Tropical Asian species show that the Old World clade of ‘spiny solanums’ (Solanum subgenus Leptostemonum pro parte: Solanaceae) is not monophyletic

The tropical Asian taxa of the species‐rich genus Solanum (Solanaceae) have been less well studied than their highly diverse New World relatives. Most of these tropical Asian species, including the cultivated brinjal eggplant/aubergine and its wild progenitor, are part of the largest monophyletic Solanum lineage, the ‘spiny solanums’ (subgenus Leptostemonum or the Leptostemonum clade). Here we present the first phylogenetic analysis of spiny solanums that includes broad sampling of the tropical Asian species, with 42 of the 56 currently recognized species represented. Two nuclear and three plastid regions [internal transcribed spacer (ITS), waxy, ndhF‐rpL32, trnS‐trnG and trnT‐trnF] were amplified and used to reconstruct phylogenetic relationships using maximum likelihood and Bayesian methods. Our analyses show that Old World spiny solanums do not resolve in a single clade, but are part of three unrelated lineages, suggesting at least three independent introductions from the New World. We identify and describe several monophyletic groups in Old World solanums that have not been previously recognized. Some of these lineages are coherent in terms of morphology and geography, whereas others show considerable morphological variation and enigmatic distribution patterns. Tropical Asia occupies a key position in the biogeography of Old World spiny solanums, with tropical Asian taxa resolved as the closest relatives of diverse groups of species from Australia and Africa.     

Phylogeny,host association and biogeographical patterns in the diverse millipede‐parasitoid genus Myriophora Brown (Diptera: Phoridae)

Myriophora is the most species‐rich group of parasitoids that attack toxic, chemically defended millipedes in the superorder Juliformia and order Polydesmida—a resource that few insect predators and parasitoids are able to exploit. Worldwide, there are an estimated 200 species of Myriophora, with the majority of the diversity centred in the Neotropical region. The phylogeny of Myriophora is unknown, biogeographical patterns are not documented, and known host associations have not been assessed in a phylogenetic context. We provide the first phylogenetic study of the genus from a data set composed of 52 taxa primarily from the Neotropical region including 10 outgroups, 40 morphological characters, and molecular data from three mitochondrial (16S, COI and ND1) and one nuclear marker (AK). We find that Myriophora dispersed from the New World to the Old World in a single event before subsequently spreading to the Afrotropical region. The ancestral hosts reconstructed for Myriophora are the benzoquinone‐producing Juliformia, and this association has been retained in the Old World clade. In the Neotropical region, Myriophora that are associated with cyanide‐producing polydesmidan millipedes are confined to a single clade that shows remarkably little genetic variation between clearly morphologically diagnosable species.     

The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae)

A new species of conifer was recently discovered in northern Vietnam. In a preliminary phylogenetic analysis of morphological data a possible sister species, Chamaecyparis nootkatensis (D. Don) Spach, was identified; however, because of the presumed phylogenetic remoteness of these two species to the remainder of the Cupressaceae, a new genus-Xanthocyparis-was described to accommodate both species. Here an analysis of ITS (nrDNA), matK, and rbcL sequence data in combination with 58 informative morphological characters was aimed at testing the monophyly of the remainder of Chamaecyparis and evaluating the placement and monophyly of Xanthocyparis. Chamaecyparis, minus C. nootkatensis, was resolved as a monophyletic group, remote from Cupressus and Xanthocyparis. Cupressus, Juniperus, and Xanthocyparis formed a very highly supported monophyletic group. However, Cupressus was not monophyletic. Instead the Old World species sampled were resolved sister to a clade containing a monophyletic Juniperus, a monophyletic Xanthocyparis, and a clade of New World Cupressus species. If both species of Xanthocyparis are to be treated as members of the same genus, then due to the principal of priority they will have to be recognized in the genus Callitropsis. Research is continuing to resolve the status of New World and Old World Cupressus.     

