scholarly journals Reacquisition of the lower temporal bar in sexually dimorphic fossil lizards provides a rare case of convergent evolution

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Tiago R. Simões ◽  
Gregory F. Funston ◽  
Behzad Vafaeian ◽  
Randall L. Nydam ◽  
Michael R. Doschak ◽  
...  
Keyword(s):  
Convergent Evolution ◽  
Rare Case ◽  
Sexually Dimorphic ◽  
Fossil Lizards

Corrigendum to: Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Vol 34 (8) ◽  
pp. 906
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

scholarly journals The tiny Cretaceous stem-bird Oculudentavis revealed as a bizarre lizard

2020 ◽  
Author(s):  
Arnau Bolet ◽  
Edward L. Stanley ◽  
Juan D. Daza ◽  
J. Salvador Arias ◽  
Andrej Čerňanský ◽  
...  
Keyword(s):  
Forest Ecosystem ◽  
Fossil Record ◽  
Convergent Evolution ◽  
Rare Case ◽  
Phylogenetic Placement ◽  
New Interpretation

AbstractOculudentavis khaungraae was described based on a tiny skull trapped in amber. The slender tapering rostrum with retracted osseous nares, large eyes, and short vaulted braincase led to its identification as the smallest avian dinosaur on record, comparable to the smallest living hummingbirds. Despite its bird-like appearance, Oculudentavis showed several features inconsistent with its original phylogenetic placement. Here we describe a more complete, specimen that demonstrates Oculudentavis is actually a bizarre lizard of uncertain position. The new interpretation and phylogenetic placement highlights a rare case of convergent evolution rarely seen among reptiles. Our results re-affirm the importance of Myanmar amber in yielding unusual taxa from a forest ecosystem rarely represented in the fossil record.

Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

scholarly journals Convergent evolution of sex-specific leg ornaments in Drosophilidae – from cells to structures

2019 ◽  
Author(s):  
K. Tanaka ◽  
O. Barmina ◽  
J. H. Massey ◽  
A. Kopp
Keyword(s):  
Convergent Evolution ◽  
Phylogenetic Reconstruction ◽  
Sexually Dimorphic ◽  
Developmental Constraint ◽  
Cellular Mechanisms ◽  
Cellular Processes ◽  
The Face ◽  
Male Specific ◽  
Novel Structures ◽  
Female Abdomen

AbstractSexually dimorphic morphological traits are among the fastest evolving animal features. Similar sex-specific structures have sometimes evolved independently in multiple lineages, presumably as targets of parallel sexual selection. In such cases, comparing the cellular mechanisms that generate these structures in different species can elucidate the interplay between selection and developmental constraint in evolution. In Drosophilidae, male-specific tarsal brushes on the front legs are found in at least four separate lineages. In this study, we combine phylogenetic reconstruction with developmental analyses and behavioral observations to investigate the evolutionary origin of these structures. We show that the sex brush has evolved independently at least three times from sexually monomorphic ancestral morphology. However, all sex brushes have very similar fine structure and develop through indistinguishable cellular processes, providing a striking example of developmental convergence. In all examined species, males use their sex brushes to grasp the female abdomen prior to copulation. We discuss potential reasons why convergent evolution of novel structures is rare even in the face of similar functional demands.

Identification of Pulmonary Deposits from a Sandpaper Worker: A Study by Electron Microscopy and X-Ray Microanalysis

1982 ◽  
Vol 40 ◽  
pp. 52-53
Author(s):  
S. K. Peng ◽  
M.A. Egy ◽  
J. K. Singh ◽  
M.B. Bishop
Keyword(s):  
Electron Microscopy ◽  
Environmental Pollution ◽  
Rare Case ◽  
Interstitial Fibrosis ◽  
X Ray ◽  
Documented Case ◽  
Etiologic Agents ◽  
Pulmonary Interstitial Fibrosis ◽  
Gold Miners ◽  
Pulmonary Changes

Electron microscopy and energy dispersive x-ray microanalysis (EDXA) are found to be very useful tools for identification of etiologic agents in pneumoconiosis or interstitial pulmonary disorders. Pulmonary interstitial fibrosis and granulomatosis are frequently associated with occupational and environmental pollution. Numerous reports of pneumoconiosis in various occupations such as coal and gold miners are presented in the literature. However, there is no known documented case of pulmonary changes in workers in the sandpaper industry. This study reports a rare case of pulmonary granulomatosis containing deposits from abrasives of sandpaper diagnosed by using EDXA.

Androgen-induced plasticity at a “vocal” neuromuscular synapse

1994 ◽  
Vol 52 ◽  
pp. 32-33
Author(s):  
Darcy B. Kelley ◽  
Martha L. Tobias ◽  
Mark Ellisman
Keyword(s):  
Xenopus Laevis ◽  
Motor Neurons ◽  
Sexual Differentiation ◽  
Molecular Basis ◽  
Neuromuscular Synapse ◽  
Sexually Dimorphic ◽  
Intracellular Protein ◽  
Developmental Program ◽  
Androgen Action ◽  
Clawed Frog

Brain and muscle are sexually differentiated tissues in which masculinization is controlled by the secretion of androgens from the testes. Sensitivity to androgen is conferred by the expression of an intracellular protein, the androgen receptor. A central problem of sexual differentiation is thus to understand the cellular and molecular basis of androgen action. We do not understand how hormone occupancy of a receptor translates into an alteration in the developmental program of the target cell. Our studies on sexual differentiation of brain and muscle in Xenopus laevis are designed to explore the molecular basis of androgen induced sexual differentiation by examining how this hormone controls the masculinization of brain and muscle targets.Our approach to this problem has focused on a highly androgen sensitive, sexually dimorphic neuromuscular system: laryngeal muscles and motor neurons of the clawed frog, Xenopus laevis. We have been studying sex differences at a synapse, the laryngeal neuromuscular junction, which mediates sexually dimorphic vocal behavior in Xenopus laevis frogs.

Abstract #736: A Rare Case of an Ectopic Parathyroid Adenoma Mimicking a Parathyroid Carcinoma

2015 ◽  
Vol 21 ◽  
pp. 143
Author(s):  
Elizabeth Sanchez Rangel ◽  
Maria Moscoso Cordero ◽  
Vinuta Mohan ◽  
Tasneem Zahra
Keyword(s):  
Parathyroid Adenoma ◽  
Parathyroid Carcinoma ◽  
Rare Case ◽  
Ectopic Parathyroid Adenoma ◽  
Ectopic Parathyroid

Abstract #110: Hemorrhagic Subdiaphragmatic Bronchogenic Cyst Mimicking an Adrenal Tumor: a Rare Case

2015 ◽  
Vol 21 ◽  
pp. 6
Author(s):  
Roy Guinto ◽  
Michele Ledoux ◽  
Alicia Williams ◽  
Anthony Mark
Keyword(s):  
Rare Case ◽  
Adrenal Tumor ◽  
Bronchogenic Cyst
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