scholarly journals <i>Selenogonus narinoensis</i> Stirton, 1947 (Tayassuidae, Cetartiodactyla, Mammalia): taxonomic status and paleobiogeographic implications

Fossil Record ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 65-75
Author(s):  
Germán M. Gasparini ◽  
Oscar F. Moreno-Mancilla ◽  
José L. Cómbita
Keyword(s):  
Mandibular Condyle ◽  
Taxonomic Status ◽  
First Record ◽  
South American ◽  
Isthmus Of Panama ◽  
Morphological Studies ◽  
Great American Biotic Interchange ◽  
Species Inquirenda ◽  
Crown Morphology ◽  
New Interpretation

Abstract. The species Selenogonus narinoensis was described by Stirton (1947) based on a single specimen which comes from sediments cropping out in the Cocha Verde locality, Nariño Department (Colombia), tentatively referred to the late Pliocene–Pleistocene (MGN 931; IGM p002118, Museo Geológico Nacional, Servicio Geológico Colombiano, Bogotá). However, morphological studies and comparative morphometric observations of the specimen suggest that (1) no diagnostic character supports the validity of the species Selenogonus narinoensis (here considered species inquirenda); (2) a combination of features (e.g., the mandibular condyle located behind the posterior edge of the vertical mandibular ramus, the angular process which projects laterally outwards, a bunolophodont crown morphology, a mesodont crown height, and a simple crown morphology of the third lobe of m3) indicates it belongs to the genus Platygonus; (3) this specimen corresponds to one of the largest South American peccaries; (4) taking into account certain anatomical characters as well as its morphometric range, this specimen is assigned to Platygonus cf. marplatensis. Even though the stratigraphic provenance of the specimen is still doubtful, it can be proposed that (1) it could be one of the most ancient records of tayassuids in South America, as would be expected given its geographical position, and (2) considering the new taxonomic proposal, this specimen represents the first record of Platygonus cf. marplatensis in Colombia and represents one of the northernmost South American records of the genus. This new interpretation would be of great relevance in the Great American Biotic Interchange due to its strategic geographical proximity to the Isthmus of Panama.

Middle Pleistocene age of the fossiliferous sedimentary sequence from Tarija, Bolivia

2013 ◽  
Vol 79 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Bruce J. MacFadden ◽  
Peter K. Zeitler ◽  
Federico Anaya ◽  
John M. Cottle
Keyword(s):  
South America ◽  
New Age ◽  
Middle Pleistocene ◽  
South American ◽  
Sedimentary Sequence ◽  
The Past ◽  
Reference Sections ◽  
Great American Biotic Interchange ◽  
New Interpretation ◽  
Land Mammal

AbstractThe highly fossiliferous sediments of the Tolomosa Formation from Tarija, southern Bolivia, represent one of the most important localities in South America that documents the Great American Biotic Interchange. Over the past several decades, chronostratigraphic studies have indicated a middle Pleistocene age for the Tolomosa Formation from ~ 1.1 to 0.7 Ma. This interval correlates to the Ensenadan South American Land Mammal Age as it is characterized from classic localities in Argentina. Recently, however, a new interpretation based on AMS 14C ages indicates that the fossiliferous sediments from Tarija are latest Pleistocene, i.e., < 44 ka, and thus of Lujanian age. Here we report a new age of 0.76 ± 0.03 Ma (2σ) based on 11 U–Th/Pb and U–Th/He individual determinations from the Tolomosa Formation. This is indistinguishable from the age published from the same ash in 1983, and was originally used to calibrate the magnetostratigraphic section at Tarija. The new age confirms that the age of the Tolomosa Formation is middle Pleistocene, and not latest Pleistocene. The age of the Tarija Fauna has significant implications with regard to the stage of evolution biochronology for Pleistocene fossil mammals in South America, and in particular, the classic and important reference sections in Argentina.

scholarly journals Onthophagus pilauco sp. nov. (Coleoptera, Scarabaeidae): evidence of beetle extinction in the Pleistocene–Holocene transition in Chilean Northern Patagonia

ZooKeys ◽  
2021 ◽  
Vol 1043 ◽  
pp. 133-145
Author(s):  
Francisco Tello ◽  
José R. Verdú ◽  
Michele Rossini ◽  
Mario Zunino
Keyword(s):  
Dung Beetle ◽  
First Record ◽  
Morphological Characters ◽  
South American ◽  
Continental Scale ◽  
Northern Patagonia ◽  
Great American Biotic Interchange ◽  
Rapid Changes ◽  
Underlying Causes ◽  
New Evidence