Phylogenetic interrelationships of the barbets (Aves: Capitonidae) and toucans (Aves: Ramphastidae) based on morphology with comparisons to DNA-DNA hybridization

A phylogenetic analysis of the interrelationships of the barbets (Capitonidae) and the toucans (Aves: Ramphastidae, Superfamily Ramphastoidea) is presented. Thirty-two morphological characters from the literature and independent osteological observations were analysed. Character polarity was determined by outgroup comparison to the Picidae, Indicatoridae, Galbulidae, Bucconidae and Coraciiformes. Four alternative phylogenetic hypotheses were compared: (1) the overall most parsimonious morphological phylogeny, (2) the most parsimonious morphological phylogeny in which the capitonids and ramphastids were hypothesized as monophyletic sister groups, and (3) and (4) the most parsimonious hypotheses for the evolution of the morphological characters within two proposed DNA-DNA hybridization phylogenies of the ramphastoids. The analysis focused on the higher level relationships of ramphastids and capitonids and interrelationships among capitonid genera. Two cladistic analyses were performed using 26 phylogenetically informative characters, and the PAUP and CONTREE computer alogorithms. The most parsimonious morphological phylogeny required fewer character changes and had a lower consistency index than any of the alternative hypotheses but congruence between the most parsimonious phylogeny and the second, revised DNA-DNA hybridization hypothesis was very high. Based on these results the monophyly of the Capitonidae is rejected. The ramphastids and the Neotropical capitonids form a well corroborated clade within the pantropical ramphastoid radiation. Neither the African, Asian nor New World capitonids is monophyletic. The genus Trachyphonus is the sister group to all other capitonids and ramphastids. The sister group to the ramphastids is the genus Semnornis. The interrelationships of the Old World capitonids excluding Trachyphonus are not completely resolved by these morphological data but one of the alternative phylogenetic resolutions is presented as a preliminary hypothesis. The clades in this resolved phylogeny are diagnosed and the palaeontology and biogeography of the ramphastoids arc-reviewed in light of this new evidence. A phylogenetic classification is proposed in which the Capitonidae is rejected and the capitonids and ramphastids are placed in seven subfamilies of the Ramphastidae.     

Systematics of the genus Mayazomus (Arachnida: Schizomida): the relevance of using continuous characters and pedipalp setae patterns to schizomid phylogenetics

The schizomid genus Mayazomus Reddell & Cockendolpher, 1995, endemic to south‐eastern Mexico, currently comprises seven species. It was originally proposed to accommodate two species, from Chiapas and Tabasco. Recently, five additional species from Chiapas were described. The monophyly of the genus has never been tested using cladistic analysis. We undertook a phylogenetic analysis using the seven described species of Mayazomus as the ingroup, ten exemplar species representing the most similar New World hubbardiids as the outgroup, and one protoschizomid species to root the tree. The analysis was based on 130 morphological characters (continuous and discrete characters). The resulting topologies recovered Mayazomus as paraphyletic, with Heteronochrus estor Armas & Viquez, 2010, from Guatemala nested within the genus; therefore, we formally propose its synonymy herein. Mayazomus appears to be most closely related to Rowlandius Reddell & Cokendolpher, 1995, a South American genus. This contribution also provides new characters derived from the pedipalp setae with important phylogenetic information; as well as the implementation of morphometric ratios, as continuous characters, to partially codify the shape of the male flagellum. The relationships recovered amongst the outgroups used in this contribution are a reliable baseline for future analyses of the phylogeny of the New World schizomids.     

Molecular phylogeny of a cosmopolitan group of woodpeckers (genus Picoides) gased on COI and cyt b mitochondrial gene sequences.

