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1.
The mouse opossums of the genus Thylamys constitute a group of species mainly adapted to open xeric‐like habitats and restricted to the southern portion of South America. We used molecular data (mitochondrial and nuclear sequences) to evaluate the phylogenetic and biogeographical relationships of all currently known living species of the genus, recognizing a new taxon from the middle and high elevations of the Peruvian Andes and evaluating the phylogenetic structuring within T. pallidior and T. elegans, as well as the validity of T. sponsorius, T. cinderella and T. tatei, and the haplogroups recognized within T. pusillus. Our results confirm the monophyly of the genus and that the Caatinga and the Cerrado inhabitants Thylamys karimii and T. velutinus are the most basal species in the radiation of Thylamys. We also calibrated a molecular clock which hypothesized a time of origin of the genus of about 24 My, with most species differentiating in middle and late Miocene and Plio‐Pleistocene times of South America.  相似文献   

2.
Rhagovelia pediformis sp. n. is described from western Colombia and placed in the R. elegans group.  相似文献   

3.
Nucleotide sequence data from the mitochondrial cytochrome b gene were used to evaluate the phylogenetic relationships among mouse opossum species of the genus Thylamys. Based on approximately 1000 bp in five of the six species of the genus and including different localities for some of the species, we concluded that T. macrura from the subtropical forests of eastern Paraguay is the most primitive taxon. Subsequent radiation of the genus is explained mainly via founder effect speciation. This evolutionary scenario would account for the speciation of T. pusilla, T. venusta, T. pallidior, and T. elegans in the Chaco, southern Bolivia and northern Argentina, the Andean Altiplano, the Coastal Desert of Chile, and coastal Perú, respectively. Calibration of a molecular clock set the Pleistocene as the period for the differentiation of Thylamys species. The molecular results confirm the strong genetic connection between populations that inhabit the "pre-cordillera" of northern Chile (T. pallidior) and the canyons that run through the Atacama Desert to the lowlands in northern Chile. Our results confirm the occurrence of two Thylamys species in Chile, T. pallidior and T. elegans, within and south to the Atacama Desert, respectively.  相似文献   

4.
From August 2011 to November 2013, 68 opossums (8 Didelphis sp., 40 Didelphis virginiana, 15 Didelphis marsupialis, and 5 Philander opossum) were collected in 18 localities from 12 Mexican states. A total of 12,188 helminths representing 21 taxa were identified (6 trematodes, 2 cestodes, 3 acanthocephalans and 10 nematodes). Sixty-six new locality records, 9 new host records, and one species, the trematode Brachylaima didelphus, is added to the composition of the helminth fauna of the opossums in Mexico. These data, in conjunction with previous records, bring the number of taxa parasitizing the Mexican terrestrial marsupials to 41. Among these species, we recognized a group of helminths typical of didelphids in other parts of the Americas. This group is constituted by the trematode Rhopalias coronatus, the acanthocephalan Oligacanthorhynchus microcephalus and the nematodes Cruzia tentaculata, Gnathostoma turgidum, and Turgida turgida. In general, the helminth fauna of each didelphid species showed a stable taxonomic composition with respect to previously sampled sites. This situation suggests that the rate of accumulation of helminth species in the inventory of these 3 species of terrestrial marsupials in the Neotropical portion of Mexico is decreasing; however, new samplings in the Nearctic portion of this country will probably increase the richness of the helminthological inventory of this group of mammals.  相似文献   

5.
Carlos Parra-O 《Brittonia》2000,52(4):320-324
Morella chevalieri is described as new and is illustrated; it grows in the Andes in northern Argentina and southern and central Bolivia. A key that differentiates this new species from the monoeciousMyrica pubescens is presented. The dioecious Morella chevalieri is characterized by the following: leaf blade elliptic to narrowly elliptic, margin serrate (at least in the distal 2/3); staminate flowers with one or no secondary bracts (if present, linear or band-shaped) and secondary bracts in the pistillate flower 2–3 (seldom 4).
Resumen  Se describe e ilustra aMorella chevalieri como nueva especie; se distribuye en los Andes de la parte norte de Argentina y de las partes sur y central de Bolivia. Se presenta una clave que diferencia a esta nueva especie de la monóicaMyrica pubescens. La dióica Morella chevalieri se reconoce por los siguientes caracteres: lámina de la hoja elíptica o angostamente elíptica, margen aserrada (al menos en las dos terceras partes distales); flores estaminadas sin o con una bráctea secundaria (esta con forma linear o acintada) y brácteas secundarias de la flores pistiladas de 2 a 3 (raramente 4).
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6.
The subgenus Marmosa (Micoureus) Lesson, 1842 includes six species of long-tailed, black masked mouse-opossums widely distributed in forested areas of the Neotropics from northern Argentina to Belize. Most of the nominal forms of Marmosa (Micoureus) have not been revised since 1933 and some currently accepted synonymies are in need of revision; similarly distributions of these forms remain for the most part unclear. Herein, we report Paraguayan new and noteworthy locality records for Marmosa (Micoureus), including the first records for the western Dry Chaco region. Specimens were identified to the species level on the basis of morphological and molecular data. In addition, we conducted a phylogenetic analysis that includes sequences of five of the six species currently recognized of Micoureus incorporating a total of 70 sequences of the subgenus. This constitute the most taxonomically and geographically dense phylogenetic analysis of Micoureus. Results show that the most basal dichotomy of the Micoureus clade does not delimit cis- and trans-Andean reciprocally monophyletic groups, rending the cis group paraphyletic to the single trans-species included, suggesting that the colonization of the western (trans) side of the Andes was a relatively late event in the biogeographic history of Micoureus. In addition, the phylogenetic analysis shows that additional taxonomic work is much needed to clarify the number of distinct biological units, either species or subspecies, within Micoureus.  相似文献   

