Central American Clade Research Articles

Phylogenetic relationships and systematics of the bamboo‐specialist Amaurospiza blue seedeaters

The Amaurospiza ‘seedeaters’ are bamboo‐specialized mixed strategists, most often found in bamboos in vegetative state, feeding on buds, shoots, petioles and insects. As bamboos die after flowering, birds may wander in search of live vegetative bamboo. The three currently recognized species of Amaurospiza are allopatrically distributed: the Blackish‐blue Seedeater Amaurospiza moesta in the Atlantic Forest of Argentina, Brazil and Paraguay, and in forest enclaves in the Cerrado; the recently described Carrizal Seedeater Amaurospiza carrizalensis known from a few localities in southeastern Venezuela; and the Blue Seedeater Amaurospiza concolor distributed patchily from Mexico to Peru. Three subspecies are recognized within A. concolor: relicta in southwest Mexico, concolor from southern Mexico to Panama and aequatorialis from southwest Colombia to northwest Peru. Full species status has been advocated for relicta and aequatorialis but evidence supporting their recognition is weak, while relicta was described in the monospecific genus Amaurospizopsis. Here we (1) test the monophyly of Amaurospiza, (2) reconstruct the phylogenetic relationships of all its constituent taxa using mitochondrial and nuclear markers, (3) re‐assess species limits in Amaurospiza with the aid of vocalizations and genetic and plumage data, and (4) discuss the link between bamboo life history, biogeographical patterns and extent of genetic differentiation. Amaurospiza was found to be monophyletic in both the ND2 and multilocus analyses. In the ND2 tree A. moesta and A. carrizalensis were sister to each other, A. concolor was found to be paraphyletic because aequatorialis was placed as sister to moesta–carrizalensis, and a clade including nominate concolor and relicta was sister to all the other taxa. The multilocus tree showed the same relationships, but lacked nuclear samples of relicta. Mean ND2 pairwise distance between concolor and aequatorialis (8.3%) was greater than that between moesta and carrizalensis (5.7%), while relicta diverged on average 1.0% from nominate concolor. The South American clade has more slender bills and white underwing coverts, while the Central American clade has thicker bills and bluish underwing coverts. All taxa exhibited typical Amaurospiza songs with quickly delivered, warbled, pure and fairly high‐pitched musical notes. Number of inflections/second exhibited a stepped pattern, with concolor and relicta on the lower end and carrizalensis, aequatorialis and moesta on the upper end. Similarly, moesta, carrizalensis and aequatorialis had overall more inflections per note than concolor and relicta. Linear discriminant analysis using nine acoustic variables correctly assigned all 62 songs to the correct taxon. Morphology, plumage, vocalizations and phylogenetic data indicate that aequatorialis should be afforded full species status as the Ecuadorian Seedeater (A. aequatorialis), suggest keeping relicta as a subspecies of A. concolor and support continued recognition of A. carrizalensis. Our data support merging Amaurospizopsis into Amaurospiza.

Insights into phylogenetic divergence of Dalbergia (Leguminosae: Dalbergiae) from Mexico and Central America

The pantropical genus Dalbergia includes more than 250 species. Phylogenetic studies of the group are scarce and have only included two or three species distributed in Mexico. We obtained herbarium samples of Mexican, Central American, and South American species (sourced from MEXU). In addition, sequences of GenBank accessions were used to complement the study. Using internal transcribed spacer (ITS), the matK and rbcL sequences from 384 accessions comprising species from America, Asia, and Africa were sampled to evaluate phylogenetic relationships of Mexican species and infrageneric classifications based on morphological data. Phylogenetic analyses suggest that the genus Dalbergia is monophyletic and originated in South America. The species distributed in Mexico are not a monophyletic clade but are divided into four clades with affinities to South American and Asian species clades. There is no correlation between geography and large-scale phylogeny. The estimated ages of the Mexican and Central American clades ranged from 11.32 Ma (Dalbergia granadillo clade) to 1.88 Ma (Dalbergia ecastaphyllum clade). Multiple long-distance dispersal events should be used to explain the current genus distribution.