Picoides is the largest genus of woodpeckers and member species are found on most major land masses. Current systematic arrangement of this group, based on morphological, behavioral, and plumage characters, suggests that New World species evolved from a single invasion by a Eurasian common ancestor and that all New World species form a monophyletic group. No clear link has ever been established between the relationships of Old World and New World species other than to infer that the most primitive species is Eurasian. This study employs DNA sequences for two protein-coding mitochondrial genes, cytochrome oxidase I and cytochrome b, to reconstruct phylogenetic relationships among all New World species and several Eurasian representatives of the genus Picoides. A well-resolved mitochondrial gene tree is in direct conflict with proposed species relationships based on nongenetic characters; monophyly among New World species is rejected, the evolution of New World species likely resulted from as many as three independent Eurasian invasions, and Picoides is paraphyletic with two other woodpecker genera, Veniliornis and Dendropicos. These results strongly suggest that this large, cosmopolitan genus is in need of systematic revision in order to reflect evolutionary history.     

Phylogenetic analysis of the New World Ptininae (Coleoptera: Bostrichoidea)

A phylogenetic analysis of the New World Ptininae (Anobiidae) was conducted with representatives of nine of ten New World genera, several Old World genera and seven more of the ten subfamilies of Anobiidae. One hundred and two characters (forty‐three multistate) from thirty‐four taxa were used. The single cladogram shows Ptininae as monophyletic and the sister group of the remaining Anobiidae, supporting their placement as subfamilies of a monophyletic Bostrichidae. Genus Niptus Boieldieu is polyphyletic supporting recognition of Pseudeurostus Heyden and the creation of a new genus to encompass the remaining New World species of Niptus. Flightlessness has evolved a minimum of three times within Ptininae and myrmecophily has probably evolved three times within just the New World taxa. The classifications of Ptininae and the remaining Anobiidae are examined and the evolution of feeding habits, myrmecophily and wing loss are discussed.     

Multiple nuclear genes stabilize the phylogenetic backbone of the genus Quercus

Phylogenetic relationships among 108 oak species (genus Quercus L.) were inferred using DNA sequences of six nuclear genes selected from the existing genomic resources of the genus. Previous phylogenetic reconstructions based on traditional molecular markers are inconclusive at the deeper nodes. Overall, weak phylogenetic signals were obtained for each individual gene analysis, but stronger signals were obtained when gene sequences were concatenated. Our data support the recognition of six major intrageneric groups Cyclobalanopsis, Cerris, Ilex, Quercus, Lobatae and Protobalanus. Our analyses provide resolution at deeper nodes but with moderate support and a more robust infrageneric classification within the two major clades, the ‘Old World Oaks’ (Cyclobalanopsis, Cerris, Ilex) and ‘New World Oaks’ (Quercus, Lobatae, Protobalanus). However, depending on outgroup choice, our analysis yielded two alternative placements of the Cyclobalanopsis clade within the genus Quercus. When Castanea Mill. was chosen as outgroup, our data suggested that the genus Quercus comprised two clades corresponding to two subgenera as traditionally recognized by Camus: subgenus Euquercus Hickel and Camus and subgenus Cyclobalanopsis Øersted (Schneider). However, when Notholithocarpus Manos, Cannon and S. Oh was chosen as an outgroup subgenus Cyclobalanopsis clustered with Cerris and Ilex groups to form the Old World clade. To assess the placement of the root, we complemented our dataset with published data of ITS and CRC sequences. Based on the concatenated eight gene sequences, the most likely root position is at the split between the ‘Old World Oaks’ and the ‘New World Oaks’, which is one of the alternative positions suggested by our six gene analysis. Using a dating approach, we inferred an Eocene age for the primary divergences in Quercus and a root age of about 50–55 Ma, which agrees with palaeobotanical evidence. Finally, irrespective of the outgroup choice, our data boost the topology within the New World clade, where (Protobalanus + Quercus) is a sister clade of Lobatae. Inferred divergence ages within this clade and the Cerris–Ilex clade are generally younger than could be expected from the fossil record, indicating that morphological differentiation pre-dates genetic isolation in this clade.     

