Life History Consequences of Sexual Dimorphism in a Chernetid Pseudoscorpion

Ecology ◽  
1987 ◽  
Vol 68 (5) ◽  
pp. 1495-1501 ◽  
Author(s):  
David W. Zeh
1990 ◽  
Vol 68 (7) ◽  
pp. 1366-1373 ◽  
Author(s):  
Jeffrey M. Howland ◽  
Laurie J. Vitt ◽  
Pamela T. Lopez

An Amazonian population of the iguanid lizard Uranoscodon superciliosum was studied in lowland tropical wet forest in central Pará, Brazil. These nonheliothermic lizards are restricted to densely vegetated habitats near (often over) water, particularly riverbanks and small forest streams, where they utilize small-diameter perches and feed on a wide variety of invertebrates, apparently at the water's edge. They mature at moderate to large size at an age of about 1.5 years. Production of moderate-sized clutches of eggs is seasonal, and reproduction and fat storage both cycle in association with rainfall and flooding. Although they occur in fairly high densities, social interaction is uncommon and sexual dimorphism is not pronounced. The ecology and life history of this lizard seem to be strongly influenced by the unusual habitat specialization.


2004 ◽  
Vol 71 (sup2) ◽  
pp. 117-120 ◽  
Author(s):  
Elena Marzona ◽  
Daniele Seglie ◽  
Cristina Giacoma

Evolution ◽  
2016 ◽  
Vol 70 (2) ◽  
pp. 342-357 ◽  
Author(s):  
Martyna K. Zwoinska ◽  
Martin I. Lind ◽  
Maria Cortazar-Chinarro ◽  
Mark Ramsden ◽  
Alexei A. Maklakov

1986 ◽  
Vol 64 (10) ◽  
pp. 2192-2196 ◽  
Author(s):  
Akira F. Peters ◽  
Dieter G. Müller

Life histories of two ligulate forms of Desmarestia with different phylloid width from one site on the Canadian Pacific coast were studied in culture. Meiospores from a form with narrow phylloids germinated into monoecious gametophytes. Meiospores from a form with broad phylloids developed into dioecious gametophytes, showing sexual dimorphism characteristic for dioecious species of Desmarestia. The two growth forms also differed in culture conditions required for gametogenesis. We conclude that at least two different species of ligulate Desmarestia occur on the Pacific coast of North America.


2009 ◽  
Vol 29 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Yen-Nien Cheng ◽  
Robert Holmes ◽  
Xiao-Chun Wu ◽  
Noel Alfonso

2016 ◽  
Vol 18 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Christopher M. Martinez ◽  
F. James Rohlf ◽  
Michael G. Frisk

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 103-112 ◽  
Author(s):  
P. M. Sander

Abstract. Sauropod dinosaurs present exceptional challenges in understanding their biology because of their exceptional body size. One of these, life history, can be inferred from the histology of their bones. For this purpose, the diverse sauropod assemblage of the Upper Jurassic Tendaguru beds was sampled with a new coring method which provided unprecented access to and insights into sauropod bone histology. Growth series of humeri and femora as well as long growth records from single bones suggest that all four sauropod taxa are characterized by continued growth after sexual maturity but that growth was determinate. Fibrolamellär bone is dominant in the samples, indicating that the bones of the Tendaguru sauropods grew at rates comparable to those of modern large mammals. The growth pattern of these sauropods thus combines typically reptilian traits with typically mammalian traits. In the details of their bone histology, the Tendaguru sauropod taxa show considerable variation which reflects life history. In addition, Barosaurus exhibits probable sexual dimorphism in bone histology. Das Verständnis der Biologie der sauropoden Dinosaurier wird durch ihre enorme Körpergröße außerordentlich erschwert. Allerdings kann ein Aspekt, die Lebensgeschichte, anhand der Histologie ihrer Knochen untersucht werden. Zu diesem Zweck wurde die diverse Sauropoden-Vergesellschaftung der oberjurassischen Tendaguru-Schichten beprobt, und zwar mit einer neuartigen Kernbohrmethode, die einen herausragenden Zugang und Einblick in die Knochenhistologie der Sauropoden ermöglichte. Wachstumsserien von Humeri und Femora sowie umfassende Überlieferungen des Wachstums von Individuen anhand einzelner Knochen machen es wahrscheinlich, daß alle vier Sauropoden-Taxa der Tendaguru-Schichten durch ein auch nach der Geschlechtsreife anhaltendes Wachstum gekennzeichnet waren. Allerdings ging das Wachstum nicht bis zum Tode des Tieres weiter, sondern kam bei einer etwas variablen Maximalgröße zum Stillstand. Fibrolamellärer Knochen ist der vorherrschende Knochentyp in den Proben, was anzeigt, daß die Tendaguru-Sauropoden mit für Säugetieren typische Raten wuchsen. Die Tendaguru-Sauropoden kombinerten also ein für Reptilien typisches Muster des Wachstums, nämlich nach der Geschlechtsreife anhaltendes Wachstum, mit für Säuger typischen Raten des Wachstums. Die verschiedenen Sauropoden-Taxa zeigen erstaunliche Unterschiede in den Details ihrer Knochenhistologie, die Unterschiede in der Lebensgeschichte belegen. Bei Barosaurus scheint außerdem ein Geschlechtsdimorphismus in der Histologie der Langknochen vorzukommen. doi:1002/mmng.1999.4860020107


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