7.
One species of digenean, Zeylanurotrema sphenomorphi n. sp., and 2 nematode species, Meteterakis crombiei n. sp. and Physalopteroides milnensis n. sp., from the intestine of Sphenomorphus jobiensis, are described and illustrated. Zeylanurotrema sphenomorphi n. sp. represents the second species, Meteterakis crombiei n. sp. the 18th species, and Physalopteroides milnensis n. sp. the 19th species assigned to each respective genus. In addition, 1 species of cestode, Oochoristica javaensis; 7 nematode species, Abbreviata oligopapillata, Aplectana macintoshii, Aplectana zweifli, Cosmocerca zugi, Maxvachonia adamsoni, Oswaldocruzia bakeri, Parapharyngodon maplestonei; 1 species of acanthocephalan, Acanthocephalus bufonis; and 1 species of pentastome, Kiricephalus sp., were found. With the exception of Abbreviata oligopapillata, Sphenomorphus jobiensis represents a new host record for each species of endoparasite.  相似文献   

8.
Material from southern Bolivia, recently collected by Stephan Beck, is described as a new genus and species, Stephanbeckia plumosa (Compositae: Liabeae). Both morphological and molecular data place the genus in the broadly interpreted subtribe Paranepheliinae, but clearly distinct from other members. It differs morphologically by its small size, deciduous plumose pappus, lack of paleae, and compressed bicostate achenes. A key to the genera of the Liabeae is provided.  相似文献   

9.
10.
A Oliva 《ZooKeys》2012,(203):1-14
A new species of the forensically interesting genus Oxelytrum Gistel (Coleoptera, Silphidae), Oxelytrum selknan, is described from Santa Cruz and Tierra del Fuego provinces, Argentina. The new species resembles Oxelytrum biguttatum (Philippi) in outer aspect, but has different male genitalia, in particular a median lobe longer than the paramera. All the described species of Oxelytrum have the median lobe shorter than the paramera. The internal sac, as far as it could be reconstructed from dry-pinned specimens, also shows differences between the two species. A key to the species of Oxelytrum is given and illustrated.  相似文献   

11.
12.
Sphyraena iburiensis sp. nov. is described, and taxonomic reviews are provided for S. obtusata and S. pinguis. These species, characterized by having 2 gill rakers, are defined as the S. obtusata group. Sphyraena iburiensis, known only from the Pacific coast of southern Japan, is characterized by 8.5–9.5 scales above the lateral line, a single row of scales in the groove along the lower margin of the suborbital region from the posterior tip of the maxilla to below the eye (=suborbital groove) not covered with skin, 2 distinct longitudinal stripes on the lateral surface of the body when fresh (upper stripe usually lost in preserved specimens), the lower stripe reaching the caudal-fin base just below the lateral line. Sphyraena obtusata, distributed in the Indo-West Pacific, is characterized by 5–7.5 scales above the lateral line, a single row of scales in the suborbital groove covered with skin, 2 somewhat indistinct longitudinal stripes on the lateral surface of the body when fresh (upper stripe usually lost in preserved specimens), the lower stripe joining the lateral line midway between the end of the second dorsal-fin base and caudal peduncle and extending to the middle of the caudal-fin base. Sphyraena pinguis, distributed in the Indo-West Pacific, is characterized by 7.5–9.5 scales above the lateral line, a single row of scales in the suborbital groove not covered with skin, and a single longitudinal stripe on the lateral surface of the body joining the lateral line slightly before or just below the end of the second dorsal-fin base and extending to the middle of the caudal-fin base. Seven (S. aureoflammea, S. brachygnathos, S. flavicauda, S. grandisquamis, S. langsar, S. lineata, and S. strenua) and 2 (S. chrysotaenia and S. schlegelii) nominal species are regarded as junior synonyms of S. obtusata and S. pinguis, respectively. In addition, lectotypes are designated for S. flavicauda, S. langsar, S. lineata, and S. obtusata. A key to the three species of the S. obtusata group is provided.  相似文献   

