American Genus Research Articles

Phylogenetic position of the relict South American genus Idiopyrgus Pilsbry, 1911 (Gastropoda, Truncatelloidea), with the description of two new cave species

Idiopyrgus is a relict genus of freshwater snails from Brazil traditionally classified in the family Pomatiopsidae. Herein, we use molecular data from newly acquired specimens to test that classification through Bayesian inference phylogenetic analysis. We conclude that Idiopyrgus belongs in the Gondwanan family Tomichiidae, together with the African genus Tomichia and the Australian genus Coxiella. Furthermore, we reassess currently synonymized genus- and species-level names in Idiopyrgus. The genera Hydracme and Aquidauania are considered synonymous with Idiopyrgus. The species I. brasiliensis and I. pilsbryi are restored as accepted species; I. walkeri is considered a taxon inquirendum. Two new species from caves in Bahia state are described herein: Idiopyrgus adamanteussp. nov. and Idiopyrgus minorsp. nov.

Psectrascelis senex sp. nov. (Coleoptera: Tenebrionidae), a new species from the southern Atacama Desert, Chile.

Psectrascelis Solier, 1836 is the most specious South American genus of Nycteliini, which inhabit arid and semiarid regions. Recent expeditions to the southern part of the Atacama Desert collected specimens of Psectrascelis which do not fit with any other described species belonging to this genus. These specimens are morphologically close to P. penai Kulzer, 1955 but the presence of carinae on the elytra easily differentiates this taxon from this mentioned above. Here, we analyzed external morphology, both male and female genitalia, and sequences from a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene with that of morphologically close species. Our study supports the description of Psectrascelis senex sp. nov. and suggests that P. senex sp. nov. is the sister species of P. penai.

Comparative repeatome analysis reveals new evidence on genome evolution in wild diploid Arachis (Fabaceae) species.

Opposing changes in the abundance of satellite DNA and long terminal repeat (LTR) retroelements are the main contributors to the variation in genome size and heterochromatin amount in Arachis diploids. The South American genus Arachis (Fabaceae) comprises 83 species organized in nine taxonomic sections. Among them, section Arachis is characterized by species with a wide genome and karyotype diversity. Such diversity is determined mainly by the amount and composition of repetitive DNA. Here we performed computational analysis on low coverage genome sequencing to infer the dynamics of changes in major repeat families that led to the differentiation of genomes in diploid species (x = 10) of genus Arachis, focusing on section Arachis. Estimated repeat content ranged from 62.50 to 71.68% of the genomes. Species with different genome composition tended to have different landscapes of repeated sequences. Athila family retrotransposons were the most abundant and variable lineage among Arachis repeatomes, with peaks of transpositional activity inferred at different times in the evolution of the species. Satellite DNAs (satDNAs) were less abundant, but differentially represented among species. High rates of evolution of an AT-rich superfamily of satDNAs led to the differential accumulation of heterochromatin in Arachis genomes. The relationship between genome size variation and the repetitive content is complex. However, largest genomes presented a higher accumulation of LTR elements and lower contents of satDNAs. In contrast, species with lowest genome sizes tended to accumulate satDNAs in detriment of LTR elements. Phylogenetic analysis based on repetitive DNA supported the genome arrangement of section Arachis. Altogether, our results provide the most comprehensive picture on the repeatome dynamics that led to the genome differentiation of Arachis species.

Insufficient Evidence for Multiple Species of Tyrannosaurus in the Latest Cretaceous of North America: A Comment on “The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus”