The evolutionary history of vines in a neotropical biodiversity hotspot: Phylogenomics and biogeography of a large passion flower clade (Passiflora section Decaloba)

Because of their extraordinary flower and leaf morphology, passion flowers (Passifloraceae) have fascinated naturalists since their discovery. Within the large, diverse (600 species) genus Passiflora is an especially enigmatic and species-rich (120 spp.) subclade, Section Decaloba, which occurs in the Neotropics and has its center of diversity in Andean montane forests. A recent phylogenetic study of Passifloraceae showed that Section Decaloba was monophyletic, but was unable to resolve relationships within the clade, thus preventing inferences of evolutionary history and biogeography. The goal of this study was to elucidate the phylogeny and biogeography of Section Decaloba. We sampled 206 accessions representing 91 of the ~ 120 known species in section Decaloba and four outgroups, with samples derived predominantly from herbarium specimens. We generated DNA sequences using a high-throughput DNA sequencing technique called 2b-RAD, reconstructed the phylogeny, and conducted ancestral area reconstructions to infer the biogeographic history of the group. We recovered predominantly well-supported trees in which species were grouped into two main clades: 1) the Central American clade, within which the majority of nodes well supported and species were monophyletic and 2) the South American clade, a large clade that showed overall lower resolution and included several polyphyletic species and species complexes that need additional research. RASP analysis showed that section Decaloba originated in Central America around 10.4 Ma, and then dispersed to South America, the Greater Antilles, and the Bahamas. The South American clade diversified in the Northern Andes and then dispersed to the rest of South America, and Lesser Antilles. Results suggest that both long-distance dispersal and colonization of newly available habitats (i.e., in the Andes) likely promoted diversification of this clade. This study also illustrates how using herbarium specimens and a RAD-seq approach can produce phylogenies for broadly distributed, highly diverse, and poorly accessible groups of plants where field collections would be unfeasible.

Phylogenetics of the genus Sechium P. Brown: A review

The Sechium P. Br. genus composed of 11 species, which originated from the mountainous regions of Mesoamerica, have been domesticated and diversified. These species are clustered in two large groups: the Mexican clade and the Central American clade. Morphological and molecular studies have shown that species of the Mexican clade are formed through interspecific hybridizations and genetic flow, with the exception of S. mexicanum, which is strongly linked to the genus Sicyos. The objective of this review was to analyze the phylogenetics of Sechium based on morphological and molecular studies, which contributed to taxonomic knowledge and utilization, thereby favoring its conservation and improvement. The Central American clade is well supported with molecular data, but not so with morphological data. The species in this clade were geographically isolated and endemic. S. edule and S. tacaco are exploited species in the agricultural and industrial sectors, and both have an extensive genetic and phenotypic diversity that has allowed them to diversify and expand into different ecological niches. Finally, the Central American species of Sechium thrive in adverse environments of temperatures of mesophyll forest and high relative humidity, with characteristics that can give resistance to frosts and phytopathogenic agents, as well as cultivated species of this genus.

A New Section of Anthurium: Section Cordato-punctatum (Araceae), Restricted to Central America

Molecular studies have recently shown that a predominantly Mexican clade of Anthurium Schott species with ovate-cordate to ovate-sagittate leaf blades with glandular punctations on the lower (abaxial) surface is distinct from all other groups of Anthurium. This new section, Cordato-punctatum Croat & Carlsen, is one of three sections of Anthurium essentially restricted to Central America, and it contains six taxa. In this article, we describe and typify this new section, characterize its morphology, compare it to other Central American clades, and provide a current species list with geographic distributions.

A new giant velvet worm from Costa Rica suggests absence of the genus Peripatus (Onychophora: Peripatidae) in Central America

Introduction: Neotropical onychophoran taxonomy and diversity has been poorly investigated. Recent studies have discovered problems in species classification: they have questioned the accepted genera and the actual number of species. This is true in Costa Rica, where several unidentified species have been reported. Objective: The objective of this investigation was to evaluate the occurrence of the accepted genera in this country, and to describe a new genus and species from Central America. Methods: In 2017, we collected one onychophoran in the Keköldi Indigenous Reserve in Talamanca, Limón, Costa Rica. The specimen gave birth to several offspring. Therefore, seven organisms were analyzed. Light microscopy was used to observe the gross morphology in all samples. The detailed morphology was studied in the biggest specimen with scanning electron microscopy; after that, we performed a phylogenetic analysis with the corresponding sequence of COI. Results: According to our results, a new genus and species of giant onychophoran was found. The genus was identified by its giant size, apical piece of seven scale ranks, large conical primary papillae, dorso-median furrow flanked by two-three accessory papillae, the absence of hyaline organs and a marked sexual dimorphism with respect to the number of legs. The new species presents a particular head pattern, as well as novel structures like cephalic papillae, accessory papillae with rudimentary apical pieces, and a lack of antennal chemoreceptors. Phylogenetic analysis rendered our genus as monophyletic and includes Peripatus solorzanoi, which is grouped within the Central American clade. As our species is clustered inside the Costa Rica-Panamanian group, it is not related to the Caribbean Island nor Guyanan Shield samples, home of Epiperipatus and Peripatus respectively. Therefore, we suggest that those genera do not occur in Central America, and a new genus exists: Mongeperipatus, gen. nov. Conclusion: We concluded that Costa Rica is home to a diversity of undescribed onychophorans that requires specific studies to help clarify the taxonomy and evolutionary relationships of the group to justify their protection.

