A 160,000-year-old fossil found 60 miles west of Marrakech, Morocco, are believed to be the oldest human to have a long childhood.

An international team of scientists, using synchrotron X-ray light, studied the teeth of an eight-year-old child that died 160,000 years ago and found microscopic growth lines within the tooth suggesting development like that of a modern human.

The dental growth lines reveal development in a similar way to annual rings in trees and so reveal growth rates accurately after thousands of years.

Tooth growth in the Moroccan child was compared with other fossils and living humans to reveal the modern condition of prolonged dental development in childhood.

The researchers stated: "These findings are not in contrast with our current wisdom that suggest that an extended period of development, and, by implication, childhood, may be linked to the origins of social, biological, and cultural changes needed to support dependent children with greater opportunities for early childhood learning."

Scientists from the Max Planck Institute for Evolutionary Anthropology, the Laboratory of Geobiology, Biochronology and Human Paleontology in Poitiers , the European Synchrotron Radiation Facility, the UK's School of Dental Sciences in Newcastle, the Research School of Earth Sciences in Canberra and from the Department of Geology of the Mohammed V-Agdal University in Rabat in Morocco all took part in the research.