The Late Cretaceous dinosaur Tyrannosaurus rex was recently split into three species based on the premise that variation in the T. rex hypodigm is exceptional, indicating cryptic species and “robust” and “gracile” morphs. The morphs are based on proportional ratios throughout the skeleton. The species are claimed to be stratigraphically separate, with an early robust species followed by robust and gracile descendants. There are problems with the hypothesis: the taxon diagnoses are based on two features that overlap between the species; several skulls cannot be identified based on the diagnoses; proportional comparisons between Tyrannosaurus and other theropods are based on incomparable samples; the tooth data are problematic; the stratigraphic framework divides the Hell Creek Formation into thirds, without the stratigraphic position of each specimen, or independent age control showing the subdivisions are coeval over the entire geographic area; previous work found variation in T. rex, but it cannot be parsed into discrete categories. We tested for “gracile” and “robust” morphs by analyzing the femoral and tooth ratios that were published in the multiple species study using agglomerative hierarchical clustering. The results found that each set of ratios are explained by one cluster, showing that dimorphism is not supported. We tested for exceptional variation of the femoral ratio of Tyrannosaurus; we calculated the mean intraspecific robusticity for 112 species of living birds and 4 nonavian theropods. The results showed that the absolute variation in Tyrannosaurus is unexceptional and it does not indicate cryptic diversity. We conclude that “T. regina” and “T. imperator” are subjective junior synonyms of T. rex.

Revised Species Delimitation in the Giant Water Lily Genus Victoria (Nymphaeaceae) Confirms a New Species and Has Implications for Its Conservation.

Reliably documenting plant diversity is necessary to protect and sustainably benefit from it. At the heart of this documentation lie species concepts and the practical methods used to delimit taxa. Here, we apply a total-evidence, iterative methodology to delimit and document species in the South American genus Victoria (Nymphaeaceae). The systematics of Victoria has thus far been poorly characterized due to difficulty in attributing species identities to biological collections. This research gap stems from an absence of type material and biological collections, also the confused diagnosis of V. cruziana. With the goal of improving systematic knowledge of the genus, we compiled information from historical records, horticulture and geography and assembled a morphological dataset using citizen science and specimens from herbaria and living collections. Finally, we generated genomic data from a subset of these specimens. Morphological and geographical observations suggest four putative species, three of which are supported by nuclear population genomic and plastid phylogenomic inferences. We propose these three confirmed entities as robust species, where two correspond to the currently recognized V. amazonica and V. cruziana, the third being new to science, which we describe, diagnose and name here as V. boliviana Magdalena and L. T. Sm. Importantly, we identify new morphological and molecular characters which serve to distinguish the species and underpin their delimitations. Our study demonstrates how combining different types of character data into a heuristic, total-evidence approach can enhance the reliability with which biological diversity of morphologically challenging groups can be identified, documented and further studied.

The Malesian species of Dalechampia (Euphorbiaceae)

Dalechampia is a mainly South American genus of generally climbing shrubs with usually sharp stiff trichomes in some of the inflorescence parts. The bisexual inflorescences are very condensed and subtended by two, often showy, large bracts. The three pistillate flowers are separate from the staminate subinflorescence (both groups with their own bracts). The staminate subinflorescence contains groups of staminodial-like bractlets that provide resin for female bees or fragrance for male bees. In west Malesia (Sumatra and Java) one indigenous species is found, the climbing D. bidentata, and occasionally cultivars of the subshrub D. spathulata.

Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae).

Capsicum L. (tribe Capsiceae, Solanaceae) is an American genus distributed ranging from the southern United States of America to central Argentina and Brazil. The genus includes chili peppers, bell peppers, ajíes, habaneros, jalapeños, ulupicas and pimientos, well known for their economic importance around the globe. Within the Solanaceae, the genus can be recognised by its shrubby habit, actinomorphic flowers, distinctive truncate calyx with or without appendages, anthers opening by longitudinal slits, nectaries at the base of the ovary and the variously coloured and usually pungent fruits. The highest diversity of this genus is located along the northern and central Andes. Although Capsicum has been extensively studied and great advances have been made in the understanding of its taxonomy and the relationships amongst species, there is no monographic treatment of the genus as a whole. Based on morphological and molecular evidence studied from field and herbarium specimens, we present here a comprehensive taxonomic treatment for the genus, including updated information about morphology, anatomy, karyology, phylogeny and distribution. We recognise 43 species and five varieties, including C.mirum Barboza, sp. nov. from São Paulo State, Brazil and a new combination C.muticum (Sendtn.) Barboza, comb. nov.; five of these taxa are cultivated worldwide (C.annuumL.var.annuum, C.baccatumL.var.pendulum (Willd.) Eshbaugh, C.baccatumL.var.umbilicatum (Vell.) Hunz. & Barboza, C.chinense Jacq. and C.frutescens L.). Nomenclatural revision of the 265 names attributed to chili peppers resulted in 89 new lectotypifications and five new neotypifications. Identification keys and detailed descriptions, maps and illustrations for all taxa are provided.

