Hominin Playboys: Ancient Footprints in Tanzania Reveal Austrolopithecus Afarensis was Polygynous

Archaeologists have uncovered a set of footprints in Laetoli in northern Tanzania, which reveals that pre-human species that belongs to the Australopithecus afarensis species, could have mated with different females.

According to a new study, published in the journal eLife, the archaeologists have discovered 13 footprints, which belonged to Lucy, the famous human ancestor. The new set of footprints add to the 70 footprints discovered by paleontologist Mary Leakey in 1978, National Geographic reports.

Australopithecus lineage lived in Africa 2.9 to 3.8 million years ago and is considered as one of the possible ancestors of human beings, Live Science reports. The newly discovered tracks were estimated to be 3.66 million years old.

The set of footprints showed that male hominin's size were extremely different from their female counterparts. Research shows that in polygynous populations, males evolve larger than females due to intense competition, which means that hominin males could have had multiple partners.

"It is amazing that, almost four decades after the original discovery, we have new footprints from the very same sediments. They could have been made on the same day millions of years ago," said William Jungers, a paleoanthropologist who was not involved in the study, told Live Science.

The team notes that the newly discovered footprints could have been made during the same time as that of the footprints that Leakey discovered. They were found 490 meters from where Leakey found the other footprints and were surrounded by other animal footprints from giraffes, rhinos and guinea fowls.

"For me, the most important implication is that the area might harbor more ichnofossils— knowledge that could be used to solve many problems regarding different aspects of hominins," said Fidelis Masao, lead author of the study.