Geographic structure in two highly diverse lineages of Tillandsia (Bromeliaceae)

The Neotropical genus Tillandsia (Bromeliaceae) is an excellent model system for macroevolutionary and biogeographic studies owing to its remarkable species diversity (ca. 650 spp.) and varied morphological and ecological adaptations to epiphytic and saxicolous habitats. Recent phylogenetic studies have greatly improved our knowledge about generic limits and infrageneric classification of Tillandsia. These studies have identified two clades of Tillandsia characterized by a distinct geographic distribution: (i) a North and Central American clade that includes species from subgenus Tillandsia; and (ii) a central South American clade containing species from subgenera Aerobia, Anoplophytum, Diaphoranthema, and Phytarrhiza. Our study aimed to determine the size, composition, and potential geographic structure of these two clades within the context of a global phylogeny of Tillandsioideae. With the addition of 100 newly sequenced species to previous studies to cover the now ca. 30% of the known species diversity of Tillandsia, our analyses found both clades to be strongly supported, and revealed that their species richness is much greater than previously known. Ancestral area estimation suggests that most of the diversification of the first of these clades took place in North and Central America, whereas within the second, most of the migratory events occurred from the Andes to the Brazilian shield.

Recent advances on evolution of pollination systems and reproductive biology of Vanilloideae (Orchidaceae)

Vanilloideae as currently circumscribed comprises nine genera and two tribes: Vanilleae and Pogonieae. The pantropical genus Vanilla has been frequently assumed to be natural on the basis of its climbing habit and lateral inflorescences. However, the inclusion of the rare Dictyophyllaria dietschiana in phylogenetic analyses makes the genus Vanilla paraphyletic. Within Pogonieae, phylogenetic analyses show that inclusion of Pogoniopsis turns the tribe paraphyletic. All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae. Members of Pogonieae are pollinated by several groups of solitary and social bees, two pollination systems being recognized: reward-producing and deceptive. Molecular phylogeny suggests that the common ancestor to Pogonieae gave rise to two evolutionary lineages: one tropical with a condition of reward production; and one predominantly temperate-invading line with deceptive flowers. Reward-producing flowers characterize South and Central American clade (= Cleistes), while deceptive pollination is prominent in the clade including North American-Asiatic taxa plus Amazonian Duckeella. Species of “orchid bees” have been recorded as pollinators of the genus Vanilla (V. planifolia group and V. pompona group) in the Neotropics. In species of the V. pompona group, these bees are attracted by the fragrance of the flowers. Hummingbirds have been reported to pollinate some species of Vanilla. Vanilla insignis, V. odorata and V. planifolia are known to be pollinated through generalized food deception. Some species of Vanilla yield fruits through spontaneous self-pollination. This form of autogamy has been reported for V. griffithii, V. palmarum, V. planifolia, V. savannarum and V. bicolor. In Brazil, data on the pollination biology of Vanilla are scarce, but conclusive data are available for V. edwallii, which is pollinated by Epicharis (Apidae: Centridini). This species is rewardless, but male Epicharis are attracted to its flowers by their fragrance. Additionally, the Brazilian V. dubia and E. sclerophyllum are pollinated by bees. The mentum region of V. dubia and V. edwallii is dry, whereas that of E. sclerophyllum presents a small quantity of nectar. Flowers of E. sclerophyllum are scentless, while those of V. dubia are odoriferous. Vanilla dubia and V. edwallii are self-compatible and need a pollinator to yield fruits. In contrast, Epistephium sclerophyllum sets fruits through spontaneous self-pollination, but biotic pollination also occurs. Both species are primarily adapted to pollination by euglossine bees. Pollination by Euglossini seems to have evolved at least twice along the evolution of Vanilleae. Furthermore, shifts between rewarding and rewardless flowers and between autogamous and allogamous species have been reported among vanillas.

