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Supplemental Material for 'Convergent evolution of a eusuchian-type secondary palate within Shartegosuchidae. (American Museum novitates, no. 3901)'
No full textSupplemental Material for 'Convergent evolution of a eusuchian-type secondary palate within Shartegosuchidae. (American Museum novitates, no. 3901)
Two species of Diadumene (Cnidaria, Actiniaria).
Get PDF45 pages : illustrations (some color), color map ; 26 cm.Diadumenidae is a monogeneric family comprised of 10 valid species in the genus Diadumene. Although these species are distributed in all but the Southern Ocean, Diadumene lineata is a cosmopolitan species and one of the most widely distributed marine organisms. Recent phylogenetic analyses with multiple species have recovered Diadumenidae as a monophyletic group with high support. Although generic placement is straightforward, species-level identifications within Diadumene are difficult because species are defined by a mosaic of characters that vary in degree rather than kind. Two species of the genus have been recorded in the southwestern Atlantic: D. paranaensis along the south coast of Brazil and D. lineata along the southeast and northeast coasts of Brazil as well as in Argentina. Here we record D. leucolena for the first time in the southern hemisphere and describe D. manezinha, sp. nov., raising to four the number of species of Diadumene for Brazil and to 11 worldwide. We incorporated microcomputed tomography (micro-CT) into the description of both species in the first application of the method for Actiniaria. We evaluate the utility of micro-CT imaging and its potential to generate fast, low-cost, and high-resolution datasets despite the anemone's low-density soft tissue. We present a protocol for sample handling, chemical staining, and scanning parameters that resulted in satisfactory imaging of the two specimens examined. We also analyze advantages and limitations of using micro-CT over traditional techniques in the study of sea anemones
Systematics of small-bodied Neacomys.
Get PDF38 pages : illustrations (some color), color map ; 26 cm.The genus Neacomys includes 10 recognized species of Neotropical spiny mice in the tribe Oryzomyini. Five species have previously been reported from Peru, but the small-bodied Peruvian taxa remain unrevised. In this report, we present the first systematic and taxonomic revision of small-bodied Neacomys populations in Peru and describe two new species based on molecular, morphological, and karyotype data: (1) Neacomys rosalindae, sp. nov., from northeastern Peru, is distinguished from congeneric species by, among other differences, short incisive foramina with a wide maxillary portion of the septum, a small subsquamosal fenestra, and a karyotype of 2n = 48, FN = 50. (2) Neacomys macedoruizi, sp. nov., from central Peru, is distinguished by its gray-based ventral fur, large infraorbital foramen, and karyotype of 2n = 28, FN = 36, with a distinctively large pair of metacentric chromosomes. The results of our molecular analyses suggest that N. minutus (as currently recognized) is a species complex comprised of N. minutus sensu stricto, N. macedoruizi, and a third form that remains to be described. The other species described here, N. rosalindae, is the sister taxon to a cluster that includes the N. minutus complex plus N. musseri. Our data suggest that the upper Amazon River constitutes an important dispersal barrier for species in this genus
Feeding vs Falling. The growth and collapse of molecular clouds in a turbulent interstellar medium
No full textIn order to understand the origin of observed molecular cloud properties, it is critical to understand how clouds interact with their environments during their formation, growth and collapse. It has been suggested that accretion-driven turbulence can maintain clouds in a highly turbulent state, prevent- ing runaway collapse, and explaining the observed non-thermal velocity dispersions. We present 3D, adaptive-mesh-refinement (AMR), magnetohydrodynamics (MHD) simulations of a kiloparsec-scale, stratified, supernova-driven, self-gravitating, interstellar medium, including diffuse heating and radia- tive cooling. These simulations model the formation and evolution of a molecular cloud population in the turbulent interstellar medium. We use zoom-in techniques to focus on the dynamics of the mass accretion and its history for individual molecular clouds. We find that mass accretion onto molecular clouds proceeds as a combination of turbulent flow and near free-fall accretion of a gravitationally bound envelope. Nearby supernova explosions have a dual role, compressing the envelope, increasing mass accretion rates, but also disrupting parts of the envelope and eroding mass from the cloud’s surface. It appears that the inflow rate of kinetic energy onto clouds from supernova explosions is in- sufficient to explain the net rate of change of the cloud kinetic energy. In the absence of self-consistent star formation, conversion of gravitational potential into kinetic energy during contraction seems to be the main driver of non-thermal motions within clouds. We conclude that although clouds interact strongly with their environments, bound clouds are always in a state of gravitational contraction, close to runaway, and their properties are a natural result of this collapse
Molecular phylogenetics of the wrens and allies (Passeriformes, Certhioidea), with comments on the relationships of Ferminia. (American Museum novitates, no. 3887)
No full text27 pages : illustrations ; 26 cm.The superfamily Certhioidea is distributed on four continents and while comprising relatively few species, includes forms as diverse as creepers, nuthatches, gnatcatchers, and wrens. Previous attempts to infer the phylogeny of this lineage have focused on its higher-level relationships, consequently undersampling the New World wrens. This study reports the first nearly genus-level sampling of certhioids, based on concatenated and species tree analyses of 8520 bases of DNA sequence data from six gene regions. These analyses, while failing to completely resolve basal certhioid relationships, corroborate the monophyly of a diverse New World clade of gnatcatchers, gnatwrens, and wrens, and significantly improve our understanding of wren relationships. The inferred relationships among certhioids and wrens support an Old World origin for these lineages, with dispersal of the New World clade in the mid-Miocene, suggesting expansion and early diversification of the lineage through North America. This scenario suggests a minimum of six independent dispersal events into South America in this lineage, at least some likely to have been made prior to the Pliocene
New species of Hsunycteris.