Taxonomic revision of Saxicolella (Podostemaceae), African waterfall plants highly threatened by Hydro-Electric projects

SummarySpecies of the genus Saxicolella Engl. (Podostemaceae) are African rheophytes, restricted to rapids and waterfalls as are all members of the family. Previously, Saxicolella sensu lato was shown to be polyphyletic with two separate clades. The name Pohliella Engl. was recently resurrected for one clade that is sister to the American genera Ceratolacis (Tul.) Wedd., Podostemum Michx. and all Old World Podostemoideae. Pohliella has distichous phyllotaxy, bilocular ovaries, filiform roots with paired holdfasts, and rootcaps. The second clade, Saxicolella sensu stricto, including the type of the generic name, has spiral phyllotaxy, unilocular ovaries, ribbon-like or crustose roots that lack both holdfasts and rootcaps. Saxicolella sensu stricto, sampled from the type species, S. nana Engl. of Cameroon, is embedded within and near the base of the major clade of African podostemoids and is sister to all other African genera apart from Inversodicraea R.E.Fr. and Monandriella Engl. Recently reduced to three species in Cameroon and SE Nigeria by the resurrection of Pohliella, Saxicolella sensu stricto is expanded to eight species in this monograph by description of five new taxa. Saxicolella futa Cheek and S. deniseae Cheek are newly described from Guinea, S. ijim Cheek from Cameroon, the informally named S. sp. A from Gabon, and S. angola Cheek from Angola. The known geographic range of the genus is thus expanded c. 2,500 km westwards to Guinea from eastern Nigeria and c.1,500 km southeastwards from near Yaoundé to Cuanza do Sul, Angola. The greatest concentration of species occurs in the Cross-Sanaga interval of western Cameroon and eastern Nigeria, with three species. Cameroon (3 species) followed by Nigeria and Guinea (2 species each) are the countries with highest species diversity. A classification is proposed grouping the species into three subgenera (Saxicolella, Butumia (G.Taylor) Cheek comb. et stat. nov. and Kinkonia Cheek subgen. nov.) based on root morphology and shoot position and morphology. The discovery, morphology, circumscription, distribution and ecology of Saxicolella is reviewed, an identification key to the species is presented, together with descriptions, synonymy and links to illustrations. All of the species are provisionally assessed as either Endangered or Critically Endangered using the IUCN 2012 Red List Criteria. The major threats, above all, are hydro-electric projects. Saxicolella deniseae may already be globally extinct, and two of the four known locations of S. angola appear lost, S. sp. A of Gabon is threatened at at least one of its three locations, while S. futa is threatened at all three locations. Contamination of watercourses by increased turbidity from silt-load due to anthropic changes and by eutrophication from pollution are also threats for the majority of the species.

