Browsing by Autor "Marcos Maximiliano Paz"

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Description and phylogeny of a new species of Liolaemus (Iguania: Liolaemidae) endemic to the south of the Plurinational State of Bolivia
(Public Library of Science, 2019) Cristian Simón Abdala; Álvaro J. Aguilar-Kirigin; Romina Valeria Semhan; Ana Lucia Bulacios Arroyo; Julián Valdés; Marcos Maximiliano Paz; Roberto Gutiérrez; Pablo Valladares Faúndez; Robert Langstroth; James Aparicio
The Liolaemus montanus group is a diverse group of lizards that ranges from central Peru to southwestern Mendoza, Argentina, including much of the Plurinational State of Bolivia ("Bolivia") and Chile. The species of this group mainly inhabit high elevation areas with cold temperatures. In the last years, several species of this group have been described, mostly in Argentina and Chile. In Bolivia, there are at least thirteen valid species belonging to the L. montanus group. In this study, we describe a new species of the L. montanus group with a marked endemism in the Cordillera de Sama of the Tarija Department, Bolivia, and a combination of unique character states that allows its formal description as a new species. The phylogenetic relationships based on analysis of 159 morphological characters suggest that it belongs to the L. montanus group, and that it is closest to Liolaemus pulcherrimus, which is found allopatrically in a small area of the Jujuy Province, Argentina. The multivariate analyses of 66 morphological characters support the phylogenetic relationships. Statistical analyses of inter-species comparisons of morphological characters are not considered the only methods due to the non-independence of some characters states among species; thus, a phylogenetic analysis is recommended. The detailed revision of specimens of the L. montanus group held in the collections of Bolivia is filling major geographic gaps and improving our understanding of the phylogenetic and biogeographic relationships of this widely distributed group of South American lizards.
Female Reproductive Tract and Dynamics of the Only Unisexual Lizard of Pleurodonta (Iguania: Liolaemidae)
(2024) Marcos Maximiliano Paz; Noelia García; Álvaro J. Aguilar-Kirigin; Cristian Simón Abdala
Liolaemus parthenos es la única especie unisexual en toda Pleurodonta. Se conjetura que esta lagartija es partenogenética, sin embargo, su ciclo sexual y aspectos ecológicos y anatómicos inherentes a su reproducción son desconocidos. El objetivo principal de este estudio fue proporcionar información sobre la progresión mensual de las gónadas durante el período activo de esta especie. Se describieron características anatómicas del tracto genital en ejemplares con diferente condición reproductiva. El ciclo sexual de L. parthenos es estacional, con actividad gonadal concentrada entre primavera y verano. Los ovarios y oviductos alcanzan su máximo desarrollo en octubre al inicio de la primavera. Mediante microscopía electrónica de barrido se reconocieron cinco regiones anatómicas y ultraestructurales en el oviducto, y en ninguna de ellas se constató la presencia de espermatozoides. Se describió el ciclo de cuerpos grasos abdominales para estimar la inversión energética destinada a la reproducción. El peso de estos órganos presentó un patrón de variación inverso a las gónadas, siendo la reproducción el proceso que consumió la mayor parte de sus grasas seguido por la brumación. Este trabajo aporta información novedosa que amplía el conocimiento sobre biología reproductiva del género Liolaemus. El mismo indica que L. parthenos posee un patrón reproductivo similar a otros Squamata de clima templado, con una dinámica gonadal conservada respecto a las especies ovíparas del grupo de L. darwinii, clado al cual pertenece. No obstante, el origen hibrido y condición unisexual de esta lagartija plantean nuevos interrogantes y la necesidad de mayores estudios reproductivos como identificar especies parentales, y constatar si la reproducción depende o no del esperma para iniciar la embriogénesis.
Increasing knowledge of the denizens of saline environments through integrative taxonomy: new Argentinian endemic taxa of<i>Liolaemus</i>(Iguania: Liolaemidae) and their evolutionary relationships
(Taylor & Francis, 2021) Cristian Simón Abdala; Marcos Maximiliano Paz; Romina Valeria Semhan; Noelia García; Álvaro J. Aguilar-Kirigin; Marı́a Eugenia Farı́as; Pablo Valladares; Roberto Gutiérrez; Matías Quipildor; Julián Valdés
The known diversity of the genus Liolaemus continues to increase, principally due to its great degree of endemism, the increasing number of researchers working on it, and advances in the taxonomic and phylogenetic knowledge of the genus. This diversity positions Liolaemus as the second most species-rich tetrapod genus. The present work adds to evidence for the great diversity of Liolaemus through the description of two new species, endemic to saline environments in the Argentinian Puna. Both species are members of the Liolaemus montanus group within the subgenus Eulaemus. To determine the taxonomic status of these lizards, we used integrative taxonomy as a tool, incorporating phylogenetic, morphological, and molecular genetic evidence, as well as the anatomy of hemipenes, statistical morphological analysis, and ecological characteristics. Our analyses supported the conclusion that both sampled populations of lizards are species new to science. One of these is found along the margins of the Antofalla salt flats in the Catamarca Province and the Hombre Muerto salt flats in the Salta Province. The other new species inhabits saline habitats vegetated by Lycium humile, principally between the salt crusts of the Antofalla salt flats. Both species are small to medium sized and can be distinguished from all other species of the L. montanus group by unique combinations of morphological characters, primarily pholidosis and dorsal and ventral colour patterns.urn:lsid:zoobank.org:act:29B39613-3298-4B43-A13A-9F950051BD04urn:lsid:zoobank.org:act:A97A5AA8-7295-4882-9809-CEFAD72E7202
Unravelling interspecific relationships among highland lizards: first phylogenetic hypothesis using total evidence of the Liolaemus montanus group (Iguania: Liolaemidae)
(Oxford University Press, 2019) Cristian Simón Abdala; Andrés Sebastián Quinteros; Romina Valeria Semhan; Ana Lucia Bulacios Arroyo; James A. Schulte; Marcos Maximiliano Paz; Mario R. Ruiz‐Monachesi; Alejandro Laspiur; Álvaro J. Aguilar-Kirigin; Roberto Gutiérrez
Abstract The South American lizard genus Liolaemus comprises &gt; 260 species, of which &gt; 60 are recognized as members of the Liolaemus montanus group, distributed throughout the Andes in central Peru, Bolivia, Chile and central Argentina. Despite its great morphological diversity and complex taxonomic history, a robust phylogenetic estimate is still lacking for this group. Here, we study the morphological and molecular diversity of the L. montanus group and present the most complete quantitative phylogenetic hypothesis for the group to date. Our phylogeny includes 103 terminal taxa, of which 91 are members of the L. montanus group (58 are assigned to available species and 33 are of uncertain taxonomic status). Our matrix includes 306 morphological and ecological characters and 3057 molecular characters. Morphological characters include 48 continuous and 258 discrete characters, of which 70% (216) are new to the literature. The molecular characters represent five mitochondrial markers. We performed three analyses: a morphology-only matrix, a molecular-only matrix and a matrix including both morphological and molecular characters (total evidence hypothesis). Our total evidence hypothesis recovered the L. montanus group as monophyletic and included ≥ 12 major clades, revealing an unexpectedly complex phylogeny.