The South American Pleistocene–Holocene transition has been characterized by drastic climatic and diversity changes. These rapid changes induced one of the largest and most recent extinctions in the megafauna at the continental scale. However, examples of the extinction of small animals (e.g., insects) are scarce, and the underlying causes of the extinction have been little studied. In this work, a new extinct dung beetle species is described from a late Pleistocene sequence (~15.2 k cal yr BP) at the paleoarcheological site Pilauco, Chilean Northern Patagonia. Based on morphological characters, this fossil is considered to belong to the genus Onthophagus Latreille, 1802 and named Onthophagus pilaucosp. nov. We carried out a comprehensive revision of related groups, and we analyzed the possible mechanism of diversification and extinction of this new species. We hypothesize that Onthophagus pilaucosp. nov. diversified as a member of the osculatii species-complex following migration processes related to the Great American Biotic Interchange (~3 Ma). The extinction of O. pilaucosp. nov. may be related to massive defaunation and climatic changes recorded in the Plesitocene-Holocene transition (12.8 k cal yr BP). This finding is the first record of this genus in Chile, and provides new evidence to support the collateral-extinction hypothesis related to the defaunation.

Tupinambine teiids from the middle Miocene of north-western Patagonia (Argentina)

2008 ◽  
Vol 29 (3) ◽  
pp. 425-431 ◽  
Author(s):  
Santiago Brizuela ◽  
Adriana María Albino
Keyword(s):  
Geographical Distribution ◽  
Middle Miocene ◽  
First Record ◽  
South American ◽  
The South ◽  
North Western

Abstract Remains of teiids assignable to the Tupinambinae (Tupinambis sp. or Crocodilurus sp.) are here described from the middle Miocene Collón Curá Formation at Cañadón del Tordillo, in Neuquén province, Argentina. No tupinambine species presently inhabits the region of the fossil locality. The fossils represent the westernmost distribution of fossil tupinambine teiids in Patagonia, enlarging the known geographical distribution of the teiids through the Miocene in a longitudinal range. Also, they constitute the first record of lizards from the Colloncuran SALMA, partially filling the record of tupinambine teiids for the South American Miocene.

scholarly journals An assessment of the taxonomic validity of three species of marsupial frogs (Anura: Hemiphractidae: Gastrotheca) from the Yungas of Bolivia based on external morphology and cranial osteology

Zootaxa ◽  
2021 ◽  
Vol 5068 (2) ◽  
pp. 211-239
Author(s):  
CLAUDIA LANSAC ◽  
RODRIGO AGUAYO ◽  
IGNACIO DE LA RIVA
Keyword(s):  
Principal Component ◽  
Taxonomic Status ◽  
Ct Scanning ◽  
Developmental State ◽  
Morphological Characters ◽  
Biological Entity ◽  
Nominal Species ◽  
Linear Discriminant ◽  
Morphological Studies ◽  
Cranial Osteology

The genus Gastrotheca (Anura: Hemiphractidae) is a group of marsupial frogs particularly diverse in Andean regions. Several taxonomic studies of this genus have been conducted in the humid cloud forests—or Yungas—of the Andean eastern slopes of central Bolivia (departments of Cochabamba and Santa Cruz). Yet, the distinction among three species that occur sympatrically in these forests, G. lauzuricae (proposed as a junior synonym of G. coeruleomaculatus in 2015), G. piperata, and G. splendens, remains unclear since the morphological characters that purportedly support their differentiation are variable and partly shared among them. We have carried out external morphological studies, including multivariate morphometric analyses, to assess how they support the taxonomic status of these three species. We also evaluated characters of the cranial osteology of a sample of six individuals using micro CT-scanning. Principal component and linear discriminant analyses resulted in a great overlap among the putative species. Cranial osteological comparisons did not reveal highly significant differences among them, but suggested that different degrees of hyperossification could be related to the developmental state of individuals. Our results indicate that most morphological and osteological reported differences between the three species likely represent intraspecific variation. Thus, we propose that the three nominal species belong to a single biological entity, for which the name Gastrotheca splendens (Schmidt, 1857) has priority. We also restrict the name Gastrotheca coeruleomaculatus (Werner, 1899) to externally similar congeneric populations from the Yungas forests of department of La Paz, but highlighting the need of a detailed evaluation of their taxonomic identity.  