Revision of the North American Genus Bistanta Anderson, 2018

Revision of the North American Genus Bistanta Anderson, 2018

Taxonomy and phylogenetic analysis of the South American genus

The systematics of Philodromidae is far from complete, especially for the Neotropical genera. Among these, Petrichus Simon, 1886 is a poorly known genus restricted to arid and semi-arid environments of South America. In this work, we performed a total-evidence analysis to assess the phylogenetic relationships of Petrichus and revised the taxonomy. Petrichus is monophyletic and closer to Titanebo and the New World Ebo. Within Petrichus, two clades are obtained: the Eremean Clade, containing five species displaying a Neotropical distribution; and the Patagonian Clade, with the seven species inhabiting southern South America. Our results also support a previous hypothesis on the phylogenetic relationships within Philodromidae. Thanatini is monophyletic and includes Fageia and Berlandiella, although this is not statistically supported, whereas Philodromini emerges as paraphyletic. We propose Philodromini be expanded to contain all genera having eyes on tubercles analysed in this work plus the closely related Halodromus, whereas the circumscription of Thanatini should await future phylogenetic analyses with new evidence. As for taxonomic proposals, we synonymise Bacillocnemis Mello-Leitão, 1938 with Petrichus, Petrichus ornatus Schiapelli & Gerschman, 1942 and P. luteus (Nicolet, 1849) with P. junior (Nicolet, 1849), P. lancearius Simon, 1905 with P. tullgreni Simon, 1902; we transfer P. corticinus Mello-Leitão, 1944 to Misumenoides Pickard-Cambridge, 1900 (Thomisidae); and P. fuliginosus (Nicolet, 1849), P. cinereus Tullgren, 1901, P. sordidus Tullgren, 1901 and P. zonatus Tullgren, 1901 are regarded as nomina dubia. In total, 13 species are recognised for the genus, of which four are new (described by Griotti & Grismado): P. spira, from western Argentina, P. patagoniensis, from south-western Argentina, P. roigjunenti, from Argentina and Chile and P. eremicus, from north-central Chile. ZooBank: http://zoobank.org/References/1220255e-6431-45c2-adfe-ed58d1f89b17

A Taxonomic Revision of the Central American Genus Mesoamerantha (Bromeliaceae: Hechtioideae)

A taxonomic revision of the Central American genus Mesoamerantha I. Ramírez & K. Romero is here presented. Each species entry includes full nomenclature, a morphological description, distributional and phenological data, a discussion of affinities, illustrations, and a conservation assessment following IUCN guidelines. In addition, epitypes are proposed for M. dichroantha (Donn. Sm.) I. Ramírez & K. Romero, a species endemic to Guatemala, and for M. malvernii (Gilmartin) I. Ramírez & K. Romero, a species restricted to Honduras and Nicaragua, the holotypes of which represent a single sex and are not sufficient for unambiguous identification. An artificial key is also included in order to identify live as well as herbarium specimens of all taxa.

Testing the Taxonomy of Amphidorini Leconte (Coleoptera: Tenebrionidae): A Molecular Phylogeny Leveraging Museum Sequencing

The tribe Amphidorini LeConte, 1862, commonly known as the Desert Stink Beetles, is a species-rich group of flightless darkling beetles in the subfamily Blaptinae Leach, 1815 distributed throughout the Western Hemisphere and contains 252 valid species-group taxa within seven genera. In this study we provide molecular phylogenetic analyses based on seven loci to assess both the tribal monophyly and composition of Amphidorini as well as the genus and species-group relationships within the tribe. We find strong support for the exclusion of the South American genus Nycterinus Eschscholtz, 1829 from the rest of the otherwise North American tribe. Nycterinus is recovered in a distantly related clade comprising several Western Hemisphere tribes of Tenebrioninae Latrielle, 1802 and is placed as incertae sedis within that subfamily. Within the remaining 23 genera and subgenera within Amphidorini, 11 were recovered as distinct lineages. The composition and relationships of genera and subgenera of the large genus Eleodes Eschscholtz, 1829 are discussed along with the need for an overhaul in genus-group classification which will likely require the elevation to genus of many current constituent lineages of Eleodes.