No full text26 pages : illustrations (some color), map ; 26 cm.A new species of the nectarivorous bat genus Hsunycteris is described from lowland Amazonian forest in northeastern Peru. The new species, H. dashe, can be distinguished from other congeners by its larger size; V-shaped array of dermal chin papillae separated by a wide basal cleft; metacarpal V longer than metacarpal IV; broad rostrum; lateral margin of infraorbital foramen not projecting beyond rostral outline in dorsal view; well-developed sphenoidal crest; large outer upper incisors; weakly developed lingual cusp on P5; and well-developed, labially oriented M1 parastyle. A phylogenetic analysis of cytochrome-b sequence data indicates that H. dashe is sister to a clade that includes all other species of the genus including H. cadenai, H. pattoni, and a paraphyletic H. thomasi. We provide a key based on craniodental and external characters of all four known species of Hsunycteris
Spider genus Orchestina in the Americas.
No full text362 pages : illustrations (some color), maps ; 26 cm.The genus Orchestina Simon is distributed worldwide and is characterized by having an enlarged fourth femur with which these species are capable of jumping. The genus is also characterized by having a well-sclerotized sperm duct, a near H-shaped arrangement of the eye group, a 4-4-3-3 pattern of raised receptors on the tarsal organs of the legs I-IV, respectively, and by lacking spines on all the legs. All these characters, together with molecular evidence, support the monophyly of the genus, as well as its placement as sister group of Oonopinae. Most American species of Orchestina inhabit the forest foliage and canopy, but in unforested areas they also occur in shrubs and grasses. In this work, we revise the American representatives of Orchestina in a comprehensive context for the first time. In the past, six species were known from the Americas: five from the United States and only one from South America, described from Venezuela. After the study of the principal collections of the world and several field trips to several South American countries, we describe 85 new species and redescribe all previously known species. Matching sexes was occasionally problematic; while females are very homogeneous in somatic traits, males may have modifications on different parts of the body, making the matching very difficult. Therefore, in this review 56 of the species are described from only one sex, whereas 20 unmatched species are informally described as morphospecies, pending the discovery of conspecific sexes. Two species, O. pavesiiformis Saaristo and O. dentifera Simon, originally known from Israel and Sri Lanka, respectively, are here reported as introduced in several countries in the Americas and other continents. O. justini Saaristo described from the Seychelles is here considered a synonym of O. dentifera. One species, O. truncata Wunderlich, previously known as a subfossil spider from Colombian copal is here tentatively redescribed based on recent material from Costa Rica, Colombia, and Ecuador; the female is also described for the first time. The species list by country is as follows (numbers refer to records, independently of the locality of the type material): United States (9 species: O. utahana Chamberlin and Ivie, O. moaba Chamberlin and Ivie, O. obscura Chamberlin and Ivie, O. saltitans Banks, O. nadleri Chickering, the introduced O. pavesiiformis Saaristo, and three new species, O. quasimodo, O. kamehameha, and O. auburndalensis); Mexico (3 species: O. utahana Chamberlin and Ivie, and two new species, O. nahuatl and O. chaparrita); Guatemala (1 new species: O. guatemala); Costa Rica (3 new species: O. laselva, O. griswoldi, and O. chiriqui; and the previously known O. truncata Wunderlich); Panama (5 new species: O. chiriqui, O. labarquei, O. pan, O. campana, and O. galapagos); Jamaica (2 species, the introduced O. dentifera Simon and O. galapagos); Haiti and Dominican Republic (only the introduced O. dentifera Simon); Colombia (6 new species: O. filandia, O. zingara, O. arboleda, O. cali, O. platnicki, O. pakitza; and O. truncata Wunderlich, plus the morphospecies OMI020 and OMI038); Venezuela (7 species: O. saltabunda; and 6 new, O. venezuela, O. aragua, O. bolivar, O. maracay, O. ranchogrande, and O. neblina); Trinidad and Tobago (1 new species: O. kairi); Guyana (1 morphospecies: OMI026); Ecuador (18 new species: O. galapagos, O. fernandina, O. erwini, O. ecuatoriensis, O. sotoi, O. magna, O. shuar, O. golem, O. waorani, O. tzantza, O. predator, O. goblin, O. yanayacu, O. otonga, O. santodomingo, O. quijos, O. mayo, O. laselva, and O. truncata Wunderlich, plus the morphospecies OMI020, OMI021, OMI022, OMI023, OMI024, OMI025, OMI026, OMI027, OMI029, OMI036, and OMI038); Peru (9 new species: O. cajamarca, O. comaina, O. atocongo, O. mancocapac, O. silvae, O. madrededios, O. pakitza, O. losamigos, O. golem, and the morphospecies