A new study has revealed that the ancestors of the so-called "hobbits," an early human species discovered on the Indonesian island of Flores, were even smaller than previously thought.
Published in Nature Communications on Tuesday, the study provides new insights into these diminutive hominins, whose fossils were first unearthed two decades ago.
The original fossils were discovered 20 years ago and named Homo floresiensis after the island of Flores.
They depicted a species that stood around 3 1/2 feet (1.07 meters) tall.
These small-statured humans quickly earned the nickname "hobbits."
New fossil finds from the nearby site of Mata Menge, located about 45 miles from the original discovery, suggest that their ancestors were even shorter.
The recent discovery includes a small adult limb bone dating back 700,000 years, which is much older than the original Homo floresiensis fossils, previously dated between 60,000 and 100,000 years ago.
The study's co-authors, Yousuke Kaifu from the University of Tokyo and Adam Brumm from Griffith University's Australian Research Centre for Human Evolution, highlight that this newly discovered bone is the smallest upper arm bone ever found in the hominin fossil record.
"This very rare specimen confirms our hypothesis that the ancestors of Homo floresiensis were extremely small in body size; however, it is now apparent from the tiny proportions of this limb bone that the early progenitors of the 'Hobbit' were even smaller than we had previously thought," Brumm said in a press release.
Reexamining the Evolutionary Path
The discovery of this bone, along with earlier finds such as a jawbone and teeth from the same site, suggests that these early humans were about 2.4 inches (6 centimeters) shorter than their later descendants.
This has reignited the debate over how Homo floresiensis evolved to such a small size and their place in the human evolutionary tree.
Researchers are still uncertain whether the hobbits shrank from an earlier, taller human species like Homo erectus, which lived in the area, or from a more primitive human ancestor.
The new findings suggest that the "Hobbit" lineage likely began when a group of early Asian hominins, possibly Homo erectus, became isolated on Flores and gradually underwent significant size reduction.
"The evolutionary history of the Flores hominins is still largely unknown," Brumm noted.
"However, the new fossils strongly suggest that the 'Hobbit' story did indeed begin when a group of early Asian hominins known as Homo erectus somehow became isolated on this remote Indonesian island, perhaps one million years ago, and underwent a dramatic body size reduction over time."
