A skin-deep dinosaur issue

One always wonders about dinosaurs and their lives. So, did they peel or shed their skins too ? Presumably, said Mark A Norell, chairman of the division of paleontology at the American Museum of Natural History. But not all at once.

“Since we can’t directly observe extinct animals, we need to look at close relatives,” Mark said. “Birds are living dinosaurs, crocodilians their closest relatives. Both shed skin in patches and strips, not entire skins like snakes.”

“Because crocodiles and birds share a common ancestor, we predict this skin-shedding style was present in that ancestor,” he continued. “Non-bird dinosaurs descend from this same ancestor. Without other information, we predict that even giant dinosaurs
exfoliated their dead dry skin in patches.”

Everything that has skin sheds it, Mark emphasised, but there is a tremendous
diversity in how skin sheds. In humans, for example, rubbing the dry skin of an arm across something black leaves a white scuff of dead skin cells, he said. And in birds, skin dries and sloughs off as small patches, like peeling after a bad sunburn.

Reptile shedding usually conjures visions of whole snakeskins, shed as a continuous piece, “looking like the ghost of a living serpent,” Mark said. But this is an anomaly; most animals do it differently. Typical reptiles – lizards, crocodiles and turtles – shed dry, irregular skin patches, and that is probably how dinosaurs did it, he said.

A starling picnic, with gusto
Starlings eat a lot of things, including fruits, grains, seeds and garbage, but one of their favourite foods is the larva of the European crane fly, Tipula paludosa, which feeds on the roots of grasses. Starlings are known to form flash mobs and attack infested turf in a feeding frenzy.

The familiar starling and the crane fly, which resembles a large mosquito and is also known as the leatherjacket, are introduced species. The crane fly was probably imported accidentally in infested potting soil, but the bird, Sturnus vulgaris, was brought to North America on purpose.

All the millions of starlings in North America are believed to be descended from a few birds released in Central Park in the 1890s in a romantic attempt by the amateur biologist Eugene Schieffelin to populate the United States with every bird mentioned by Shakespeare.

Eugene and others may also have hoped that the energetic feeding habits of
starlings would make them useful in pest control, but the jury is out. In one study in Washington state, starlings feasted on crane fly larvae but reduced the total by only 7 per cent, though other studies have found them to be locally effective.
C Claiborne Ray

Beetle found, no sign of relatives
A newly identified beetle species in the wetlands of South Africa has no direct relatives on the continent, a new study reports.“To the uninitiated, it looks like yet
another black beetle,” said David Bilton, an aquatic biologist at Plymouth University in England and an author of the report, published in Systematic Entomology. “The thing that’s interesting about this one is that it doesn’t have any relatives in the whole of South Africa.”

The diving beetle, Capelatus prykei, is about two-fifths of an inch long – large compared with other diving beetles. Although diving beetles are found worldwide in ponds, lakes, rivers and streams – there are more than 4,000 species –DNA analysis revealed that the new species has no relatives in Africa. “It’s closest relatives are in Australia and New Guinea, and in the Mediterranean,” David said.

The beetle lives in the fynbos, an ecosystem in the Western Cape of South Africa. The climate is similar to the Mediterranean’s, with wet winters and long, dry summers, contributing to great biodiversity. The region has also been climatically stable for about nine million years, making extinctions rare. The researchers know of only one living
population of Capelatus, in Table Mountain National Park in South Africa. Other populations may have died out because of urban development, David said.
Sindya N Bhanoo
NYT