NEEDLE & GLOBE

Differently shaped melanosomes contain differently coloured pigments

Excerpts from this BBC article:

A team of scientists from China and the UK has now revealed that the bristles of this 125 million-year-old dinosaur were in fact ginger-coloured feathers.

The researchers say that the diminutive carnivore had a “Mohican” of feathers running along its head and back. It also had a striped tail.

The team revealed details of the dinosaur’s coloured feathers in an article published on Nature’s website.

The team began by studying the fossilised remains of a bird, Confuciusornis, which also lived during the early cretaceous period.

Confuciusornis’ feathers were preserved in extraordinarily complete fossils that were recently discovered in northern China.

Using a powerful electron microscope to look inside the feathers, researchers were able to see microscopic structures called melanosomes, which, in life, contain the pigment melanin.

Sinosauropteryx had a "Mohican" of ginger feathers and a stripy tail

This gives more weight to a very well-supported theory that modern birds evolved from theropods, the group of small carnivorous dinosaurs to which Sinosauropteryx belonged.

“This discovery suggests that with more work we may be able to accurately reconstruct colour patterns in some dinosaur species, and begin to understand how those colour patterns may have functioned for camouflage or display.”

Excerpts from this BBC article:

Monarch butterflies that migrate vast distances have grown larger bodies and wings, researchers have discovered.

These “supersized” butterflies have evolved to cope with the demands of long-distance flight.

In contrast, monarchs that live in one place all year have wings that are up to 20% smaller, report scientists in the journal Evolution.

Monarch butterflies undergo the longest recorded two-way migration of any insect.

Up to four generations of monarch butterfly complete a round trip of up to 8,000km, flying between northern US and Canada and Mexico in search of warmer temperatures.

But the new study is one of the first to show that populations within the same species can also evolve differently-shaped wings depending on their lifestyle.

“We were surprised that average wing size differences between migratory and non-migratory monarchs were so striking and consistent,” says Professor Sonia Altizer of the University of Georgia, in Athens, US.

“Mexico’s Cave of Crystals stunned geologists when it was first discovered in 2000. The underground chamber contains some of the largest natural crystals ever found – some of the selenite structures have grown to more than 10m long. Professor Iain Stewart got a rare glimpse of the subterranean spectacle while filming for the new BBC series How the Earth Made Us.”

An amazing video, and further details from the BBC article are here.