of the group is generally assumed to be in the Early Cretaceous of Asia, whereas they first appear in North America and Europe during the Late Cretaceous and Paleocene, respectively. Here we describe the first record of an indeterminate trionychid from the late early Campanian from southern Sweden, a part of the paleobiogeographically isolated Fenno-Scandian Shield, thus extending the stratigraphic record of the group in Europe back about 15 Ma into the Late Cretaceous. Our finding provides evidence against the currently favored dispersal scenario in which trionychid turtles are interpreted to have come to Europe first during the Paleocene either directly from North America or via Asia. The described indeterminate trionychid possibly represents a relic of a pre-Cretaceous endemic radiation of North European trionychids living mainly on the Fenno-Skandian Shield or it may indicate a potential lower latitude dispersal route of trionychids from Asia to North America via Europe during the Late Cretaceous.

Endemic evolutionary radiation of Rhagada land snails (Pulmonata: Camaenidae) in a continental archipelago in northern Western Australia

In the Dampier Archipelago of Western Australia's Pilbara Region, several locally endemic, morphologically distinctive species of Rhagada land snails occur, contrasting with the morphologically conservative species with wider distributions on the adjacent mainland. To test alternative origins of this unusual local diversity in a continental archipelago, we examined sequences of the cytochrome oxidase subunit 1 and 16S mitochondrial genes in 22 described species and eight undescribed forms, including all known morphospecies from the Pilbara Region's Dampier Archipelago and adjacent mainland. Phylogenetic analyses consistently resolved four, deep clades within the Pilbara Region, with a mean sequence divergence of 15–18%. All but one of the species from the Dampier Archipelago formed one of the major clades, indicating that the morphological radiation in the archipelago evolved locally, rather than through multiple, relictual mainland lineages. Morphological divergence spanning almost that of the entire genus was within a subclade with sequence divergence < 4%, highlighting the disconnection between morphological diversification and levels of molecular genetic divergence. This in situ morphological radiation in the Dampier Archipelago, which transcends variation seen over much larger distances on the mainland, is unusual for a continental archipelago, and may relate to local heterogeneity of land forms. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 316–327.

Diversification and the adaptive radiation of the vangas of Madagascar.

The vangas of Madagascar exhibit extreme diversity in morphology and ecology. Recent studies have shown that several other Malagasy species also are part of this endemic radiation, even as the monophyly of the clade remains in question. Using DNA sequences from 13 genes and representatives of all 15 vanga genera, we find strong support for the monophyly of the Malagasy vangids and their inclusion in a family along with six aberrant genera of shrike-like corvoids distributed in Asia and Africa. Biogeographic reconstructions of these lineages include both Asia and Africa as possible dispersal routes to Madagascar. To study patterns of speciation through time, we introduce a method that can accommodate phylogenetically non-random patterns of incomplete taxon sampling in diversification studies. We demonstrate that speciation rates in vangas decreased dramatically through time following the colonization of Madagascar. Foraging strategies of these birds show remarkable congruence with phylogenetic relationships, indicating that adaptations to feeding specializations played a role in the diversification of these birds. Vangas fit the model of an 'adaptive radiation' in that they show an explosive burst of speciation soon after colonization, increased diversification into novel niches and extraordinary ecomorphological diversity.

Hidden biodiversity in rare northern Australian vertebrates: the case of the clawless geckos (Crenadactylus, Diplodactylidae) of the Kimberley

Context The phylogenetic diversity and biogeography of most animal and plant lineages endemic to the Australian Monsoonal tropics remains poorly understood. Of particular note (and in contrast to many other tropical regions in both Australia and elsewhere) is the current paucity of evidence for diverse endemic radiations of restricted-range taxa. Aims To use recently collected material from major surveys of the Kimberley Islands, Western Australia, to expand on a previous study that provided preliminary evidence of very high levels of geographically structured phylogenetic diversity in a lineage of tiny geckos (Crenadactylus). Methods Mitochondrial (ND2) and nuclear (RAG-1) sequence data were used to estimate the relationships, phylogenetic diversity and timescale of diversification of all populations of Crenadactylus from northern Australia from which samples for genetic analysis were available. Key results In striking contrast to the two subspecies currently recognised in the Kimberley, our analyses confirm the existence of a notable diversity of highly divergent and apparently allopatric lineages within the Kimberley, including at least 10 that are estimated to date to the late Pliocene/early Miocene (or earlier) and seven that we recognise as candidate new species. Most of this diversity is concentrated in the high-rainfall zone along the western edge of the Kimberley. Key conclusions A growing number of genetic datasets are revealing northern Australian vertebrate clades characterised by the juxtaposition of deeply divergent and highly geographically structured genetic diversity on the one hand, and major geographic gaps in sampling that impede full assessment of the distribution and taxonomic significance of this diversity on the other. Implications There is a pressing need for further surveys, voucher material and phylogenetic analyses to allow us to properly understand the diversity, biogeography and conservation needs of the northern Australian biota.

