Spiral-toothed fossil mystery solved

By Ella Davies,  Reporter, BBC Nature

An ancient spiral-toothed fish has been reconstructed from fossil evidence by scientists.

US researchers used CT scans to build a computer model of what Helicoprion looked like and how it ate.

They were also able to resolve a continuing puzzle over whether the unique saw-like spirals were located inside or outside the mouth.

The findings show the animals were more closely related to modern chimaeras, or ratfish, than sharks.

The study is published by researchers from Idaho State University in the Royal Society journal Biology Letters.

The university's Museum of Natural History has the largest public collection of fossilised Helicoprion in the world.

The fish lived 270 million years ago but because they were largely formed from cartilage, which does not preserve well, their fossil record comprises unusual spiral structures.

Referred to as "whorls", these features have been compared to spiralling saw blades and have puzzled the scientific community for over a century.

Continued:  http://www.bbc.co.uk/nature/21589719

Archer fish spitting mystery solved, scientists say

Italian scientists say they have solved the mystery of how archer fish can spit powerful jets of water.

Archer fish shoot water jets with enough force to knock prey into the water from overhanging vegetation.

Research by a team from the University of Milan shows that the fish's forceful strike is formed externally using water dynamics, rather than using the body's internal muscles.

This technique allows the animals to take accurate shots from up to 2m away.

For years scientists studied archer fish (Toxotes jaculatrix), searching for evidence of specialised internal organs that are adapted to this water-pistol-like hunting technique.

But previous studies have ruled out this idea.

Continued:  http://www.bbc.co.uk/nature/20068607

Painted lady migration secrets unveiled - 9000 miles to Africa and back

Migration much longer than America's Monarch butterflies

October 2012. One of the longest standing mysteries of migration has finally been solved after scientists discovered where the UK's Painted Lady butterfly population goes each autumn. The butterfly, a common immigrant, migrates from the continent each summer to UK shores in varying numbers. But up until now scientists did not know if the Painted Lady made the return journey at the end of the summer, like the closely related Red Admiral, or simply died in the UK.

In one of the largest citizen science projects ever conducted, scientists from Butterfly Conservation, the NERC Centre for Ecology & Hydrology and Rothamsted Research amongst others, have discovered exactly what happens to Painted Ladies each autumn.

More than 60,000 public sightings of the butterfly during 2009 were collected across Europe including radar images tracking butterfly movements across southern England with 10,000 British observers taking part.

High altitude migration
Scientists discovered that the Painted Lady did indeed migrate south each autumn but made this return journey at high altitude out of view of butterfly observers on the ground. Radar records revealed that Painted Ladies fly at an average altitude of over 500 metres on their southbound trip and can clock up speeds of 30 mph by selecting favourable conditions.

9000 mile round trip
The findings also revealed that the species undertakes a phenomenal 9,000 mile round trip from tropical Africa to the Arctic Circle - almost double the length of the famous migrations undertaken by Monarch butterflies in North America.

Continued:  http://www.wildlifeextra.com/go/news/painted-lady-migration.html