Latest Articles from Vertebrate Zoology Latest 2 Articles from Vertebrate Zoology https://vertebrate-zoology.arphahub.com/ Fri, 29 Mar 2024 06:49:10 +0200 Pensoft FeedCreator https://vertebrate-zoology.arphahub.com/i/logo.jpg Latest Articles from Vertebrate Zoology https://vertebrate-zoology.arphahub.com/ Novel type of egg-clustering in threadsnakes (Serpentes: Leptotyphlopidae) https://vertebrate-zoology.arphahub.com/article/108402/ Vertebrate Zoology 73: 691-696

DOI: 10.3897/vz.73.e108402

Authors: Mariana Chuliver, Agustín Scanferla

Abstract: Abstract Snakes lay their eggs in clutches of different size, which are usually attached to each other forming a cluster. Egg-clustering is a widespread phenomenon across alethinophidian snakes, mostly recorded in Pythonoidea and caenophidian clades. Here we report a new type of egg-clustering for threadsnakes (Leptotyphlopidae) that departs from the alethinophidian type. We found that females of Epictia australis and Leptotyphlops sylvicolus lay their eggs connected to each other through a filament, and we dubbed it ‘string-egg clustering’. The histomorphology of the filament linking the eggs in E. australis showed an outer calcareous layer underlain by a thick layer of collagen fibers, demonstrating that it is an integral part of the eggshell formed during its deposition process in the oviduct. String egg-clustering seems to be present only among species belonging to both subfamilies of threadsnakes, Epictinae and Leptotyphlopinae. Egg-clustering in alethinophidians has been demonstrated to have several advantages for embryo development and post-hatching survival, including fixing the position of the embryo within the egg, protection against predators, and embryo-to-embryo communication. The presence of a filament connecting the eggs in leptotyphlopid species might be relevant for maintaining the position of the embryo in the egg, to avoid the dispersion of the egg in the nesting site, and potentially for the transmission of physical cues. Thus, we hypothesize that the string-egg clustering constitutes an advantageous reproductive trait among threadsnakes.

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Research Article Tue, 12 Sep 2023 13:09:13 +0300
An evolutionary paradox on threadsnakes: Phenotypic and molecular evidence reveal a new and remarkably polymorphic species of Siagonodon (Serpentes: Leptotyphlopidae: Epictinae) from Amazonia https://vertebrate-zoology.arphahub.com/article/98170/ Vertebrate Zoology 73: 345-366

DOI: 10.3897/vz.73.e98170

Authors: Angele Martins, Manuella Folly, Guilherme Nunes Ferreira, Antônio Samuel Garcia da Silva, Claudia Koch, Antoine Fouquet, Alessandra Machado, Ricardo Tadeu Lopes, Roberta Pinto, Miguel Trefaut Rodrigues, Paulo Passos

Abstract: Threadsnakes are known for their conserved external morphology and historically controversial systematics, challenging taxonomic, biogeographic and evolutionary researches in these fields. Recent morphological studies—mostly based on µCT data of the skull and lower jaw—have resolved systematic issues within the group, for instance leading to the description of new taxa or re-positioning little-known scolecophidian taxa in the tree of life. Herein we describe a new polymorphic species of the genus Siagonodon from Amazonia based on morphological (external, osteology and hemipenis) and molecular data, and provide the first hemipenial description for the genus. We also reassign Siagonodon acutirostris to the genus Trilepida based on osteological data in combination with molecular evidence. The new species described represents an evolutionary paradox for scolecophidians because the species displays a remarkable variation in the shape of the snout region that is otherwise always highly conserved in this clade. Finally, this study reinforces the importance of protected areas as essential in maintaining vertebrate populations, including those that are not yet formally described.

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Research Article Mon, 10 Apr 2023 13:39:43 +0300