Diversity and distribution of avian haematozoan parasites in the western Indian Ocean region: a molecular survey

The genetic diversity of haematozoan parasites in island avifauna has only recently begun to be explored, despite the potential insight that these data can provide into the history of association between hosts and parasites and the possible threat posed to island endemics. We used mitochondrial DNA sequencing to characterize the diversity of 2 genera of vector-mediated parasites (Plasmodium and Haemoproteus) in avian blood samples from the western Indian Ocean region and explored their relationship with parasites from continental Africa. We detected infections in 68 out of 150 (45·3%) individuals and cytochrome b sequences identified 9 genetically distinct lineages of Plasmodium spp. and 7 lineages of Haemoproteus spp. We found considerable heterogeneity in parasite lineage composition across islands, although limited sampling may, in part, be responsible for perceived differences. Two lineages of Plasmodium spp. and 2 lineages of Haemoproteus spp. were shared by hosts in the Indian Ocean and also on mainland Africa, suggesting that these lineages may have arrived relatively recently. Polyphyly of island parasites indicated that these parasites were unlikely to constitute an endemic radiation and instead probably represent multiple colonization events. This study represents the first molecular survey of vector-mediated parasites in the western Indian Ocean, and has uncovered a diversity of parasites. Full understanding of parasite community composition and possible threats to endemic avian hosts will require comprehensive surveys across the avifauna of this region.

Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

AbstractThe Greater Cape Floristic Region (GCFR) of southern Africa is characterised by large, endemic radiations of flowering plants, the so‐called 'Cape Clades', but it is unknown whether such radiations are also found in non‐angiosperms. We hypothesise that GCFR‐endemic lineages exist in the xeric adapted cheilanthoid ferns. To test this hypothesis with special emphasis on the alternative hypothesis of frequent colonization, the phylogenetic relations, divergence times, and ancestral areas of the cheilanthoid ferns of the GCFR and adjacent regions are investigated. The dataset includes 22 cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR‐endemics are part of two clades that diversified in the Afro‐Madagascan region. The GCFR‐endemics are further concentrated in three high‐endemism subclades that did not originate simultaneously, but within the timeframe of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro‐Madagascan clades were likely GCFR‐endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR appears to stem primarily from in situ diversification, not from immigration. This pattern resembles the numerous radiations of angiosperm clades in the GCFR, and may be caused by the same factors. We did not find evidence for rapid, synchronised radiations as documented for some, albeit not all, angiosperm Cape Clades. High diversification within and dispersal out of the GCFR has likely enriched cheilanthoid diversity in the Afro‐Madagascan region.

The first fossil record of endemic murid rodents from the Philippines: A late Pleistocene cave fauna from northern Luzon

Excavations in Callao Cave, in the lowland (ca. 85 m elevation) Cagayan River Valley of northeastern Luzon, Philippines, have produced the first fossils of any endemic genera of Philippine murid rodents. Three dentaries dated to the Late Pleistocene, between ca. 50,000 and 68,000 BP, are referred to the genera Batomys and Apomys; the former is a member of the endemic “Phloeomys Division” of Philippine murids, and the latter of the “Chrotomys Division,” also endemic to the Philippines. Batomys is currently known from five extant species from Luzon, Mindanao, and Dinagat islands; the two species known from Luzon differ in size and dental and mandibular morphology from the two fossil mandibles, and both occur only at elevations above 1350 m. Apomys is currently known from two subgenera on Luzon; the fossil is a member of the nominate subgenus, which contains two species on Luzon, one of which, Apomys microdon, is conspecific with one fossil. We hypothesize that the Batomys fossils represent a different species from the living taxa, but we do not name it due to the fragmentary nature of the specimens. These Apomys and Batomys represent the first fossil small mammals from the main body of the Philippine archipelago (east of Huxley's Line), and the Batomys are the first suspected extinct Pleistocene small mammal from the Philippines. The fossils indicate greater species richness and broader distributions than at present within this distinctive and diverse endemic radiation of mammals.