Entomologically famous, evolutionarily unexplored: The first phylogeny of the lanternfly family Fulgoridae (Insecta: Hemiptera: Fulgoroidea)

Lanternflies (Insecta: Hemiptera: Fulgoridae) are frequently used as examples of unusual morphological evolution, with some species (such as the peanut-headed bug, Fulgora laternaria Linnaeus) also ubiquitously cited as icons of tropical insect biodiversity. Despite that entomological notoriety, the phylogeny of this charismatic planthopper family has never before been studied. Presented here are the results of a phylogenetic investigation of Fulgoridae based on DNA nucleotide sequence data from five genetic loci (18S rDNA, 28S rDNA, histone 3, wingless, and cytochrome oxidase I). The resulting topologies are used to test the higher classification of Fulgoridae, which is based primarily on characters associated with the curious head morphology of many included species. Analyses include a taxonomic sample of 69 fulgorid species representing 46 (of 110) genera, 10 (of 11) tribes, and all 8 currently recognized subfamilies. Results of this study: (1) demonstrate the need for a revised classification of Fulgoridae, particularly at the higher taxonomic levels; (2) suggest that the genus Zanna is excluded from a monophyletic Fulgoridae; (3) indicate that there have been multiple losses of the extended head process across fulgorid evolution, with what appears to be convergence (in shape and/or loss) in distantly related lineages; and (4) suggest two alternative biogeographic hypotheses to explain the distribution of extant Fulgoridae, with either an Old World origin and a single subsequent colonization of the New World, or a contemporaneous diversification of Old and New World lineages.     

Phylogenetic relationships of North American Antirrhinum (Veronicaceae)

Species of the genus Antirrhinum (Veronicaceae) provide excellent opportunities for research on plant evolution given their extensive morphological and ecological diversity. These opportunities are enhanced by genetic and developmental data from the model organism Antirrhinum majus. The genus Antirrhinum includes 15 New World species in section Saerorhinum and 21 Old World species in sections Antirrhinum and Orontium. Phylogenetic analyses of sequences of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA were conducted for 19 Antirrhinum species, including all species from the New World, and 13 related genera in the tribe Antirrhineae. These analyses confirm the monophyly of Antirrhinum given the inclusion of the small genus Mohavea and exclusion of A. cyathiferum. The New World species, all of which are tetraploid, form a clade that is weakly supported as sister to the Old World sect. Orontium. The Old World species in sect. Antirrhinum form a well-supported clade that is sister to the remainder of the genus. In addition, both molecular and morphological data are used in the most comprehensive effort to date focused on recovering the phylogenetic relationships among the extremely diverse species in section Saerorhinum.     

Chloroplast DNA restriction site variation in theVernonieae (Asteraceae), an initial appraisal of the relationship of New and Old World taxa and the monophyly ofVernonia

Chloroplast DNA restriction site variation was examined for 35 taxa in theVernonieae and four outgroup tribes, using 17 restriction enzymes mapped for ca. 900 restriction sites per species; 139 mutations were found to be phylogenetically informative. Phylogenetic trees were constructed using Wagner and weighted parsimony, and evaluated by bootstrap and decay analyses. Relationships of Old and New World taxa indicate complex geographical relationships; there was no clear geographic separation by hemisphere. The relationships between Old and New World Vernonias found here support prior morphological analyses. The sister group to all New and most Old World taxa was composed of a small group of Old World species including yellow-flowered, trinervate-leaved species previously postulated to be basal in the tribe. The majority of both New and Old World taxa are derived from a lineage beginning with the monotypic genusStokesia, an endemic of the southeastern United States. The genusVernonia was also found to be paraphyletic within both the New and Old World. Available data do not support either the separation ofVernonia or the tribeVernonieae into geographically distinct lineages. The pattern of relationships within theVernonieae for taxa from North America, Asia, Africa, Central and South America is most similar to that of several other groups of both plants and animals with a boreotropical origin, rather than an origin in Gondwanaland. Such a pattern of distribution suggests more ancient vicariant events than are routinely postulated for theAsteraceae.     

