Liang Bua 1 was discovered by Benyamin Taurus, a hired local during the September 2003 archaeological excavations in Liang Bua cave. He was excavating a 2 by 2-meter square when he discovered the first signs of a skull [2]. LB1 was found at a depth of 5.9 m in Sector VII, with other parts of the skeleton found in Sector IV. It was initially dated to 18,000 cal. BP [1], but a revised stratigraphy and chronology of the site published in 2016, provided new dates for LB1. Directly dating the specimen gave a range of 86.9±7.9 to 71.5±4.3 kyr [1][3]. 

LB1 skeleton is extremely fragile because it has not been fossilized or covered with calcium carbonate. Recovered elements include a relatively complete cranium and mandible, right leg, and left innominate. The bones of the left leg, hands, and feet are less complete, while the vertebral column, sacrum, scapulae, clavicles, and ribs are only fragments. Tooth eruption, epiphyseal union, and tooth wear reveal that it is an adult, while the pelvic anatomy strongly indicates that it is a female [1]. 

Due to the primitive and derived features of LB1’s cranial and postcranial skeleton, Brown and colleagues proposed a new species Homo floresiensis with LB1 serving as the holotype. Although LB1 has the small endocranial volume and stature evident in early australopithecines, it does not have the great postcanine tooth size, deep and prognathic facial skeleton, and masticatory adaptations common to members of this genus. However, the facial and dental proportions, as well as the post-cranial anatomy, were consistent with human-like obligate bipedalism, and a masticatory apparatus most similar in relative size and function to modern humans, therefore they placed it under the genus Homo. They also hypothesize that the prolonged period of isolation on Flores island resulted in the evolution of an island endemic form and subsequent dwarfing [1].

This 2004 publication became controversial within the scientific community. Some researchers suggested that LB1 shows signs similar to those of Down Syndrome, which is the most common developmental disorder in humans and is also documented in related hominoids such as chimpanzees and orangutans [4]. While others believe that the LB1 is a Homo sapien that either exhibits intraspecies variation [5] or suffered from microcephaly [2].