ZAMIA (ZAMIACEAE) PHENOLOGY IN A PHYLOGENETIC CONTEXT: DOES IN SITU REPRODUCTIVE TIMING CORRELATE WITH ANCESTRY?

The Cycadales are a group of significant global conservation concern and have the highest extinction risk of all seed plants. Understanding the synchronisation of reproductive phenology of Cycadales may be useful for conservation by enabling the targeting of pollen and seed collection from wild populations and identifying the window of fertilisation to aid in the cultivation of Cycadales. Phenological data for 11 species of Zamia were gathered from herbarium specimens. Four phenological characters were coded with monthly character states. DNA was isolated and sequenced for 26S, CAB, NEEDLY, matK and rbcL, and a simultaneous phylogenetic analysis of phenology and DNA sequence data was carried out. Three major clades were recovered: a Caribbean clade, a Central American clade and a South American clade. Eight species showed statistically significant synchronisation in microsporangiate and ovulate phenological phases, indicating the time of fertilisation. Close reproductive synchronisation was consistently observed throughout the Caribbean clade (statistically significant in four of five species) but was less consistent in the Central American clade (statistically significant in one of two species) and South American clade (statistically significant in three of four species). Ultimately, phenology is shown to be a potential driver of speciation in some clades of Zamia and in others to be a potential barrier to hybridisation.

Complex niche divergence underlies lineage diversification in Oophaga poison frogs

AbstractAimDespite the incredible diversity of lowland tropical rain forests, we still have limited understanding of the drivers of speciation in these ecoregions. Here, we investigated the relative contribution of geographical and environmental factors to the diversification of a Neotropical genus of poison frogs (Oophaga).LocationCentral and South America, including regions from southern Nicaragua to northern Ecuador.MethodsWe generated gene genealogies (12S, 16S, COI, CytB and tRNA‐val, SIAH1, H3 and Rag1) and used species phylogenetic methods (MDC and *beast) to generate a robust phylogeny of Oophaga frogs. Then, we combined the resulting phylogenetic hypothesis with detailed geographical data and environmental niche modelling (ENM) to test the role of geographical isolation, climatic niche divergence and altitudinal gradients.ResultsGene genealogies were discordant and did not show exclusive genealogical patterns; however, species tree resolved the phylogenetic relationship among Oophaga species with strong node support (> 0.9 ML/BPP). Geographical ranges showed little overlap between distantly related species. However, within the South American and Central American clades, sister taxa showed substantially overlapping ranges. Analyses of ecological disparity (DTT) indicated a departure from a neutral (Brownian) model of evolution, and age‐range correlations, predicted niche occupancy profiles, and Seeva analyses showed that different species tend to evolve under different potential climatic niches.Main conclusionsOophaga frogs originated in Central America and reached South America after the closure of the Panama Isthmus. The South‐ and Central‐American clades of this genus have convergently evolved to similar patterns of geographical distribution and niche occupancy. Within clades, sister taxa showed parapatric distributions replacing each other along elevational gradients as predicted by the models of divergence along continuous ecological gradients. Accordingly, we found strong shifts in climatic niches throughout the history of these two clades. However, the largest niche shifts seem to post‐date the final elevation of the Talamanca and northern Andes. Overall, our data suggest that speciation along climatic gradients on a structured landscape has been a major evolutionary force behind the diversification of Oophaga poison frogs.

