Jul 11, 2007
The Lucy skeleton is one of the most famous human ancestors
The cache included several complete jaws and one partial skeleton, and was unearthed at Woranso-Mille in the country's Afar desert.
The remains were recovered 30km from the site where "Lucy" - one of the most famous human ancestors - was found.
The specimens have been dated to between 3.5 and 3.8 million years ago.
The research team is led from Cleveland Museum of Natural History in the US.
The palaeontologists have been working in northern Ethiopia's Afar region for four seasons. This year, they have broadened their search to new areas.
They have found these new areas rich in fossils including teeth and fragments of jawbones belonging to ancient, humanlike creatures - often referred to as hominids.
Dr Yohannes Haile-Selassie, one of the team's leaders, told the BBC: "One of the reasons why this discovery is really important is because it serves as a time frame that we know nothing about in the past and that's what makes it really significant."
He added: "We have a record of about six million years of early human evolution in Ethiopia, but there are also small gaps here and there and this one happens to be one of them."
The fossils come from the right time period to shed light on the relationship between the "Lucy" species, Australopithecus afarensis, and an even older species called Australopithecus anamensis.
The older species is thought to be ancestral to the "Lucy" hominids, but scientists need more fossils to say this for sure.
Dr Haile-Selassie said the new dig sites yielded the bones of many monkeys, antelopes and wild pigs, suggesting that the hominids lived in a far greener and more wooded countryside than the bare stony Afar desert region seen today.