105 hominid

The 105 hominid is an unnamed genus or species of robust australopithecine that lived in South Africa during the Early Pleistocene.

## History

Keneiloe Molopyane, curator, and a team of others unconvered a fossilferous site at the Cradle of Humankind in August 2020 and would come to be called UW 105. Lee Berger, lead of the expedition, announced that the process would be documented online in real time. After intensive mapping, on-site labs were set up for preparation of hominin fossils, the first being a mandible and many more soon to be systematically excavated. Of these include the tooth crown of a "new hominid", with Berger anticipating many more finds. In September 2020, the first postcrania were reported, a single rib. The original mandible was micro CT scanned, suggesting a younger age than originally thought. Additional facial elements, such as a maxilla, were then found. Blocks at UW 105 are very abundant, with most containing many hominin fragments, such as an upper incisor. In November of the same year, Berger began to search in waste piles created by miners who had occupied the site, finding a canine and other faunal remains. Overall, the known remains includes various teeth, mandibles, facial and neurocranial elements, foot and hand bones, ribs, a radius, an ulna, tibiae, a fibula, a clavicle and a humerus. As of April 2021, 4 individuals of overlapping material were known. These individuals were discovered in separate blocks and somewhat associated

## Description

The teeth display extreme cases of megadontia, nearly 2x as large as *Praeanthropus afarensis*. The original mandible has an unerupted M3 and an erupted M2, suggesting an age of 15-16 years or 19-20 years. One tooth belongs to an individual in their mid 20s. The postcrania are surprisingly gracile, more so than *P. afarensis*, and their association with the crania being justified due to their proximity. This makes it one of the smallest-bodied hominins ever discovered. A deciduous, worn canine and many fragments may belong to an infant individual.

## Classification

   The large molar GDA-2 from Gondolin has been assigned to *Paranthropus* sp., with some suggesting *P. robustus*, which would greatly expand the morphological and size range. However, Grine et al. (2012) suggested that it fits well within *P. boisei*, which was penecontemporaneous., but suggest it is a *P. robustus* based on cusp proportions, probability of two robust australopiths in one environment and the possibility that it may be a large male and thus the species' postcanine megadontia is underestimated. With the contribution of the UW 105 site, Berger suggested comparison with this molar to the new hominids based on size, concluding that they are likely the same species.

## Paleobiology

What may be a bone tool was spotted by expeditioners in early December, 2020. Another tool, a modified antelope horn, was discovered, displaying wear near the pointed tip. This fossil was likely scavenged from the surface, since it also bears teeth puncture marks created by a carnivorous animal. It may have been used to dig up roots.

## References

* https://wakelet.com/wake/a9fnRzKiRLAXF\_xZF8tOp
* https://www.youtube.com/watch?v=9nE2xbavD5U&ab\_channel=TheFossilVault
* https://twitter.com/Evo\_Explorer/status/1302655996154740738
* https://pubmed.ncbi.nlm.nih.gov/22901553/