Phylogenetic relationships in Nuphar (Nymphaeaceae): evidence from morphology,chloroplast DNA,and nuclear ribosomal DNA

The genus Nuphar consists of yellow-flowered waterlilies and is widely distributed in north-temperate bodies of water. Despite regular taxonomic evaluation of these plants, no explicit phylogenetic hypotheses have been proposed for the genus. We investigated phylogenetic relationships in Nuphar using morphology and sequences of the chloroplast gene matK and of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. Two major lineages within Nuphar are consistently resolved with the morphological and molecular data sets. One lineage comprises New World taxa and the other represents a primarily Old World lineage. Relationships within the major lineages were poorly resolved by morphology and ITS, yet certain relationships were elucidated by all analyses. Most notable is the strong support for a monophyletic lineage of dwarf taxa and the alliance of the North American N. microphylla with the Eurasian taxa. Minor discordance between the independent cladograms is accounted for by hybridization. The common taxonomic practice of uniting all North American and Eurasian taxa under one species is not supported phylogenetically.     

Phylogeny and historical biogeography of the paper wasp genus Polistes (Hymenoptera: Vespidae): implications for the overwintering hypothesis of social evolution

The phylogeny of the paper wasp genus Polistes is investigated using morphological and behavioural characters, as well as molecular data from six genes (COI, 12S, 16S, 28S, H3, and EF1‐α). The results are used to investigate the following evolutionary hypotheses about the genus: (i) that Polistes first evolved in Southeast Asia, (ii) that dispersal to the New World occurred only once, and (iii) that long‐term monogyny evolved as an adaptation to overwintering in a temperate climate. Optimization of distribution records on the recovered tree does not allow unambiguous reconstruction of the ancestral area of Polistes. While the results indicate that Polistes dispersed into the New World from Asia, South America is recovered as the ancestral area for all New World Polistes: Nearctic species groups evolved multiple times from this South American stock. The final tree topology suggests strongly that the genus first arose in a tropical environment, refuting the idea of monogyny as an overwintering adaptation.     

Bayesian mixed models and the phylogeny of pitvipers (Viperidae: Serpentes)

The subfamily Crotalinae (pitvipers) contains over 190 species of venomous snakes distributed in both the Old and New World. We incorporated an extensive sampling of taxa (including 28 of 29 genera), and sequences of four mitochondrial gene fragments (2.3kb) per individual, to estimate the phylogeny of pitvipers based on maximum parsimony and Bayesian phylogenetic methods. Our Bayesian analyses incorporated complex mixed models of nucleotide evolution that allocated independent models to various partitions of the dataset within combined analyses. We compared results of unpartitioned versus partitioned Bayesian analyses to investigate how much unpartitioned (versus partitioned) models were forced to compromise estimates of model parameters, and whether complex models substantially alter phylogenetic conclusions to the extent that they appear to extract more phylogenetic signal than simple models. Our results indicate that complex models do extract more phylogenetic signal from the data. We also address how differences in phylogenetic results (e.g., bipartition posterior probabilities) obtained from simple versus complex models may be interpreted in terms of relative credibility. Our estimates of pitviper phylogeny suggest that nearly all recently proposed generic reallocations appear valid, although certain Old and New World genera (Ovophis, Trimeresurus, and Bothrops) remain poly- or paraphyletic and require further taxonomic revision. While a majority of nodes were resolved, we could not confidently estimate the basal relationships among New World genera and which lineage of Old World species is most closely related to this New World group.     