Systematic Revision of the Genus Hipalmus Bates, 1870 With Comments on the Placement of Psammetichus dissimilis Peña, 1994 and Zophobas lugubris Boheman, 1858 (Coleoptera: Tenebrionidae: Tenebrioninae)

The South American genus Hipalmus Bates, 1870 (Tenebrioninae: Tenebrionini), distributed in the Pacific coast of Peru and Ecuador, is revised using external morphology and including for the first time details on sexual dimorphism, defensive glands, and male and female genitalia. The genus and its species are redescribed. New distribution records, photographs of the two included species, illustrations of genital features, and distribution maps are provided. A discussion including differences in character states between Hipalmus and Zophobas Dejean, 1834 as well as the tribal placement of Hipalmus in Tenebrionini on the basis of external and internal morphology is also included. The following nomenclatural changes are proposed: Zophobas lugubris Boheman, 1858 is transferred to Hipalmus, Psammetichus dissimilis Peña, 1994 is synonymized under Hipalmus costatus (Guérin-Méneville, 1831) and Hipalmus aequatorius Kolbe, 1901 is synonymized under Hipalmus lugubris (Boheman, 1858) comb. nov.

The genus Symmela Erichson, 1835 (Coleoptera, Scarabaeidae, Sericini): taxonomy and phylogenetic analysis

ABSTRACT The taxonomy of the species of the South American genus Symmela Erichson, 1835 is revised. As a result, we propose the following new synonymies: Symmela longula Erichson, 1835 (= Symmela angustula Moser 1919 syn. nov.), Symmela nitida Erichson, 1835 (= Symmela tenella Erichson, 1835 syn. nov.). Fourteen new species are described: Symmela beskei sp. nov., S. capixaba sp. nov., S. clarki sp. nov., S. erichsoni sp. nov., S. fuhrmanni sp. nov., S. guerlini sp. nov., S. iannuzziae sp. nov., S. martinezi sp. nov., S. nunesorum sp. nov., S. paschoali sp. nov., S. pseudopaca sp. nov., S. reischei sp. nov., S. terezae sp. nov., S. unidentata sp. nov. The lectotypes of the following taxa were designated: Serica flavimana Gory, 1832, Symmela angustula Moser, 1919, S. clypeata Erichson, 1835, S. corumbana Moser, 1921, S. instabilis Erichson, 1835, S. longula Erichson, 1835, S. mutabilis Erichson, 1835, S. nitidicollis Burmeister, 1855, S. opaca Erichson, 1835, S. tarsalis Moser, 1919, and S. tenella Erichson, 1835. Species are redescribed and a key to the species is given; details of external morphological features as well as the aedeagus are illustrated for all taxa. Distribution of the species is shown on a map. A phylogenetic analysis based on 137 morphological characters and parsimony indicates that Symmela is monophyletic. http://www.zoobank.org/urn:lsid:zoobank.org:pub:5147CC1B-6144-4CA4-BA63-E39ED0A20E1C

Pisonia calafia (Nyctaginaceae) especie nueva de la Península de Baja California, México

El género Pisonia es primordialmente americano, se distribuye principalmente en regiones subtropicales y tropicales. En este trabajo se describe y documenta la nueva especie Pisonia calafia. Este taxon consiste de una relativamente pequeña población en la costa de la región de Los Cabos en la península de Baja California. La principal característica que diferencia a P. calafia del resto de las especies de este género es la carencia de sulcos y glándulas en el fruto. En adición a la descripción morfológica, se documenta la afinidad evolutiva del nuevo taxon con base en el análisis filogenético de la secuencia de nrITS. Las poblaciones conocidas consisten de unas pocas docenas de individuos, seriamente amenazados por el desarrollo de proyectos turísticos en la zona.

Systematic revision and phylogeny of Paragripopteryx Enderlein, 1909 (Plecoptera: Gripopterygidae).

