A new species of the didelphid marsupial genus Marmosops is described from the Pakaraima Highlands of western Guyana and from two highland sites in eastern Venezuela. All known specimens were collected on sandstone table mountains (eroded fragments of the Roraima Formation) in the eastern subregion of Pantepui. The new species, M. pakaraimae, is one of only seven mammals known to be endemic to Pantepui, and phylogenetic analyses of cytochrome-b sequence data indicate that its sister taxon is M. parvidens, a geographically adjacent lowland species. Our results, together with those from phylogenetic studies of other Pantepui endemic mammals, suggest that at least some of these highland taxa evolved from lowland species in the late Cenozoic and are neither ancient relicts of tepui vicariance nor the descendents of long-distance-dispersing Andean progenitors.

To assess species-level diversity in the didelphid marsupial genus Marmosops, we obtained sequence data from the mitochondrial cytochrome b (CYTB) gene from > 200 specimens, including exemplars of every currently recognized species together with multiple specimens of all geographically widespread forms. Analyses of these data using the general mixed Yule coalescent (GMYC) model suggest that the genus could be twice as speciose as currently recognized, but putative species identified by the GMYC criterion require careful evaluation using other data. To assess phylogenetic relationships within Marmosops, we additionally sequenced a large fragment of the breast cancer activating 1 (BRCA1) gene from one specimen each of the putative species identified by the GMYC analyses of CYTB. Maximum likelihood and Bayesian analyses of a concatenated gene (CYTB + BRCA1) matrix revealed a basal dichotomy between two ancient, morphologically diagnosable clades with apparently distinct distributions and adaptive phenotypes. We describe those clades as subgenera and assign 12 nominal taxa to Sciophanes subgen. nov. (with type species Marmosops parvidens) and 27 nominal taxa to the nominotypical subgenus (with type species Marmosops incanus).

Molecular information is crucial for species identification when facing challenging morphology‐based specimen identifications. The use of DNA barcodes partially solves this problem, but in some cases when PCR is not an option (i.e., primers are not available, problems in reaction standardization), amplification‐free approaches could be an optimal alternative. Recent advances in DNA sequencing, like the MinION device from Oxford Nanopore Technologies (ONT), allow to obtain genomic data with low laboratory and technical requirements, and at a relatively low cost. In this study, we explore ONT sequencing for molecular species identification from a total DNA sample obtained from a neotropical rodent and we also test the technology for complete mitochondrial genome reconstruction via genome skimming. We were able to obtain “de novo” the complete mitogenome of a specimen from the genus Melanomys (Cricetidae: Sigmodontinae) with average depth coverage of 78X using ONT‐only data and by combining multiple assembly routines. Our pipeline for an automated species identification was able to identify the sample using unassembled sequence data (raw) in a reasonable computing time, which was substantially reduced when a priori information related to the organism identity was known. Our findings suggest ONT sequencing as a suitable candidate to solve species identification problems in metazoan nonmodel organisms and generate complete mtDNA datasets.

Morphological character data are inadequate to resolve the evolutionary relationships of the didelphid genus Chacodelphys , which previous phylogenetic analyses have alternatively suggested might be the sister taxon of Lestodelphys and Thylamys (tribe Thylamyini) or of Monodelphis (tribe Marmosini) in the subfamily Didelphinae. Because fresh material of Chacodelphys is unavailable, we extracted DNA from microscopic fragments of soft tissue adhering to the 95-year-old holotype skull of C. formosa. Phylogenetic analyses of the resulting sequence data convincingly resolve Chacodelphys as the sister taxon of Cryptonanus , a genus with which it had not previously been thought to be closely related. This novel clade ( Chacodelphys + Cryptonanus ) belongs to an unnamed thylamyine lineage with Gracilinanus and Lestodelphys + Thylamys , but relationships among these taxa remain to be convincingly resolved. Los análisis basados en caracteres morfológicos han sido inadecuados para resolver las relaciones evolutivas del género marsupial didélfido Chacodelphys . Previos análisis filogenéticos han sugerido como hipótesis alternativas que Chacodelphys sea el grupo hermano de Lestodelphys y Thylamys (tribu Thylamyini) o de Monodelphis (tribu Marmosini), todos estos géneros pertenecientes a la subfamilia Didelphinae. Debido a la ausencia de material fresco de Chacodelphys , extrajimos ADN de fragmentos microscópicos de tejido adherido al cráneo de 95 años del holotipo de C. formosa . Análisis filogenéticos de las secuencias obtenidas resuelven convincentemente la posición filogenética de Chacodelphys como el taxón hermano de Cryptonanus , un género con el cual nunca antes se había pensado que estuviera cercanamente relacionado. Aunque reconocemos a este nuevo clado ( Chacodelphys + Cryptonanus ) junto con Gracilinanus y Lestodelphys + Thylamys pertenecientes a un linaje sin nombre, las relaciones entre estas taxa siguen sin estar convincentemente resueltas.

This is the first installment of a revision of the didelphid marsupial genus Philander, commonly known as gray four-eyed opossums. Although abundant and widespread in lowland tropical forests from southern Mexico to northern Argentina, species of Philander are not well understood taxonomically, and the current literature includes many examples of conflicting species definitions and nomenclatural usage. Our revision is based on coalescent analyses of mitochondrial gene sequences, phylogenetic analyses of mitochondrial and nuclear genes, morphometric analyses, and firsthand examination of relevant type material. Based on these results, we provisionally recognize eight species, of which three are formally treated in this report: P. quica (Temminck, 1824), an Atlantic Forest endemic formerly known as P. frenatus (Olfers, 1818); P. canus (Osgood, 1913), a widespread species formerly treated as a synonym or subspecies of P. opossum (Linnaeus, 1758); and P. pebas, a new species endemic to Amazonia. The remaining, possibly valid, species of Philander can be allocated to two clades. The first is a cis-Andean complex that includes P. andersoni (Osgood, 1913); P. mcilhennyi Gardner and Patton, 1972; and P. opossum. The second is a transAndean complex that includes P. melanurus (Thomas, 1899) and P. pallidus (Allen, 1901). Among other nomenclatural acts, we designate a neotype for the long-problematic nominal taxon Didelphis superciliaris Olfers, 1818, and (in an appendix coauthored by Renate Angermann), we establish that Olfers' coeval binomen D. frenata is based on an eastern Amazonian type and is a junior synonym of P. opossum.

