Washington, D.C.

Ancient skeleton likely even older

A new dating technique suggests that a humanlike fossil skeleton found in South Africa was buried about 4 million years ago, which makes it one of the oldest known hominid discoveries.

That’s 1 million years earlier than previously thought.

The nearly complete skeleton came from caves that contain rich deposits of remains from the prehuman branches of the ancestral tree that led to modern humans.

Skeleton fossils unearthed in 1997 were age-dated near 3 million years using a technique that measured the changes in the Earth’s magnetic field. The results were disputed by experts who said the method was not precise.

In the new effort, researchers measured the decay of isotopes in cave sediments to establish the older ages. A report on their study appears today in the journal Science.

Washington, D.C.

Nissan to replace some Altima air bags

Nissan Motor Co. will offer to replace air bags in some 198,000 older-model Altimas because of complaints that they deploy too forcefully and have injured passengers’ eyes.

As a result, federal safety regulators on Thursday closed their investigation of the 1994 and early 1995 Altima air bags without issuing a conclusion about whether they are defective.

Nissan’s agreement to offer owners free installation of less-powerful air bags “sufficiently addresses the safety concerns,” the National Highway Traffic and Safety Administration said in paperwork closing the 2-year-old case.

The Altima investigation found 79 complaints of facial or eye injuries from passenger-side air bags. There were “far more claims” of moderate or serious eye injury than in similar cars, the agency said.