Molecular phylogeny of an endemic radiation of Cuban toads (Bufonidae: Peltophryne) based on mitochondrial and nuclear genes

AbstractAim In this study we present a molecular phylogenetic and phylogeographical analysis of Peltophryne (Anura: Bufonidae), an endemic genus of Antillean toads, to investigate the spatial and temporal origins of the genus, with particular focus on the eight Cuban species.Location Greater Antilles, with extensive sampling of the Cuban archipelago.Methods We obtained DNA sequence data from two mitochondrial genes, cytochrome c oxidase subunit I (COI) and ribosomal RNA (16S), for 124 toads representing all eight Cuban species, and combined this with published data from Hispaniola (one of three species) and Puerto Rico (one of one species) to establish a molecular phylogeny for Peltophryne. In addition, we explored the phylogeographical structure of widespread Cuban species. For a subset of 42 toads we also obtained DNA sequence data from two nuclear genes, recombination activator‐1 (RAG‐1) and chemokine receptor 4 (CXCR‐4). We combined our molecular data with published DNA sequences from a global sample of bufonid toads to place the spatial and temporal origins of Peltophryne in the Caribbean within a fuller geographical and phylogenetic context.Results All phylogenetic analyses supported the monophyly of West Indian toads. The ancestor of Peltophyrne diverged from its mainland source around the Eocene–Oligocene boundary, with a subsequent radiation across the Caribbean islands taking place during the Miocene. Cuban species are monophyletic with a basal split in the early–middle Miocene that separates extant small‐bodied from large‐bodied species. Extensive mitochondrial DNA (mtDNA) sampling within widespread Cuban species revealed contrasting phylogeographical patterns. Peltophryne taladai and P. empusa showed deeply divergent lineages, whereas no geographical structure was observed in the widespread P. peltocephala.Main conclusions Our timeline for Peltophryne diversification is consistent with a biogeographical model requiring no long‐distance overwater dispersal. Although confidence intervals on divergence time estimates are wide, the stem age of Peltophyrne coincides with the hypothesized GAARlandia landspan or archipelago, which may have connected South America briefly with the Antilles. The ages of Peltophryne for Puerto Rico, Hispaniola and Cuba are consistent with a recently proposed vicariance scenario for the region. Our molecular results support the recognition of all eight species in Cuba, and provide evidence of possible cryptic species.

Multiple cenozoic invasions of Africa by penguins (Aves, Sphenisciformes)

Africa hosts a single breeding species of penguin today, yet the fossil record indicates that a diverse array of now-extinct taxa once inhabited southern African coastlines. Here, we show that the African penguin fauna had a complex history involving multiple dispersals and extinctions. Phylogenetic analyses and biogeographic reconstructions incorporating new fossil material indicate that, contrary to previous hypotheses, the four Early Pliocene African penguin species do not represent an endemic radiation or direct ancestors of the living Spheniscus demersus (blackfooted penguin). A minimum of three dispersals to Africa, probably assisted by the eastward-flowing Antarctic Circumpolar and South Atlantic currents, occurred during the Late Cenozoic. As regional sea-level fall eliminated islands and reduced offshore breeding areas during the Pliocene, all but one penguin lineage ended in extinction, resulting in today's depleted fauna.

New adapiform primate of Old World affinities from the Devil’s Graveyard Formation of Texas

Most adapiform primates from North America are members of an endemic radiation of notharctines. North American notharctines flourished during the Early and early Middle Eocene, with only two genera persisting into the late Middle Eocene. Here we describe a new genus of adapiform primate from the Devil’s Graveyard Formation of Texas. Mescalerolemur horneri, gen. et sp. nov., is known only from the late Middle Eocene (Uintan) Purple Bench locality. Phylogenetic analyses reveal that Mescalerolemur is more closely related to Eurasian and African adapiforms than to North American notharctines. In this respect, M. horneri is similar to its sister taxon Mahgarita stevensi from the late Duchesnean of the Devil’s Graveyard Formation. The presence of both genera in the Big Bend region of Texas after notharctines had become locally extinct provides further evidence of faunal interchange between North America and East Asia during the middle Eocene. The fact that Mescalerolemur and Mahgarita are both unknown outside of Texas also supports prior hypotheses that low-latitude faunal assemblages in North America demonstrate increased endemism by the late middle Eocene.

