Colouring in the Dinosaurs, Dino Death Pits, Twin Moons Separated at Birth, Homing in on Echolocation, Plants and Pollinators, Baboon Infanticide


 

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Colouring in the Dinosaurs

orange-dinosaur.jpg Artist's rendition of how Sinosauropteryx might have appeared. (Chuang Zhao and Lida Xing)

Modern birds come in a wide variety of colours. And since we now think some species of dinosaur had feathers like modern birds, there has been speculation that perhaps dinosaur feathers came in a vivid assortment of hues as well. Unfortunately, fossils generally paint a black and white picture of dinosaurs. Now researchers, including Dr. Patrick Orr, from the School of Geological Sciences at University College Dublin, think they may have found clues to these hues. They found structures preserved within fossil feathers that they think are melanosomes. In modern birds, these contain coloured pigments, and their shape differs depending on their colour. This suggests that the species of dinosaurs they studied had black, grey, brown and orange colours in their plumage. Further study may suggest they dressed in colours beyond earth tones.

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Dinosaur Death Pits

death_pit.jpg Fossil from the death pit - courtesy Royal Tyrell Museum

While doing work in Northeastern China in 2001, Dr. David Eberth, the Senior Research Scientist at the Royal Tyrrell Museum in Drumheller, Alberta, discovered a pit containing stacked skeletons of different kinds of theropod dinosaurs. Four years later, he'd found two more very similar pits, both with up to nine stacked skeletons of theropods. After an investigation of the area's geographic features, he realized the pits were actually 150 million-year-old footprints of the 20-ton Sauropod. It was able to punch through the crust of volcanic ash that covered the mainly soft and swampy area. The pits filled in with softer material, undetected by the much smaller theropods who simply fell in and were not able to get out. The muddy conditions of these pits have resulted in the remarkable preservation of the theropod skeletons.

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Twin Moons Separated at Birth

moon-insides.jpg Artist's reconstruction of the interior of Ganymede and Callisto, courtesy NASA

Callisto and Ganymede, the two outermost great moons of Jupiter, should be twins. They're the same size, and they formed at the same time, of the same material. They are, however, quite different. Ganymede has a rocky core surrounded by ice, a magnetic field, and a surface that shows considerable geological activity. Callisto is a ball of mixed ice and rock, which seems to have been dead since it formed billions of years ago. Dr. Amy Barr, a senior research scientist at the Planetary Science Directorate of the Southwest Research Institute in Boulder, Colorado, thinks she knows why the moons are so different. She thinks Ganymede, which is a little closer to Jupiter than Callisto, is interesting because of the difficult childhood it suffered as a result by being smashed by comets and asteroids 3.8 billion years ago. Callisto, apparently, escaped.

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Homing In on Echolocation

bat.jpg Vampire Bat, courtesy Brock Fenton

A key to unlocking the mystery of echolocation in bats has been identified by researchers including Dr. Brock Fenton at the University of Western Ontario. Echolocation allows bats to navigate their way in the dark at high speed and intercept their insect prey with precision accuracy. A bone that connects the larynx to the bones that support the eardrum has been identified. It is called the stylohal bone. All bats have it, but it is only connected in bats that echolocate by using their larynx. For this reason, the find is also important in understanding the evolution of echolocation in bats.

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Plant Punishes a Presumptuous Pollinator

tobacco_pollinator.jpg Hummingbird feeding on tobacco flower - Credit: Danny Kessler, Max Planck Institute for Chemical Ecology

In every relationship there has to be a reasonable give and take, or the disadvantaged partner may go looking for greener grass. What's true in humans turns out to be true in plants. Dr. Ian Baldwin, director of the Max Planck Institute for Chemical Ecology in Jena, Germany has been looking at a plant that switches to a new pollinator if its old one does it wrong. The plant is normally pollinated at night by a moth, but the moth can lay very hungry caterpillars on the plant, which can devour the plant's leaves. Dr. Baldwin has found that if too many caterpillars take advantage of the plant, it will switch the timing of the its flowering to the daytime, when the moth is inactive but hummingbirds can pollinate it.

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Sharing - for the Children

chacma_male.jpg
Male Chacma baboon, copyright D. Gordon E. Robertson, cc-by-sa-3.0

Dominant male Chacma Baboons have a little problem. With the stress of leading their troop, and all the other males challenging their position, they likely won't be dominant for long. And when they're replaced, the new dominant male will try to kill all their infant offspring, so that the nursing females will become fertile again as soon as possible. Dr. Peter Henzi, a professor of psychology at the University of Lethbridge in Alberta, has found out what the dominant male does to try and give his offspring a fighting chance when he finally loses his position. The dominant male will allow subordinate males to mate occasionally, so they have infants in the troop as well. This means the subordinates have an investment in protecting infants, thus giving some protection to the dominant's orphans when he's gone.

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Theme music bed copyright Raphaël Gluckstein.
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