scholarly journals Insecticide Resistance in Anopheles Albitarsis S.S. From a Rice Production Field, With the First Record of Kdr Mutation in This Species 

2021 ◽  
Author(s):  
Taiza Andrade Braga ◽  
Aline Cordeiro Loureiro ◽  
José Bento Pereira Lima ◽  
Ademir J Martins
Keyword(s):  
Insecticide Resistance ◽  
Taxonomic Status ◽  
First Record ◽  
Blood Feeding ◽  
Resistance Mechanisms ◽  
Field Population ◽  
Low Frequencies ◽  
Laboratory Colony ◽  
Field Samples ◽  
Rice Plantation

Abstract Background: Although there is a vast literature concerning insecticide resistance (IR) in Plasmodium vectors from African and Asian continents, similar studies with Neotropical anophelines are scares. Herein we evaluated the IR profile of Anopheles albitarsis s.s. of a laboratory colony and a natural population collected around a rice plantation field. The laboratory colony is original from a collection performed in this same region more than two decades ago. Methods: We collected An. albitarsis females while resting after blood feeding, around rice field plantations in Massaranduba, SC, Brazil. These females laid their eggs in the laboratory, and the larvae were raised in parallel with our lab colony. To be sure about the field samples’ taxonomic status, we amplified and sequenced the mitochondrial COI gene of a sampling of field captured mosquitoes. We performed a simplified knockdown test with larvae exposed to permethrin and deltamethrin and submitted adult females to a WHO like tube test with the pyrethroids permethrin, deltamethrin, and etofenprox, in addition to the organophosphate malathion. A segment of the voltage-gated sodium channel gene (NaV) was amplified and cloned. Based on the observed sequences, we developed a TaqMan genotyping assay for the variation L1014F and calculated the genotypic and allelic frequencies concerning this SNP in the field population.Results: The COI analyses confirmed the taxonomic status of An. albitarsis s.s in laboratory and field samples. The field population was resistant to pyrethroids but not to malathion. We observed the substitutions L1019R, F1020S, and the classical kdr L1014F in the NaV gene. This classical kdr allele was present under low frequencies in the overall field population (2%), although more frequent in pyrethroid-resistant insects.Conclusions: The An. albitarsis s.s. population from Massaranduba was resistant to pyrethroids, likely due to selection pressure exerted by agrochemical pesticides. We registered the classical kdr mutation in a Brazilian Anopheles species for the first time. Further investigations are necessary to disclose additional resistance mechanisms.

scholarly journals Distribution of the rare species of clingfishes — small-headed clingfish Apletodon dentatus (Actinopterygii, Gobiesocidae) — near Crimean coasts

2017 ◽  
Vol 2 (2) ◽  
pp. 41-48
Author(s):  
E. P. Karpova ◽  
A. R. Boltachev ◽  
O. N. Danylyuk
Keyword(s):  
New Species ◽  
Species Composition ◽  
Coastal Waters ◽  
Taxonomic Status ◽  
Population Characteristics ◽  
The Black Sea ◽  
Mediterranean Populations ◽  
Morphological Studies ◽  
Significant Difference ◽  
A New Species

Cryptobenthic fauna investigations are highly relevant at studying biodiversity of regions. Studies of the species composition of Gobiesocidae family were carried out in order to clarify ichthyofauna of different regions, and a new species for the Black Sea coastal zone of Crimea was found. Information about its morphology, biology, behavior and other characteristics is very important because of weak study and indeterminate taxonomic status of this species. As a result of morphological studies of the Crimean specimens no significant difference with the type of the Atlantic-Mediterranean populations has been proven. Naturalization of small-headed clingfish in coastal waters of Crimea has been confirmed and some population characteristics, such as a length-weight relationship, have been described. Peculiarities of habitat which which small-headed clingfish prefers and features of localization, enabling competitiveness have been identified. Identification keys were compiled and are given in the paper.

scholarly journals New records of the William’s Jerboa, Paralactaga cf. williamsi (Thomas, 1897) (Rodentia: Dipodidae) from northeastern Iran with notes on its ecology