New insight into the identification and molecular phylogeny of dagger nematodes of the genus Xiphinema (Nematoda: Longidoridae) with description of two new species

The genus Xiphinema constitutes a large group of about 260 species of plant‐ectoparasitic nematodes. The group is polyphagous and distributed almost worldwide. Some of the species of this genus damage agricultural crops by direct feeding on root cells as well as by transmitting nepoviruses. Species discrimination in Xiphinema is complicated by phenotypic plasticity leading to potential misidentification. We conducted nematode surveys in cultivated and natural environments in Spain from 2009 to 2012, from which we identified 20 populations of Xiphinema species morphologically close to the virus‐vector nematode species Xiphinema diversicaudatum, three apomictic populations tentatively identified as species from the complex Xiphinema aceri‐pyrenaicum group, and one population morphologically different from all others that is characterized by a female tail elongate to conical and absence of uterine differentiation. We developed comparative multivariate analyses for these related species by using morphological and morphometrical features together with molecular data from nuclear ribosomal DNA genes [D2‐D3 expansion segments of large ribosomal subunit 28S, internal transcribed spacer 1 (ITS1), and partial small ribosomal subunit (18S)]. The results of multivariate, molecular, and phylogenetic analysis confirmed the morphological hypotheses and allowed the delimitation and discrimination of two new species in the genus described herein as Xiphinema baetica sp. nov. and Xiphinema turdetanensis sp. nov. , and ten known species: Xiphinema adenohystherum, Xiphinema belmontense, Xiphinema cohni, Xiphinema coxi europaeum, Xiphinema gersoni, Xiphinema hispidum, Xiphinema italiae, Xiphinema lupini, Xiphinema nuragicum, and Xiphinema turcicum. Multivariate analyses based on quantitative and qualitative characters and phylogenetic relationships of Xiphinema spp. based on the three molecular ribosomal markers resulted in a partial consensus of these species grouping as nematode populations were maintained for the majority of morphospecies groups (e.g. morphospecies groups 5 and 6), but not in some others (e.g. position of Xiphinema granatum), demonstrating the usefulness of these analyses for helping in the diagnosis and identification of Xiphinema spp. The clade topology of phylogenetic trees of D2‐D3 and partial 18S regions in this study were congruent in supporting the polyphyletic status of some characters, such as the female tail shape and the degree of development of the genital system in species with both genital branches equally developed. This is the most complete phylogenetic study for Xiphinema non‐americanum‐group species. Agreement between phylogenetic trees and some morphological characters (uterine spines, pseudo‐Z organ, and tail shape) was tested by reconstruction of their histories on rDNA‐based trees using parsimony and Bayesian approaches. Thus, integrative taxonomy, based on the combination of multivariate, molecular analyses with morphology, constitutes a new insight into the identification of Xiphinema species. © 2013 The Linnean Society of London     

Evolution of blindness in scolopendromorph centipedes (Chilopoda: Scolopendromorpha): insight from an expanded sampling of molecular data

Relative to its diversity (34 genera, 700 species), Scolopendromorpha has been undersampled in molecular phylogenetic analyses compared with the other chilopod orders. Previous analyses based on morphology have not resolved several key controversies in systematics and evolutionary morphology unambiguously. Here we apply new molecular and morphological data to scolopendromorph phylogenetics, with a focus on the evolution of blindness. The taxonomic sample includes 19 genera, many lacking previous molecular data, and diverse, cosmopolitan genera of Scolopendridae are sampled by multiple species. Phylogenetic analysis with Direct Optimization used 94 morphological characters and ca. 4.5 kb of sequence data from two nuclear (18S and 28S rRNA) and two mitochondrial (16S rRNA and COI) loci. A single most‐parsimonious cladogram selected after sensitivity analyses resolves Scolopendromorpha as monophyletic, and divides it into a blind clade of three families (Plutoniumidae, Cryptopidae, Scolopocryptopidae) and its ocellate sister group, Scolopendridae. Some species‐rich, cosmopolitan genera (Cormocephalus, Otostigmus, Scolopendra) in Scolopendridae are non‐monophyletic, and in several instances (e.g. New and Old World Scolopendra) relationships are more congruent with geographical distributions than with traditional classifications. The tribe Asanadini is particularly subject to parameter‐sensitivity, nesting in the combined analysis within Scolopendrini but as sister to all other Scolopendrinae for molecular data alone. The total‐evidence tree unambiguously optimizes trunk segmentation: a 23‐segmented trunk has a single origin in the blind clade. © The Willi Hennig Society 2011.     