OMI020, OMI023, OMI026, and OMI030); Brazil (25 new species: O. cristinae, O. coari, O. moura, O. valquiria, O. aproeste, O. caxiuana, O. para, O. taruma, O. retiro, O. divisor, O. juruti, O. platnicki, O. iemanja, O. bonaldoi, O. rapaz, O. itapety, O. catarina, O. leon, O. saudade, O. sarava, O. goblin, O. sotoi, O. golem, O. waorani, O. ucumar, the introduced O. pavesiiformis Saaristo, and O. dentifera Simon, plus the morphospecies OMI021, OMI023, OMI024, OMI025, OMI026, OMI027, OMI029, OMI032, OMI033, OMI034, OMI035, OMI036, OMI037, OMI039, and OMI040); Bolivia (3 new species: O. moyuchi, O. grismadoi, and O. ucumar); Chile (12 new species: O. pandeazucar, O. caleta, O. totoralillo, O. pizarroi, O. molles, O. granizo, O. quenies, O. curico, O. cachai, O. nahuelbuta, O. jaiba, and O. osorno); and Argentina (6 new species: O. ucumar, O. andianavarroi, O. luispi, O. cristinae, O. platnicki, O. jaiba, and the introduced O. pavesiiformis Saaristo). Although the internal relationships of the genus are still not clear, we suggest some groups of species based on morphological characters and geographic distributions. Species from the western United States share the presence of a net-shaped pattern of coloration and, in some species, modifications of carapace or first legs of males. Females of this group are characterized by the presence of a thin, generally long and twisted anterior receptaculum and external pockets on the epigastric region. This group inhabits in a geographic region that remained isolated during the late Cretaceous and is still isolated by geographic and climatic conditions. Species groups in South American members were more difficult to establish, given their wide diversity. However, some species are unique in having internal pockets in female genitalia and apophyses on the male copulatory bulb. The Chilean species are probably a monophyletic group; they are separated from the rest by the combined presence of external pockets and ridges on the epigastric region of female, whereas males are very similar in the morphology of copulatory bulb, which is very simple, with long embolus and sometimes with additional spine-shaped apophysis. This group may have experienced events of isolation during and after the elevation of the Andes range. As in other members of the family the genus is interesting for the presence of secondary sexual characters in males whereas females are practically homogenous in somatic characters. However, female genital morphology is variable, which may suggest a coevolution with somatic characters in males and probably mechanical interactions. Although this work reveals the incredible diversity of this genus, many important geographic regions remain undersampled and records for some countries are entirely lacking
A new species of Monodelphis (Didelphimorphia, Didelphidae) from the Brazilian Amazon. (American Museum novitates, no. 3872)
No full text20 pages : illustrations (some color), map ; 26 cm.We describe a new species of the didelphid marsupial genus Monodelphis from Brazil, where it appears to be widely distributed in the states of Pará, Mato Grosso, Rondônia, and Acre. Monodelphis saci, new species, belongs to the subgenus Mygalodelphys, and analyses of DNA sequence data suggest that it is most closely related to M. handleyi, M. osgoodi, and M. peruviana. Diagnostic morphological traits include pelage coloration, qualitative aspects of craniodental morphology, and a distinctive range of morphometric variation. The new species has sometimes been misidentified in the literature as M. kunsi, a distinct but apparently allopatric taxon. Monodelphis saci occurs sympatrically with M. emiliae, M. glirina, and M. touan in the rainforested lowlands south of the Amazon River
Osteology of ceratomorph Hyrachyus modestus.
No full text68 pages : illustrations ; 26 cm.The middle Eocene ceratomorph Hyrachyus has been considered a pivotal genus in ceratomorph evolution, either as a transitional form from tapiroids to rhinocerotoids, giving rise to all later rhinocerotoids, or else as the sister taxon to other rhinocerotoids. Thus, Hyrachyus has been commonly chosen as an outgroup in phylogenetic analyses of rhinocerotoids. However, little has been published on the osteology of Hyrachyus, even though well-preserved craniodental and postcranial specimens of this taxon have been in collections for decades. Here, we describe and illustrate the cranial and postcranial osteology of Hyrachyus modestus, based mainly on the exceptionally preserved specimens housed at the American Museum of Natural History, specifically AMNH FM 12664. Our bone-by-bone description provides detailed information on the osteological morphology of Hyrachyus, which should be useful for phylogenetic analyses of both rhinocerotoids and perissodactyls in general, because it provides one of the more complete and best-preserved examples of the skeleton of an earlier Eocene perissodactyl...