A Multilocus Molecular Phylogeny forChaetostomaClade Genera and Species with a Review ofChaetostoma(Siluriformes: Loricariidae) from the Central Andes

The rubbernose-pleco genus Chaetostoma comprises 47 currently valid and many undescribed species distributed along Atlantic and Pacific slopes of the Andes Mountains from Panama to southern Peru, the Coastal Mountains of Venezuela, and drainages of the Guiana and Brazilian shields. We present a five-locus molecular phylogeny for 21 described and six undescribed species of Chaetostoma spanning the geographic range of the genus. Bayesian and maximum likelihood analyses found Chaetostoma to be well supported as monophyletic and sister to a clade of central and northern Andean genera that have also been hypothesized to be closely related based on morphology (i.e., Andeancistrus, Cordylancistrus, Dolichancistrus, Leptoancistrus, and Transancistrus). Species of Chaetostoma were divided into a trichotomy consisting of: a Pacific Coast, Central American, Magdalena Basin, Lake Valencia, and Guiana Shield clade; a western Orinoco, Lake Maracaibo, and Lake Valencia clade; and a widespread upper Amazon/Orinoco clade inclusive of a single species on the Brazilian Shield. We also conducted a systematic review of species from the central Andes of northern Peru and Ecuador. Based on our phylogenetic results and direct examination of historical and recently collected type and non-type material, we describe two new species of Chaetostoma (C. bifurcum, from the Pacific Coast, and C. trimaculineum, from the Atlantic Slope), redescribe four species (C. breve, C. carrioni, C. dermorhynchum, and C. microps, all from the Atlantic Slope), transfer four species from Chaetostoma to Ancistrus and find two species to be junior synonyms.

Derivation of the freshwater fish fauna of Central America revisited: Myers's hypothesis in the twenty-first century.

Although attempts to understand Central American freshwater fish provincialism date to the 1960s, early efforts lacked the wealth of distributional data now available. Biogeographic work on Central American freshwater fishes has been largely descriptive and regional, and lacked a broader synthesis. Here we use parsimony analysis of endemicity (PAE) to elucidate faunistic relationships between major drainages and to delineate areas of endemism. We then perform a Brooks parsimony analysis (BPA) on the resulting areas. The PAE recovered a primary division between four Pacific and six Atlantic slope areas of endemism. In contrast, the BPA recovered two Central American geographic clades, one sharing a history with North America and the other with South America. Fish diversity is uneven across Central America, with greater diversity in areas adjacent to the more species-rich regions of North and South America. In northern and nuclear Central America, the paucity of ostariophysan freshwater fishes such as catfishes and characins (groups that dominate adjacent regions) contrasts with high species richness of poeciliids and cichlids. Results of this study are consistent with Myer's hypothesis that poeciliids and cichlids dispersed to Northern or Nuclear Middle America early in the Cenozoic, long before the Plio-Pleistocene rise of the Isthmus of Panama.

A Single Early Introduction of HIV-1 Subtype B into Central America Accounts for Most Current Cases

Human immunodeficiency virus type 1 (HIV-1) variants show considerable geographical separation across the world, but there is limited information from Central America. We provide the first detailed investigation of the genetic diversity and molecular epidemiology of HIV-1 in six Central American countries. Phylogenetic analysis was performed on 625 HIV-1 pol gene sequences collected between 2002 and 2010 in Honduras, El Salvador, Nicaragua, Costa Rica, Panama, and Belize. Published sequences from neighboring countries (n = 57) and the rest of the world (n = 740) were included as controls. Maximum likelihood methods were used to explore phylogenetic relationships. Bayesian coalescence-based methods were used to time HIV-1 introductions. Nearly all (98.9%) Central American sequences were of subtype B. Phylogenetic analysis revealed that 437 (70%) sequences clustered within five significantly supported monophyletic clades formed essentially by Central American sequences. One clade contained 386 (62%) sequences from all six countries; the other four clades were smaller and more country specific, suggesting discrete subepidemics. The existence of one large well-supported Central American clade provides evidence that a single introduction of HIV-1 subtype B in Central America accounts for most current cases. An introduction during the early phase of the HIV-1 pandemic may explain its epidemiological success. Moreover, the smaller clades suggest a subsequent regional spread related to specific transmission networks within each country.

Pollination systems in Pogonieae (Orchidaceae: Vanilloideae): A hypothesis of evolution among reward and rewardless flowers

The tribe Pogonieae of Vanilloideae (Orchidaceae) consists of six genera, including Pogoniopsis, a myco-heterotrophic taxon with morphological characteristics distinct from the remaining of the tribe. A hypothesis about the phylogeny of the tribe was inferred, involving all currently recognized genera, based on isolated and combined sequence data of 5.8S, 18S and 26S (nrDNA) regions using parsimony and Bayesian analyses. Phylogenetic analyses show that inclusion of Pogoniopsis turns the tribe Pogonieae paraphyletic. All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae. The pantropical Vanilla is monophyletic if Dictyophyllaria is assumed as synonym of Vanilla. Members of Pogonieae are pollinated by several groups of solitary and social bees, two pollination systems being recognized: reward-producing and deceptive. The molecular phylogeny suggests that ancestrals related to Pogonieae gave rise to two evolutionary lines: a tropical one with reward production of flowers, and a predominantly temperate regions invading line with deceptive flowers. Reward-producing flowers characterize the South and Central American clade (=Cleistes), while deceptive pollination is prominent in the clade that includes North American-Asiatic taxa plus the Amazonian genus Duckeella.