Further evidence for old radiations originating at the northern edge of the Australian plate

With respect to Jonsson et al. (1) and their discussion of the geographic origin of basal lineages within the core Corvoidea, I would like to highlight relevant evidence from recent phylogenetic studies of other Australasian vertebrate lineages. These have identified at least five other lineages with distributions centered or restricted to the islands to the northern edge of the Australian plate and east of the Asian plate that potentially date back to at least the Miocence: Ceratobatrachid frogs (endemic radiation ≈30 Mya) (2), two lineages of blindsnakes [Acutothyphlops and Pacific Rhamphothyphlops (both endemic clades ≈20–30 Mya)] (3), and two lineages of skinks, Corucia (split from nearest relatives in Australia ≈20 Mya) and Tribolonotus (split from nearest relatives a very deep ≈50 Mya) (4).

Stable isotope composition of the Miocene Dinaride Lake System deduced from its endemic mollusc fauna

The aragonite shells of 55 mollusc specimens from the late Early and early Middle Miocene of two palaeolakes of the Dinaride Lake System (DLS) are analysed for their δ18O and δ13C signatures. The data set has a bimodal distribution with a prominent peak between −3 and −4‰ for both isotopes and a second much weaker peak at more depleted values of c. −9 to −7‰. Taxa with ‘heavy’ values are interpreted to represent the inhabitants of the shores or shallow areas of the lake. Depleted values are attributed to species preferring freshwater habitats of springs or small rivulets, thus representing the freshwater end-member. The overall rather high values in both stable isotopes result from a combination of evaporation effects and the influx of already isotopically heavy freshwater from the karstic catchment area. Thus, the DLS is interpreted as a closed freshwater system without marine influence but with enough contribution of freshwater to keep the oxygen values close to −5‰. Mean lake surface water temperatures, based on the δ18Oshell values, excluding the freshwater end-member taxa, range around roughly 19–21°C. Despite the problems in calculating these temperatures, the values are in agreement with mean annual air temperatures deduced from the palaeobotanic record by applying the Coexistence Approach method. The seasonal range was around 10–11°C and is mainly recorded in shells from lake settings. Taxa with freshwater end-member signatures lack this range due to the more stable temperature regime and less fluctuating dissolved inorganic carbon (DIC) pool. Congeneric species from the same stratigraphic horizon often display discrete but different isotope signatures. This fact suggests habitat segregation and might be a major factor for sympatric speciation and the endemic radiation within the mollusc fauna of the DLS.

Deep mtDNA subdivision within Linnean species in an endemic radiation of tiger beetles from New Zealand (genus Neocicindela)

The invertebrate fauna of New Zealand is of great interest as a geologically tractable model for the study of species diversification, but direct comparisons with closely related lineages elsewhere are lacking. Integrating population-level analyses with studies of taxonomy and clade diversification, we performed mtDNA analysis on Neocicindela (Cicindelidae, tiger beetles) for a broad sample of populations from 11 of 12 known species and 161 specimens (three loci, 1883 nucleotides), revealing 123 distinct haplotypes. Phylogenetic reconstruction recovered two main lineages, each composed of 5–6 Linnean species whose origin was dated to 6.66 and 7.26 Mya, while the Neocicindela stem group was placed at 10.82 ± 0.48 Mya. Species delimitation implementing a character-based (diagnostic) species concept recognized 19 species-level groups that were in general agreement with Linnean species but split some of these into mostly allopatric subgroups. Tree-based methods of species delimitation using a mixed Yule-coalescence model were inconclusive, and recognized 32–51 entities (including singletons), splitting existing species into up to 8 partially sympatric groups. These findings were different from patterns in the Australian sister genus Rivacindela, where character-based and tree-based methods were previously shown to produce highly congruent groupings. In Neocicindela, the pattern of mtDNA variation was characterized by high intra-population and intra-species haplotype divergence, the coexistence of divergent haplotypes in sympatry, and a poor correlation of genetic and geographic distance. These observations combined suggest a scenario of phylogeographic divergence and secondary contact driven by orogenetic and climatic changes of the Pleistocene/Pliocene. The complex evolutionary history of most species of Neocicindela due to the relative instability of the New Zealand biota resulted in populations of mixed ancestry but not in a general loss of genetic variation.