No abstract

On the basis of our recent fieldwork and historical records, we document the diversity of small non-volant mammals in the northern end of Cordillera Central of Colombia, an important region in the context of vertebrate biodiversity. From February 2004 to February 2006, we completed mammal surveys in three localities at the department of Antioquia, with elevations ranging from 1650 to 2000 m. We recorded a total of 14 species: three marsupials, one shrew, one heteromyid, and nine sigmodontinae rodents, including three species endemic in Cordillera Central. The rodents Heteromys australis , Nephelomys pectoralis , and Rhipidomys latimanus were recorded in all localities. Nephelomys pectoralis was captured in all surveys and was the most abundant species. Nearby historical records exist for 16 species, seven of which were not captured during our surveys. The community of small mammals in the northern Cordillera Central has species richness similar or higher than that in other Andean localities with a broader elevational range. We show that small mammal communities from middle elevations are a mixture of middle elevation endemics and highland species, but with little contribution from the lowlands. Finally, the occurrence of endemic and threatened species in this region suggests its importance from a conservational and biogeographical standpoint for small terrestrial mammals.

PVUSET ACU isso Naty geet CR Rane aA ey fa OE Rae a pee gE CRA Paes aes gee PE Rae ee gee 9 3 TnteOodigiorig, {FRO eek eeepc ts ww eek BLL, ees eee CRIS, BP thes Pat eae aeee ALL, arene toe 3 Materials atid WViSthGasne, 6-Pinty acs ask 4ted ae gacneteng.aeereacn deed ast aalacnee hog aay! 42k 4ECcd abeanasacaroeg abReae-: Moleculgn-Anabysese-ee oa ia tere. BN ens ee a tee ed ay tae Rete Betis Les Daa wien et ee ae 18 PROCUUG AY. co BtT he OMS Co ot ae aL Cal eM te an Wiebe Une £ UG ah Meek pote da GU had ay WOT hee och 18 PSTSC US SEONG Ef Aon aoe sheses yee SN bedi apa eset ee Se HE av aa poset Ge bd ven arene ee ea Het ear aa ed 18 Camparative Morphologys 22a ¢ 355.75 tesindh 37s a hls SOTA OND TSS la Ae eGR aha e sah SGC Size. anc: External WvMorpHologyr 2 sl thats 2s Aedes ned akties pyeee etre ated fates Peas esting 8 Cranigdental Morphology stoi ete nL re a he cee las hee od adele ene dd PASO GIC AACCOIM Se, Bio tee Rose seems andr eee ateease enact ete oe te ashes ats Meeseruantebe cteranstnoace hares Ne aD DSA CPO UNI Ee co oles aerate ce yos paneeie gy ela Hp aittg Bae SHE Ete Gotcieed ne Fig ER CTS Marmosa (Micoufeus) rapposa Thomas, 1899) 5 sca Ve oye eee EY eed Pa ee le eed Marisa | Micoureus) parda' Tate, TOS To. acca, 4k fatness habs ag Sten bp wes he ae STA AB Leaf Marmosa (CMicoureus)-tuttert Thomas, 1924 ...o65 ben cay ieses oe 9454 CoA pio ah beg es PLCRTLOWIEGRIIOTITE Fc: cant h o5 ly aap ler at lle ge ecee ite was eet oe, Pataca ate ele enlace Releremicega se Whe mye ac) ders at cassis Pca eine =k $e abe asacale ioraatane ach Aerie ast cassaisbine deierta =) 4 ARP sacale torsatane 4294 POPDATELTSe amie nF ete ee Sey SUE Agta oe ee, Mey oP, Pee e ened ly Ah Celie Owe OMe Mey Oe gee PPCM 2a a eas hens ew ka sa vd Senet, sala Raa os gehts lne och 85 Su oe Seta tes oale Ee amas cee UPR TILIBG Belay S125 cee Ace we cS Wy locld en sate eset tg Sea stole aoe Goat eset Web aW $teld er rat Meaet shy Sat Hind weet Sy ABSTRACT In this report, the second of a revisionary series on mouse opossums (Marmosa), we analyze cytochrome b sequence data from 166 specimens of the subgenus Micoureus and delimit putative species using the multirate Poisson Tree Processes (mP'l'P) method. 'That analysis identifies 21 putative species, many of which can be matched with available names, including alstoni, constantiae, demerarae, limae, germana, meridae, paraguayana, parda, perplexa, phaea, rapposa, and rutteri, However, some of these nominal taxa are not morphologically diagnosable, and in the absence of other corroborating evidence, we do not recommend that they all be recognized as valid. Phylogenetic analyses of a multigene dataset suggest that putative species of Micoureus belong to several wellsupported clades, one of which (the "Rapposa Group") is revised in this report. As defined herein, the Rapposa Group includes at least three valid species: M. rapposa Thomas, 1899 (including budini Thomas, 1920); M. parda Tate, 1931; and M. rutteri Thomas, 1924. Herein we document their ecogeographic distributions and diagnost...