Phylogenetic reassessment of the Exophthalmus genus complex (Curculionidae: Entiminae: Eustylini, Geonemini)

The monophyly of the Neotropical entimine weevil genus Exophthalmus Schoenherr, 1823 (Curculionidae: Entiminae: Eustylini Lacordaire) is reassessed. Exophthalmus presently includes more than 80 species, approximately half of which are restricted to either the Caribbean archipelago or the continental Neotropics. The taxonomic composition and position of Exophthalmus have been subject to longstanding disagreements; in particular, authors have questioned the relationship of Exophthalmus to other Caribbean genera such as Diaprepes Schoenherr, 1834 (Eustylini) and Lachnopus Schoenherr, 1840 (Geonemini Gistel), as well as to the speciose Central and South American genera Compsus Schoenherr, 1823, Eustylus Schoenherr, 1842, and Exorides Pascoe, 1881 (all Eustylini), among others. The present study scrutinizes these traditional perspectives, based on a cladistic analysis of 143 adult morphological characters and 90 species, representing 30 genera and seven tribes of Neotropical entimine weevils. The character matrix yielded eight most-parsimonious cladograms (length = 239 steps; consistency index = 66; retention index = 91), with mixed clade support that remains particularly wanting for some of the deeper in-group divergences. The strict consensus supports the existence of a paraphyletic Geonemini ‘grade’ that includes Lachnopus and related Caribbean genera such as Apotomoderes Dejean, 1834, followed by a monophyletic Eustylini in-group clade. Within the latter, a monophyletic South American Eustylini clade - including Compsus, Eustylus, Exorides, and related genera - is sister to a major clade that contains a ‘grade’ of heterogeneous and often misclassified Caribbean members of the Eustylini, Geonemini (Tetrabothynus Labram & Imhoff, 1852 and Tropirhinus Schoenherr, 1823), and Tanymecini Lacordaire (Pachnaeus Schoenherr, 1826), as well as two major clades: one with the majority of Central American Exophthalmus species, and the other with most Caribbean members of Exophthalmus. The Central American Exophthalmus clade is paraphyletic with respect to Chauliopleurus Champion, 1911 (Geonemini) and Rhinospathe Chevrolat, 1878 (Phyllobiini Schoenherr). The Caribbean clade, in turn, contains two subclades: i.e. (1) the Greater Antillean Exophthalmus s.s. clade, including the type species Exophthalmus quadrivittatus (Olivier, 1807); and (2) the primarily Lesser Antillean Diaprepes. The latter genus is therefore nested within Central American and Caribbean species of a highly paraphyletic Exophthalmus, yet may be rendered monophyletic if several Lesser Antillean Exophthalmus species are (re-)assigned to Diaprepes. The results thus provide a suitable basis for a revision of all Exophthalmus species, and furthermore suggest that historical biographic factors, including colonization via temporary continental Neotropics-to-Caribbean land connections, were important in the evolution of major eustyline lineages. Based on these preliminary insights, the following taxonomic and nomenclatural adjustments are made. Compsoricus gen. nov. is erected to accommodate two Puerto Rican species erroneously assigned to Compsus: i.e. the herein designated type species Compsoricus maricao comb. nov. and Compsoricus luquillo comb. nov. Eustylus dentipes comb. nov. is transferred from Compsus. Diaprepes marginicollis Chevrolat, 1880 is reinstated from synonymy under Exophthalmus. Lastly, the following five transfers are proposed: (1) Chauliopleurus Champion, 1911, from Geonemini to Eustylini; (2) Tetrabothynus Labram & Imhoff, 1852, from Geonemini to Eustylini; (3) Tropirhinus Schoenherr, 1823, from Geonemini to Eustylini; (4) Rhinospathe Chevrolat, 1878, from Phyllobiini to Eustylini; and (5) Pachnaeus Schoenherr, 1826, from Tanymecini to Eustylini.

