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Monday, March 21st, 2022
| Time | Event | ||||
| 1:08a | [PaleoMammalogy • 2022] Spinal Fracture reveals An Accident Episode in Eremotherium laurillardi (Xenarthra, Megatheriidae) shedding light on the Formation of A Fossil Assemblage
Abstract The Toca das Onças cave is one of the most important Quaternary mammal deposits of Brazil. Two different hypotheses have been proposed to explain the preservation mode of its skeletal remains: either the animals climbed down into the cave, or it could have functioned as a natural trap. Evaluation of pathological modifications on three articulated vertebrae of a single adult giant ground sloth Eremotherium laurillardi reveals a particular type of bone fracture caused by compressive force on the vertebral column, which split the vertebral bodies in the sagittal plane. This diagnosis suggests that the animal accidentally fell into the cave, in accordance with the second hypothesis proposed to the incorporation mode of skeletal remains into the cave.
Eremotherium laurillardi Lund 1842 Fernando H. de S. Barbosa, Hermínio I. de Araújo-Júnior, Isadora da Costa, André Vieira de Araújo and Edison Vicente Oliveira. 2022. Spinal Fracture reveals An Accident Episode in Eremotherium laurillardi shedding light on the Formation of A Fossil Assemblage. Scientific Reports. 12: 4119. DOI 10.1038/s41598-022-08107-1 | ||||
| 1:24a | [Ichthyology • 2022] Tembeassu titanicus • Systematics of Neotropical Electric Knifefish Tembeassu (Gymnotiformes, Apteronotidae)
Abstract A new species of the poorly known and critically endangered ghost knifefish Tembeassu is described from the upper Paraná and Araguari rivers, Brazil, using external anatomy and X-ray microcomputed tomography (µCT scan). Tembeassu titanicus sp. nov. is distinguished from its sole congener, T. marauna, by a unique set of morphometric and meristic characters, in addition to the absence of a tooth patch at the anterior portion of the roof of the oral cavity and the external corner of the mouth slightly passing the vertical through the posterior margin of the posterior nare. To test the monophyly of Tembeassu and reassess its phylogenetic position, a total-evidence approach was performed through a Bayesian inference (BI) and maximum-parsimony analysis (MP). Our results indicate that Tembeassu is monophyletic and the sister taxon of a clade formed by Apteronotus s.s., Megadontognathus, and Parapteronotus (BI); or as part of a large polytomy at the base of Apteronotidae (MP). Species of Tembeassu co-occur in the Paraná River basin, and the absence of the patch of accessory teeth in T. titanicus sp. nov. may indicate that this species accesses a different food resource, and also putatively occupies a different habitat than T. marauna. Comments on the evolution of the mandibular lobe in Gymnotiformes, dentition pattern in Tembeassu, and apteronotid diversity in the Paraná River are provided. Keywords: Anatomy, Bayesian inference, new species, phylogeny, sympatry, taxonomy    Tembeassu titanicus sp. nov. Luiz A. W. Peixoto, Ricardo Campos-da-Paz, Naércio A. Menezes, C. David De Santana, Mauro Triques and Aléssio Datovo. 2022. Systematics of Neotropical Electric Knifefish Tembeassu (Gymnotiformes, Apteronotidae). Systematics and Biodiversity. 20(1); 1-19. DOI: 10.1080/14772000.2022.2032460 | ||||
| 1:25a | [Botany • 2022] Hornstedtia albomucronata (Zingiberaceae) • A New and Unusual Ginger Species from Zamboanga Peninsula, Philippines
Abstract A collection of a ginger from Zamboanga Peninsula, Philippines, superficially resembles Hornstedtia but is very different from all other known Philippine species especially by the elongate rachis and absence of sterile bracts. Furthermore, it does not match any other species elsewhere. In order to ascertain its generic placement, phylogenetic analyses using ITS and trnK/matK regions were conducted revealing a close relationship with H. tomentosa from Borneo, Java and Sumatra. The mystery species, H. tomentosa and the type of Hornstedtia are placed within a highly supported clade. Morphologically, it is similar to H. tomentosa having an elongate rachis with red bracts and yellow flowers but differs by the swollen and white mucro to the fertile bract, presence of a bracteole and the petaloid labellum. As a result, Hornstedtia albomucronata, is described as a new species here, and illustrations and information on its distribution, habitat, phenology and provisional IUCN conservation status are provided. An updated key to the nine Hornstedtia species in the Philippines is included. Keywords: endangered, Hornstedtia, ITS, phylogeny, trnK/matK, Zamboanga, Zingiberaceae   Hornstedtia albomucronata Docot, Mazo & Mendez Rudolph Valentino A. Docot, Kean Roe F. Mazo, Noe P. Mendez and Axel Dalberg Poulsen. 2022. Using Molecular Data to Test the Generic Placement of A New and Unusual Ginger Species from the Philippines. Nordic Journal of Botany. DOI: 10.1111/njb.03573 Researchgate.net/publication/359213814_a | ||||
| 12:07p | [Herpetology • 2020] Stenocercus diploauris & S. nigrobarbatus • Two New Sympatric Species of Stenocercus (Iguania: Tropiduridae) from the inter-Andean Valley of the Mantaro River, Peru
Abstract We describe two new sympatric species of Stenocercus from the seasonally dry forest of the inter-Andean valley of the Mantaro River (Huancavelica department) in the Central Andes of central-southern Peru, at elevations of 1,693 to 2,920 m asl. Stenocercus diploauris sp. nov. is similar to S. formosus and S. ochoai, but differs in having a longitudinal neck fold and C-shaped nuchal mite pocket around the oblique fold and posteriorly limited by the antehumeral fold. Stenocercus nigrobarbatus sp. nov. is similar to S. frittsi and S. variabilis, however it can be distinguished by having a postfemoral mite pocket with one or more vertical folds or ridges and by the presence, in adult males, of a continuous black patch covering the infralabials, throat, chest, ventral surfaces of forelimbs, belly (as a midventral line), ventral surfaces of hind limbs, and pelvic region. Keywords: Reptilia, Andes, Huancavelica department, lizard, mite pocket, morphology, seasonally dry forest   Pablo J. Venegas, Lourdes Y. Echevarría, Luis A. García-Ayachi and Caroll Z. Landauro. 2020. Two New Sympatric Species of Stenocercus (Squamata: Iguania) from the inter-Andean Valley of the Mantaro River, Peru. Zootaxa. 4858(4); 555–575. DOI: 10.11646/zootaxa.4858.4.5 |
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