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New world coralsnakes of the genus Micrurus are a diverse radiation of highly venomous and brightly colored snakes that range from North Carolina to Argentina. Species in this group have played central roles in developing and testing hypotheses about the evolution of mimicry and aposematism. Despite their diversity and prominence as model systems, surprisingly little is known about species boundaries and phylogenetic relationships within Micrurus, which has substantially hindered meaningful analyses of their evolutionary history. Here we use mitochondrial genes together with thousands of nuclear genomic loci obtained via ddRADseq to study the phylogenetic relationships and population genomics of a subclade of the genus Micrurus: The M. diastema species complex. Our results indicate that prior species and species-group inferences based on morphology and color pattern have grossly misguided taxonomy, and that the M. diastema complex is not monophyletic. Based on our analyses of molecular data, we infer the phylogenetic relationships among species and populations, and provide a revised taxonomy for the group. Two non-sister species-complexes with similar color patterns are recognized, the M. distans and the M. diastema complexes, the first being basal to the monadal Micrurus and the second encompassing most North American monadal taxa. We examined all 13 species, and their respective subspecies, for a total of 24 recognized taxa in the M. diastema species complex. Our analyses suggest a reduction to 10 species, with no subspecific designations warranted, to be a more likely estimate of species diversity, namely, M. apiatus, M. browni, M. diastema, M. distans, M. ephippifer, M. fulvius, M. michoacanensis, M. oliveri, M. tener, and one undescribed species.
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http://dx.doi.org/10.1016/j.ympev.2020.106770 | DOI Listing |
Anat Rec (Hoboken)
August 2025
Área de Paleontología, Unidad Ejecutora Lillo, CONICET, Fundación Miguel Lillo, Tucumán, Argentina.
A new baurioid therocephalian, Jiucaiyuangnathus confusus, was recently described from the Lower Triassic Jiucaiyuan Formation of Jimusar, Xinjiang, China. Here, two or three newly collected specimens from the same horizon of Turpan, Xinjiang, including a complete skull with lower jaw and partial skeletons, are referred to this species. The new skull is slightly larger than that of the holotype.
View Article and Find Full Text PDFAnat Rec (Hoboken)
July 2025
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
In various domestic mammals, smaller breeds tend to have proportionally larger teeth, whereas this is not a universal trend across mammals. This suggests that body size can evolve faster than tooth size, leading to the prediction that tooth-body size scaling differs among closely related versus distant taxa. Here, we test this pattern in a new computed tomography (CT)Skriffer Utgitt au det Norske Vidensk-Akad scan dataset on 302 adult domestic rabbits of various breeds (maxilla and mandible) and compare this to 198 literature data from 20 nondomestic lagomorph species (maxilla only).
View Article and Find Full Text PDFFolia Med (Plovdiv)
February 2025
Medical University of Varna, Varna, Bulgaria.
The faculty of speech in humans is a distinguishing trait that sets them apart from all other biological species. Speech production is typically achieved through the processes of phonation and articulation. The acoustic method of studying speech is an individual auditory approach based on hearing as a biological analyzer.
View Article and Find Full Text PDFAnat Rec (Hoboken)
January 2025
Instituto de Plasmas e Fusão Nuclear & Centro de Recursos Naturais e Ambiente (CERENA), Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Hypercanines, or hypertrophied canines, are observed in a wide range of both extinct and extant synapsids. In non-mammaliaform cynodonts, the Permo-Triassic forerunners of mammals, long canines are not uncommon, appearing in several unrelated taxa within the clade. Among them is Trucidocynodon riograndensis, a carnivorous ecteniniid cynodont from the Late Triassic of Brazil, which exhibits a specialized dentition, including spear-shaped incisors, very long and narrow canines, and sectorial postcanines with distally oriented cusps, all of which have finely serrated margins.
View Article and Find Full Text PDFJ Hum Evol
November 2024
NYCEP Morphometrics Group, USA; Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, 1830 East Monument St, 3rd Floor, Baltimore, MD 21287, USA.
Here we describe new fossil material of Antillothrix bernensis, a Pleistocene-Holocene primate taxon from Hispaniola. It is now represented by seven crania, five mandibles, and dozens of postcranial elements from several paleontologically rich cave systems. The five adult crania included here share a similar overall profile as well as specific features such as a deep depression at the glabella.
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