13.
14.
15.
No species of the genus Diacyclops has been so far cited from continental Argentina. Specimens collected from a roadside pool in the province of Catamarca on a plateau at 3700 m a.s.l. turned out to belong to a new species, Diacyclops andinus, which is described and illustrated in detail for both sexes. Main diagnostic features are: spine formula of swimming legs 3, 4, 4, 4; terminal spines of the distal endopod segment of leg 4 subequal; smooth furcal rami. The new species is a member of the D. bicuspidatus group, and is probably near the base of this line.  相似文献   

16.
The Trichostrongylina parasitic in the leaf-eared mouse Phyllotis sp. (Sigmodontinae) from the Province of Catamarca, Argentina are studied. Three new species of Stilestrongylus Freitas, Lent and Almeida, 1937 (Heligmosomoidea: Heligmonellidae: Nippostrongylinae) are described. Stilestrongylus andalgala n. sp. is distinguished from the most closely related species S. moreli Diaw, 1976 parasitic in Auliscomys boliviensis from Bolivia, by the absence of a common trunk of right rays 2 and 3, by left ray 4 shorter than ray 5, and by the shape of the female tail, without a mucron. Stilestrongylus catamarca n. sp. is distinguished from all the other species in the genus by hypertrophied rays 2, larger than rays 3, and from the closely related species Stilestrongylus barusi Durette-Desset, 1971, parasitic in Sigmodontomys alfari from Colombia, by right ray 4 longer than ray 5 and left ray 4 shorter than ray 5, by a larger spicule length/body length ratio (22.6% vs. 7.2%), and by the presence of a mucron on the female tail. Stilestrongylus gracielae n. sp. most closely resembles Stilestrongylus azarai Durette-Desset and Sutton, 1985, parasitic in Akodon azarae and in Graomys griseoflavus, and Stilestrongylus franciscanus Digiani and Durette-Desset, 2003, also parasitic in G. griseoflavus, both from Argentina. These latter differ from the new species by the right lobe of the caudal bursa: in S. azarai rays 4, 5 and 6 arise at same level from their common trunk and in S. franciscanus right rays 4 and 5 diverge at their distal extremity. Lamanema chavezi Becklund, 1963 (Molineoidea: Molineinae), a parasite of South American camelids, is reported in rodents for the second time.  相似文献   

17.
Asplenium basiscopicum is described, illustrated, and compared to the most similar species,A. purpurascens.  相似文献   

18.
We describe and illustrate 19 new species ofElaphoglossum from Bolivia:E. ayopayaense, E. carrascoense, E. choquetangae, E. cotapatense, E. crispipalea, E. cruzense, E. elkeae, E. ellenbergianum, E. gonzalesiae, E. inquisitivum, E. madidiense, E. murinum, E. neei, E. palmarum, E. pannosum, E. paucinervium, E. puberulentum, E. pulchrum, andE. sunduei.  相似文献   

19.
Yang D  Zhu Y 《ZooKeys》2011,(159):11-18
Sinosciapus liuaesp. n. is newly described from Taiwan. The genus Sinosciapus is discussed and a key to the three known Oriental species is provided.  相似文献   

20.
We analyzed new occurrences of Azygograptus lapworthi from the Cordillera Oriental, Argentina. The bearer sandstones levels, corresponding to the Acoite Formation, are overlying the deposits, in which the Didymograptellus bifidus Biozone (Lower Ordovician, upper Floian, Fl3) was previously recognized, and are overlain by younger pelitic levels yielding Xiphograptus lofuensis (Middle Ordovician, early Dapingian, Dp2). Previous records from the Central Andean Basin are also reviewed in detail and accurately correlated, allowing us to conclude that the Azygograptus lapworthi Biozone corresponds to the Middle Ordovician (lower Dapingian, Dp1). This biostratigraphic framework documents that the transition between the Lower and Middle Ordovician deposits occurs in the uppermost levels of the Acoite Formation in the Argentine Cordillera Oriental. It is additionally integrated with up to date conodont records to establish a high-resolution regional correlation, with equivalent deposits from the Puna of northwestern Argentina and Cordillera Oriental of Bolivia, and to discuss new insights for global correlation.  相似文献   

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