The known diversity of dart-poison frog species has grown from 70 in the 1960s to 247 at present, with no sign that the discovery of new species will wane in the foreseeable future. Although this growth in knowledge of the diversity of this group has been accompanied by detailed investigations of many aspects of the biology of dendrobatids, their phylogenetic relationships remain poorly understood. This study was designed to test hypotheses of dendrobatid diversification by combining new and prior genotypic and phenotypic evidence in a total evidence analysis. DNA sequences were sampled for five mitochondrial and six nuclear loci (approximately 6,100 base pairs [bp]; x¯ = 3,740 bp per terminal; total dataset composed of approximately 1.55 million bp), and 174 phenotypic characters were scored from adult and larval morphology, alkaloid profiles, and behavior. These data were combined with relevant published DNA sequences. Ingroup sampling targeted several previously unsampled species, including Ar...

Phylogenetic systematics of dart-poison frogs and their relatives (amphibia: athesphatanura: dendrobatidae)

P.A. Sims, D.G. Mann and L.K. Medlin. 2006. Evolution of the diatoms: insights from fossil, biological and molecular data.Phycologia 45: 361–402. DOI: 10.2216/05-22.1Molecular sequence analyses hav...

/pdf/evolution-of-the-diatoms-insights-from-fossil-biological-and-1yu5ukpsz5.pdf

Evolution of the diatoms: insights from fossil, biological and molecular data

Presented herein is the first morphological analysis of turtle relationships to examine the monophyly of many turtle groups by using only single species as terminals and by integrating a large number of primitive fossil taxa. The data matrix consists of 136 osteological parsimony informative characters with 169 derived character states for 45 fossil and 22 living species of the clade Testudinata. The results corroborate the monophyly of a large number of previously hypothesized clades, but refute the accepted hypothesis regarding the basal split of living turtles. In particular, the primitive turtles Proterochersis robusta, Kayentachelys aprix, Mongolochelys efremovi, Meiolania platyceps, and Kallokibotion bajazidi are removed from their current position as crown turtles and placed along the phylogenetic stem of this clade. The age of the turtle crown is thereby adjusted from the Late Triassic to the Late Jurassic, which is relevant to testing molecular clock hypotheses. This revised topology has...

Phylogenetic Relationships of Mesozoic Turtles

This review discusses body size and mass as they relate to the Orthoptera (crickets, katydids, grasshoppers) and the Phasmatodea (walkingsticks). It addresses the expression, causes and consequences of size in these insects. Topics include: methodological problems in body-size research, gravity vs surface forces, allometry and scaling, Dyar's law, ontogenetic scaling, size-invariant traits and nonallometric scaling, the influence of size on physiology, function, behavior, life history, mating, fecundity, population dynamics, ecology, and community, size-clines, Bergmann's rule, sexual size dimorphism, Rensch's rule, protandry, the environmental, genetic, and physiological control of size, the evolution of size and the influence of size on evolution. Hypotheses are presented to explain why insects remain small in comparison to other taxa.

/pdf/the-significance-of-body-size-in-the-orthoptera-a-review-im4aibcue0.pdf

The significance of body size in the Orthoptera: a review

Protohadros byrdi, gen. et sp. nov., from the Cenomanian Woodbine Formation, Texas, is described on the basis of a disarticulated skull and isolated postcrania. The possession of the fewest synapomorphies among hadrosaurids places Protohadros at the basal position within Hadrosauridae. The combination of a derived maxillopalatal unit and a primitive quadrate indicate a level of cranial kinesis intermediate between primitive iguanodontians and other hadrosaurids. Both the phylogenetic and chronological distributions of these characteristics describe an evolutionary sequence of adaptations in which modifications for increased masticatory ability of the maxillary region precede the evolution of both streptostylic cranial kinesis and a more derived mandible in Hadrosauridae. The taxon is unique among hadrosaurids in possessing a ventrally deflected muzzle, including a deep, rostrally massive mandible, that is interpreted to represent an exclusively low-browsing pattern of food acquisition in a deltai...

A new species of basal hadrosaurid (Dinosauria, Ornithischia) from the Cenomanian of Texas

Proceedings of the Academy of Natural Sciences of Philadelphia

The Travels of Sir John Mandeville : the Version of the Cotton Manuscript in Modern Spelling.

Letters and Other Writings of James Madison, Fourth President of the United States

Histoire Naturelle des Poissons

Bibliographical History of Electricity and Magnetism

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