Post by themechabaryonyx789 on Feb 13, 2014 22:00:47 GMT
www.sciencedaily.com/releases/2014/02/140212132753.htm "Date: February 12, 2014 Source: University of Texas at Austin Summary: New research revising rules on deciphering color in dinosaurs may provide a tool for understanding the evolutionary emergence of flight and changes in dinosaur physiology. While surveying melanosome shape in fossil and extant specimens, a research team unexpectedly discovered that ancient maniraptoran dinosaurs, paravians, and living mammals and birds uniquely shared the evolutionary development of diverse melanosome shapes related to color. The similarity could relate to a key shift in dinosaurian physiology."
And the journal that was linked with that article: "Inference of colour patterning in extinct dinosaurs1, 2, 3 has been based on the relationship between the morphology of melanin-containing organelles (melanosomes) and colour in extant bird feathers. When this relationship evolved relative to the origin of feathers and other novel integumentary structures, such as hair and filamentous body covering in extinct archosaurs, has not been evaluated. Here we sample melanosomes from the integument of 181 extant amniote taxa and 13 lizard, turtle, dinosaur and pterosaur fossils from the Upper-Jurassic and Lower-Cretaceous of China. We find that in the lineage leading to birds, the observed increase in the diversity of melanosome morphologies appears abruptly, near the origin of pinnate feathers in maniraptoran dinosaurs. Similarly, mammals show an increased diversity of melanosome form compared to all ectothermic amniotes. In these two clades, mammals and maniraptoran dinosaurs including birds, melanosome form and colour are linked and colour reconstruction may be possible. By contrast, melanosomes in lizard, turtle and crocodilian skin, as well as the archosaurian filamentous body coverings (dinosaur ‘protofeathers’ and pterosaur ‘pycnofibres’), show a limited diversity of form that is uncorrelated with colour in extant taxa. These patterns may be explained by convergent changes in the key melanocortin system of mammals and birds, which is known to affect pleiotropically both melanin-based colouration and energetic processes such as metabolic rate in vertebrates4, and may therefore support a significant physiological shift in maniraptoran dinosaurs."
Hatzegopteryx: That's not even the beginning, the whole forum is disturbingly lethargic.
Jun 14, 2014 15:49:29 GMT
Spinosaurus Maroccanus: I'm quite surprised how no one has touched the Argentina 97ma thread
Jun 14, 2014 15:20:28 GMT
Hatzegopteryx: This forum needs some serious attention; I'll be at it for a moment, unless I get other tasks that do not allow me to do so.
Jun 6, 2014 19:13:55 GMT
Hatzegopteryx: It's a genetic fallacy. It's basically an argument that intends to discredit the opponent's position by asserting the opponent's failure to act consistently in accordance with that position.
May 26, 2014 20:47:51 GMT