The extraordinary journey of Peperomia subgenus Tildenia (Piperaceae): insights into diversification and colonization patterns from its cradle in Peru to the Trans-Mexican Volcanic Belt

Aim Peperomia subgenus Tildenia consists of c. 60 species growing in seasonal habitats of Neotropical mountain areas from Mexico to Argentina. The subgenus can be split geographically, with almost equal diversity in the Northern Hemisphere (centred in Mexico and Guatemala) and in the Southern Hemisphere (centred in Peru and Bolivia). Only a few species are known from a limited number of localities between these two hotspots. As such, Tildenia is an ideal candidate with which to test time, direction and mode of migration of high mountain taxa against the background of the ‘Great American Biotic Interchange’. Location The Andes with focus on the Central Andes, and the Mexican mountain chains, especially the Trans-Mexican Volcanic Belt. Methods To elucidate the spatio-temporal origin, subsequent colonization and radiation of Tildenia, we combine Bayesian phylogenetics based on the chloroplast trnK–matK–psbA region, georeferenced distribution data, and fossil calibrated molecular dating approaches using both penalized likelihood and relaxed phylogenetics. Reconstruction of the ancestral distribution area was performed using dispersal–vicariance analysis and dispersal–extinction–cladogenesis. Results Peperomia subgenus Tildenia is subdivided into six Andean clades and one Mexican and Central American clade originating from a north/central Peruvian ancestor. Molecular dating approaches converge on a stem age of c. 38 Ma for Tildenia and a mostly Miocene diversification and colonization. Main conclusions We detect a strong correlation between diversification of Tildenia and orogenetic events in the respective distribution centres. In the Andes, distribution was influenced by the Altiplano–Eastern Cordillera System as well as the Amotape-Huancabamba Zone, where the latter serves as both migration barrier and migration bridge for different clades. In contrast to most studies of high-elevation taxa, we provide support for a south–north colonization towards Central America and Mexico, and provide additional, independent evidence for the latest view on the timing of the Great American Biotic Interchange. In Mexico, the Trans-Mexican Volcanic Belt has played a major role in more recent radiations together with climatic oscillation and the formation of refugia.

Assessing the molecular phylogeny of a near extinct group of vertebrates: the Neotropical harlequin frogs (Bufonidae; Atelopus)

Neotropical harlequin frogs, Atelopus, are a species-rich bufonid group. Atelopus monophyly has been suggested but intergeneric, interspecific and intraspecific relationships are poorly understood. One reason is that morphological characters of harlequin frogs are often difficult to interpret, making species delimitations difficult. Molecular analyses (DNA barcoding, phylogeny) may be helpful but sampling is hampered as most of the more than 100 Atelopus species have undergone severe population declines and many are possibly extinct. We processed mitochondrial DNA (12S and 16S rRNA) of 28 available ingroup samples from a large portion of the genus’ geographic range (Bayesian Inference, Maximum Likelihood). Our samples constitute a monophyletic unit, which is sister to other bufonid genera studied including the Andean genus Osornophryne. In contrast to previous morphological studies, our results suggest that Osornophryne is neither sister to Atelopus nor nested within it. Within Atelopus, we note two major clades with well supported subclades, one Amazonian–Guianan Clade (Flavescens-spumarius Clade plus Tricolor Clade) and an Andean–Chocó–Central American Clade (Varius Clade plus all other Atelopus). The first mentioned includes all species that possess a middle ear (i.e. stapes) except for A. seminiferus lacking it (like all remaining Atelopus). Previously proposed species groups based on frog-like versus toad-like overall appearance (i.e. Longirostris and Ignescens Groups) or phalangeal reduction in the thumb (i.e. Flavescens Group) are not monophyletic in our phylogeny, thus characters used to define them are not considered synapomorphies. We show that genetic divergence can be high between species belonging to different clades, in spite of their phenetic similarity (e.g. A. pulcher, Atelopus sp. 2). On the other hand, within the same clade, colour can vary tremendously, while genetic divergence is low (e.g. A. flavescens and allies). These observations demonstrate that Atelopus taxonomy is complicated and that an integrative approach is required before ‘splitting’ or ‘lumping’ nominal species.

