'Hobbit' specimens discovered on an Indonesian island suggest that our tiny ancient relatives dwarfed after reaching the remote land, according to a new study.

The island of Flores came to the world's attention in October 2004, when it was announced that the remains of previously unknown human species, the Homo floresiensis, widely referred to as "hobbits," were discovered in a cave.

The species, one of the last early human species to die out, stood about three-feet tall.

Scientists dated the 2004 Homo floresiensis fossils back to a time period between 95,000 to 50,000 years ago.

Two competing hypotheses emerged after the hobbit fossils were first discovered in 2004. Some scientists said the Homo floresiensis appeared to be a dwarfed descendant of the taller, earlier Homo erectus, and suggested that the species shrank because of its isolation on the island. Others theorized that the hobbits were descendants of a more archaic group.

Scientists are now releasing new research based on the discovery of even older fossils that were uncovered in Flores in 2014.

Two new papers published in the journal Nature on Wednesday document the 2014 discovery of a fragment of a jaw and six teeth from at least three small extinct hominini species. 

The new research suggests that the 700,000-year-old fossils lend themselves to the theory that the Homo floresiensis species evolved from the larger-bodied Homo erectus, an ancestor to modern humans.

Scientists say the specimens are considered the oldest human remains discovered on Flores and they're even smaller than the remains discovered a decade earlier.

Gerrit van den Bergh, a paleontologist at the University of Wollongong in Australia, says the latest discovery suggests that the ancestors of Homo floresiensis experienced extreme dwarfism on the island of Flores. 

He said the adult molar recently discovered on Flores has characteristics of Homo erectus ancestry, but that it's 20 per cent smaller in size.

"That adds crucial support to previous claims that the Homo floresiensis is indeed a kind of dwarfed Homo erectus," van den Bergh said during a press briefing on Tuesday.

He noted that fossil evidence discovered on continental archeological digs implies that the human body and brain size gradually increased during much of the Pleistocene Epoch. 

"Human diversity could have been far greater than we ever realized," van den Bergh added on the conference call.

Anthropologist Adam Brumm of Griffith University in Australia, who also studied the fossils and artifacts discovered on Flores, said he believes researchers will continue to find more fossil material on the island.

He theorized that a "freak event" such as a tsunami likely swept the Homo erectus from Asia and Africa and carried the species to Flores -- some which managed to survive the natural disaster.

"What we hope to find in the future are some leg bones, arm bones and in particular the wrist and the feet, which is where you really see this curious morphology of the Homo floresiensis appearing," Brumm said.

He said he's confident that scientists will soon be able to make a definite conclusion about the hobbit fossils.

"But so far we're putting our money on the fact that it's a very early version of the Homo floresiensis," Brumm said.