20 | NewScientist | 11 September 2010

IS IT a shark with legs? No, it’s a new species of dinosaur with a mysterious fin.

Concavenator corcovatus, which belonged to the theropod group of dinosaurs, has a pair of vertebrae five times longer than the others, which protrude midway along its back to make a triangular fin. “We’ve no idea what it is for,” says Francisco Ortega of the National University

of Distance Education in Madrid and head of the team that found the skeleton in Las Hoyas, Spain (Nature, DOI: 10.1038/nature09181).

“The back fin is just plain weird,” says Roger Benson at the University of Cambridge. Some later species of theropod had head crests and sails on their backs, he adds, which may have been used for signalling or display. Ortega

Iron overload may boost Alzheimer’s

IRON overload may accelerate Alzheimer’s disease, according to research that also reveals the role of beta-amyloid precursor protein (APP), which forms plaques in affected brains.

Jack Rogers at the University of Melbourne, Australia, and colleagues, used mouse studies, healthy human brain cells and post-mortems to show that APP’s role is probably to flush toxic iron from neurons. But in Alzheimer’s, the APP’s function is sabotaged by zinc, which accumulates in the disease’s trademark plaques (Cell, DOI: 10.1016/j.cell.2010.08.014).

Normally, zinc aids neuronal signalling, but as it becomes trapped in plaques, it both disrupts APP’s iron-clearing role and denies neurons the zinc they need for signalling. The outcome is a double-whammy which sees iron continuing to accumulate and neurons losing their ability to signal appropriately.

Insect brains outsmart hospital superbugs

EXTRACTS from the brains of locusts and cockroaches can kill hospital superbugs. Work is under way to identify the active ingredients, which could ultimately result in the first antibiotics originating from insects.

Nine distinct chemical extracts from the locust brain killed Escherichia coli, which can cause food poisoning, and seven killed Methicillin-resistant Staphylococcus aureus (MRSA), the problematic superbug sweeping hospitals and communities throughout the western world.

Researchers screened brains, along with other tissues, for antibacterial activity on the grounds that the brain is

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The humpback of the Cretaceous suspects the bones supported a hump that stored energy as fat.

Equally intriguing, the dinosaur may have had bird-like feathers. Its forearm bones have knob-like recesses that could have held feather quills. This pushes back the emergence of theropods with bird-like feathers by some 50 million years. “This is hugely significant as it’s the first good evidence for feather-like structures in a primitive theropod lineage,” says Benson.

the most vital organ for locusts to protect. “Without [the brain] they die, whereas they can survive losing limbs such as legs,” says Simon Lee of the University of Nottingham, UK. “From the locust’s point of view, it’s important that the central nervous system is protected all the time against bacteria and other pathogens,” he says. As he expected, only brain extracts were active.

Lee is currently conducting further analyses to identify the active components of the extracts, thought to be proteins because they stopped working when exposed to protein-degrading enzymes. He has also shown that the extracts don’t harm human cells. “But we’re a long way from these being active drugs,” he says.

Lee reported his findings this week at a meeting of the UK’s Society for General Microbiology in Nottingham.

A MAJOR extinction is under way – but predicting which species will survive could be harder than we thought. That’s the conclusion of one of the most accurate analyses ever of diversity in the marine animal fossil record.

Previously, it was thought that a group of animals that has diversified rapidly will later diversify more than others after a mass extinction. If true, this would help predict the outcome of the current extinction.

Now an analysis of 20,181 genera of marine fossils over 50 time periods by John Alroy of Macquarie University in Sydney, Australia, contradicts this principle. “The important overall pattern is no pattern,” says Alroy (Science, DOI: 10.1126/science.1189910).

Our unpredictable extinction

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