Notes on Swartzia (Leguminosae) in Central America preliminary to the Flora Mesoamericana, with descriptions of two new species from Costa Rica

In preparation of a treatment of Swartzia (Leguminosae) for the Flora Mesoamericana, recent updates to the taxonomy of the genus in Central America are discussed, and two new species from the Pacific slope and lowlands of central and southern Costa Rica are described and illustrated. One of them, S. picramnioides, is a member of the section Possira and is closely related to S. standleyi of Guatemala and Belize and to the South American species S. myrtifolia. The other, S. zeledonensis, belongs to the Central American apetalous clade of section Terminales. It is probably most closely related to the Panamanian species, S. nuda. We conclude that Swartzia is represented in Mexico and Central America by 14 species and provide a key for their identification.

Chapter 8: Phylogeography and Adaptive Plumage Evolution in Central American Subspecies of the Slate-Throated Redstart (Myioborus Miniatus)

Abstract The Slate-throated Redstart (Myioborus miniatus) is a common warbler of montane forests from northern Mexico to Argentina. We examined phylogenetic structure and plumage pattern in relation to subspecific taxonomy across the broad geographic range of this species. Phylogenetic analysis of two complete mitochondrial protein-coding genes (subunits 2 and 3 of NADH dehydrogenase) from 36 individuals, representing 10 of the 12 subspecies, revealed four clades, three of which showed general concordance with subspecific classification. However, in a Central American clade, four subspecies (hellmayri, connectens, comptus, and aurantiacus) could not be resolved by the molecular phylogenetic analysis, even though populations of hellmayri and connectens are currently geographically isolated from those of comptus and aurantiacus by the Nicaraguan lowlands. The genetic homogeneity within this clade suggests a late Pleistocene range expansion at a time when today's montane forest types existed at lower elevati...

Multilocus phylogeny and rapid radiations in Neotropical cichlid fishes (Perciformes: Cichlidae: Cichlinae)

Neotropical cichlid fishes comprise approximately 60 genera and at least 600 species, but despite this diversity, their phylogeny is only partially understood, which limits taxonomic, ecological and evolutionary research. We report the largest molecular phylogeny of Neotropical cichlids produced to date, combining data from three mitochondrial and two nuclear markers for 57 named genera and 154 species from South and Central America. Neotropical cichlids (subfamily Cichlinae) were strongly monophyletic and were grouped into two main clades in which the genera Retroculus (Tribe Retroculini) and Cichla (Cichlini) were sister to a monophyletic group containing all other lineages. This group included the tribes Chaetobranchini, Astronotini, Geophagini, Cichlasomatini and Heroini. Topological comparisons with previously published hypotheses indicated that our results are congruent with recent analyses of the tribe Cichlasomatini, but significantly more likely than published hypotheses for Geophagini, Heroini and the entire Cichlinae. Improved resolution and support are attributed to increased taxon sampling and to the addition of taxa never before included in phylogenetic analyses. Geophagini included two major subclades congruent with our own previous findings but more strongly supported; we also found a new and strongly supported sister-group relationship between Guianacara and Mazarunia. Cichlasomatini relationships were similar to recently proposed topologies, but contrastingly, we found a monophyletic Cichlasoma and support for a monophyletic grouping of the Aequidens diadema and A. tetramerus groups. Three basal South American Heroini lineages were recovered: ( Hypselecara + Hoplarchus), Pterophyllum, and a grouping we refer to as mesonautines. Three other South American clades, caquetaines, Australoheros and the ‘ Cichlasoma’ festae group, were nested within Central American clades. Most Heroini diversity was divided into two relatively well-supported large groups: the Southern Central American Clade, including clades herein referred to as nandopsines, caquetaines and amphilophines, and the Northern Central American Clade, including astatheroines, tomocichlines and herichthyines. Some of these groups have been previously identified, but often with different taxonomic compositions. Further resolution of Neotropical cichlid relationships, especially within the large amphilophine clade of Heroini, will require additional phylogenetic analysis. Nevertheless, the topology from this study provides a robust phylogenetic framework for studying evolutionary diversification in Neotropical cichlids. Significantly-short branches at the base of Geophagini and Heroini are compatible with early bursts of divergence that are characteristic of adaptive radiations. This pattern suggests diversification of Neotropical cichlid genera occurred rapidly, with subsequent convergent, adaptive ecomorphological diversification among and within South and Central American clades.