Among the Neotropical gripopterygids, the genus Paragripopteryx occurs along the Brazilian Atlantic coast to Uruguay. Since its first recognition by Enderlein in 1909, the genus underwent a confusing taxonomic history with some combinations. In this study, we aim to revise Paragripopteryx and present the first morphology-based phylogeny for the genus. The analysis comprised 38 morphological characters and their respective states in 30 terminal taxa, including 13 Paragripopteryx species, two new species identified as belonging to Paragripopteryx, and 15 outgroup species, among which we can highlight 12 different South American genera and one Australian genus of Gripopterygidae. The cladistic analysis yielded a parsimonious tree for k = 3 (137 steps, consistency index = 0.445, and retention index = 0.591) where most Paragripopteryx are nested, except for Uruguayan Paragripopteryx munoai. We can then infer that in its current circumscription Paragripopteryx is polyphyletic. The following two species are described: Paragripopteryx dasalmas sp. nov. and Paragripopteryx ogum sp. nov. Paragripopteryx baratinii is designated as a nomen dubium. Additionally, we provide a key for species identification, updated geographical records, and illustrations for all species. As a corollary, our study gathers relevant morphological information that can help to better understand this genus and create foundations for the next steps.

The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus

The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus

The genus Raysymmela Saylor, 1947 (Coleoptera, Scarabaeidae, Melolonthinae, Sericini): taxonomy and phylogenetic analysis

Abstract Here we revise the taxonomy of the South American genus Raysymmela Saylor, 1947 and perform a phylogenetic analysis based on 126 morphological characters. We propose one new synonym, Raysymmela pallipes (Blanchard, 1850) (= Symmela boliviensis Moser, 1919 syn. n.), and three new combinations, Raysymmela costaricensis (Moser, 1924) comb. n., Raysymmela seticollis (Moser, 1921) comb. n., and Raysymmela varians (Erichson, 1847) comb. n. Two new species are described: Raysymmela equatorialis sp. n. (Ecuador) and R. erwini sp. n. (Bolivia). Lectotypes of following taxa were designated: Symmela boliviensis Moser, 1919, S. bruchi Moser, 1924, S. costaricensis Moser, 1924, S. curtula Erichson, 1835, S. pallipes Blanchard, 1850, S. seticollis Moser, 1921, and S. varians Erichson, 1847. Species are redescribed and a key to species is given, external morphological features as well as aedeagus are illustrated for all taxa. Distribution maps as well as a key to currently known South American genera of Sericini are provided. From phylogenetic analysis using parsimony, Raysymmela is not recovered as monophyletic.

New Distributional Records of Phidippus (Araneae: Salticidae) for Baja California and Mexico: An Integrative Approach

Because of its heterogeneity in ecoregions and its varied topography, the Mexican peninsula of Baja California (BCP) is an area of high diversity for many taxa, including spiders. However, a paucity of studies means that the diversity of BCP’s spiders is generally poorly known. The North American jumping spider genus Phidippus comprises over 60 species, of which approximately 45% are found in Mexico. Among those, 6 have been recorded to date from the BCP but adding up the species recorded in nearby states, up to 20 more can be expected. As part of a larger study on the evolution and biogeography of the North American genus Phidippus, the aim here was to explore the diversity of the genus in the BCP using an integrative taxonomic approach and to present new distributional records. Until now, at least ten species have been collected from the BCP, one of which is a new record for Mexico, three new records for the BCP, and at least one undescribed species.

Phylogeny of the South American genus

The genus Baripus Dejean is a carabid beetle endemic to southern South America, inhabiting grassland and shrub habitats in mountain and lowland areas. In this work, the phylogeny of the genus is updated and new species restricted to isolated mountains from the Patagonia Biogeographic Province are described. The cladistic analysis showed that the new mountain species comprise a monophyletic clade with five other species. Within this group, the species are arranged in two internal clades. Each clade contains one or two lowland species with a wide distribution range and the remaining species with microendemic distribution on each mountain system. Their distribution pattern suggests that mountain species of Baripus could have originated since (by) the end of the Cenozoic when the mountains uplifted and acted as a refuge for populations of lowland species that remained isolated and later became differentiated from one another. Based on morphological and cytochrome c oxidase subunit I molecular data, Baripus (Cardiophthalmus) palauco, sp. nov., Baripus (Cardiophthalmus) tromen, sp. nov., Baripus (Cardiophthalmus) aucamahuida, sp. nov. and Baripus (Cardiophthalmus) payun, sp. nov. are described and a key to all currently known species of Baripus (Cardiophthalmus) is provided.