Check List ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 1855 ◽  
Author(s):  
Kordiyeh Hamidi ◽  
Jamshid Darvish ◽  
Maryam M. Matin
Keyword(s):  
Species Identification ◽  
Cytochrome B ◽  
New Record ◽  
New Records ◽  
Taxonomic Status ◽  
First Record ◽  
External Morphology ◽  
Western Iran ◽  
Eastern Iran ◽  
Molar Teeth

Paralactaga williamsi, a five-toed jerboa, is known to occur in Anatolian Turkey, northern Lebanon, Armenia, Azerbaijan and western Iran. Here, we report the first record of this species in Kopet-Dag Mountains, northeastern Iran. Species identification was based on external morphology, skull and molar teeth morphology and morphometrics studies, as well as molecular an­al­yses. Brief notes on the ecology of the species are also provided. This new record expands the distribution of P. williamsi in Iran about 850 km eastward, however further sampling will be needed for a better judgment on the taxonomic status of this species in eastern Iran and to determine the patterns of its distribution. Since the specimen did not group with other P. williamsi in the cytochrome b analysis, we provisionally classify the specimens as P. cf. williamsi.

scholarly journals A new terrestrial snail species (Gastropoda: Bulimulidae) from the Región de Antofagasta, northern Chile

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3538
Author(s):  
Juan Francisco Araya ◽  
Abraham S.H. Breure
Keyword(s):  
New Species ◽  
Coastal Area ◽  
First Record ◽  
Coastal Areas ◽  
Snail Species ◽  
South American ◽  
Northern Chile ◽  
Terrestrial Snails ◽  
A New Species ◽  
Coastal Range

A new species of Scutalus Albers, 1850 (Gastropoda: Bulimulidae), Scutalus chango sp. n., is described from a coastal area of northern Chile. Empty shells of this new species were found buried in sand and under boulders and rocks in the foothills of the Chilean Coastal Range at Paposo, Región de Antofagasta. This new species is distinguished from all other Chilean terrestrial snails by its slender shell with a flared and reflected aperture, and by the presence of a columellar fold. This is the first record of Scutalus in Chile, and the southernmost record for this endemic South American bulimulid genus. The presence of this species in Paposo highlights the need for further research and for conservation guidelines in coastal areas of northern Chile, which have comparatively high levels of biodiversity and endemism.

scholarly journals Morphology and sexual dimorphism of living mature adults of Amphiduros fuscescens (Marenzeller, 1875) (Annelida, Hesionidae, Amphidurine), first reported for the Iberian Peninsula

2021 ◽  
Vol 9 ◽  
Author(s):  
Daniel Martin ◽  
Chiara Romano
Keyword(s):  
Sexual Dimorphism ◽  
Iberian Peninsula ◽  
Taxonomic Status ◽  
Single Species ◽  
First Record ◽  
The Body ◽  
Valid Species ◽  
Mature Adults ◽  
Nw Mediterranean ◽  
Cryptic Species Complex

To date, the genus Amphiduros (Annelida: Hesionidae: Amphidurine) is considered as monotypic. Its single species, Amphiduros fuscescens (Marenzeller, 1875), is well characterised by lacking proboscideal papillae and emerging acicular chaetae, as well as by having three antennae, eight pairs of tentacular cirri and inflated dorsal cirri with characteristic alternating length and colour (transparent, with median orange band and white tips) in live animals. Three specimens, one male and two females, were found below boulders at 5–7 m depth in Punta Santa Anna, Blanes and Cala Maset, Sant Feliu de Guixols (Catalan Sea, NW Mediterranean, Iberian Peninsula). Our finding allowed us to describe different, unreported morphological traits and lead us to support the existence of sexual dimorphism (in terms of colouring, cirri morphology and distribution of sexual products along the body). Despite A. fuscescens having been previously reported from the Atlantic and the Mediterranean (particularly in SE French coasts), the specimens from Blanes represent the first record of the species from the Iberian Peninsula. In addition, our molecular results strongly support that Amphiduros pacificus Hartman, 1961 from California (currently synonymised with A. fuscescens) requires to be re-described and reinstalled as a valid species. In turn, our morphological observations support suggesting all other non-Mediterranean reports of A. fuscescens, including the species still under synonymy (i.e. Amphidrornus izukai Hessle, 1925 and Amphidromus setosus Hessle, 1925) as likely being a cryptic species complex whose the taxonomic status requires further assessment.

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