Tribal delimitation and phylogenetic relationships of Loteae and Coronilleae (Faboideae: Fabaceae) with special reference to Lotus: evidence from nuclear ribosomal ITS sequences

The temperate herbaceous tribes Loteae and Coronilleae have traditionally been regarded as taxonomically distinct entities. More recent morphological assessments, however, have challenged this view and suggest combining the two tribes under Loteae. Two key features used to distinguish the Coronilleae from Loteae include jointed fruits and branched root nodules. We evaluate the taxonomic utility of these characters using information derived from phylogenetic analyses of the internal transcribed spacers ITS1 + 2, and the intervening 5.8S region of nuclear ribosomal DNA. Results from this study show that neither the Loteae nor Coronilleae form individual monophyletic groups, and that key fruit and root nodule characters used to distinguish the Coronilleae are homoplastic. Given these data, we support the recognition of a single tribe, Loteae. We also find that Lotus, the largest and most morphologically complex genus in either tribe, is not monophyletic. Rather, it consists of two geographically distinct lineages, Old and New World, each of which are more closely related to other Loteae genera: Old World Lotus are more closely related to Old World Anthyllis, while New World Lotus show closer affinities to Old World Coronilla. These data also have important implications for the biogeography of New World Lotus: equally most parsimonious reconstructions suggest a complex scenario of intercontinental dispersals that involve not only Old World Lotus but Coronilla as well.     

Nectar-feeding bird and bat niches in two worlds: pantropical comparisons of vertebrate pollination systems

Aim We review several aspects of the structure of regional and local assemblages of nectar‐feeding birds and bats and their relationships with food plants to determine the extent to which evolutionary convergence has or has not occurred in the New and Old World tropics. Location Our review is pantropical in extent and also includes the subtropics of South Africa and eastern Australia. Within the tropics, it deals mostly with lowland forest habitats. Methods An extensive literature review was conducted to compile data bases on the regional and local species richness of nectar‐feeding birds and bats, pollinator sizes, morphology, and diets. Coefficients of variation (CVs) were used to quantify the morphospace occupied by the various families of pollinators. The extent to which plants have become evolutionarily specialized for vertebrate pollination was explored using several criteria: number and diversity of growth forms of plant families providing food for all the considered pollinator families; the most common flower morphologies visited by all the considered pollinator families; and the number of plant families that contain genera with both bird‐ and bat‐specialized species. Results Vertebrate pollinator assemblages in the New World tropics differ from those in the Old World in terms of their greater species richness, the greater morphological diversity of their most specialized taxa, and the greater degree of taxonomic and ecological diversity and morphological specialization of their food plants. Within the Old World tropics, Africa contains more specialized nectar‐feeding birds than Asia and Australasia; Old World nectar‐feeding bats are everywhere less specialized than their New World counterparts. Main conclusions We propose that two factors – phylogenetic history and spatio‐temporal predictability (STP) of flower resources – largely account for hemispheric and regional differences in the structure of vertebrate pollinator assemblages. Greater resource diversity and resource STP in the New World have favoured the radiation of small, hovering nectar‐feeding birds and bats into a variety of relatively specialized feeding niches. In contrast, reduced resource diversity and STP in aseasonal parts of Asia as well as in Australasia have favoured the evolution of larger, non‐hovering birds and bats with relatively generalized feeding niches. Tropical Africa more closely resembles the Neotropics than Southeast Asia and Australasia in terms of resource STP and in the niche structure of its nectar‐feeding birds but not its flower‐visiting bats.