An Organelle's Help in Dinosaur Puzzle

Forms of the melanosome organelle suggest colored, iridescent feathers, were present in dinosaur-era birds, according to an article by Thomas Carannant on the Science World Report website.

The birds of the dinosaur era were previously thought to have little color variation, according to an older (2011) National Geographic article. 

Melanosomes produce and transport melanin, a pigment that gives animal cells color and protects them from the sun.

Carannant explains that the shapes of the melanosomes recently analyzed from fossils resemble those that are known to produce brown, black and gray pigments in modern bird lineages and also cause iridescence. This suggests that the feathered Amniota emerged around the same evolutionary era, during the age of Dinosaurs.  

Photo credit: Li, et al (original article from Nature Magazine), "Melanosome diversity across Amniota." The tree diagram at the bottom shows the proposed evolutionary relationships while the scatter plots show the observed patterns in size (diameters and lengths).

  
The tree of life is revised again, thanks to an organelle. The question remains whether this fits in with most of the accepted taxonomy or changes it completely.