Fossil WLH-50 is a partial

cranium The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

that was discovered in 1982, in the Willandra Lakes Region of Australia and was reconstructed by Alan Thorne. Speculation surrounds the exact age of this fossil

hominid The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the east ...

and a debate concerning its

ancestry An ancestor, also known as a forefather, fore-elder or a forebear, is a parent or (recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, great-great-grandparent and so forth). ''Ancestor'' is "any person from whom ...

in relation to other

late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of ...

hominids, as well as,

Ngandong Solo Man (''Homo erectus soloensis'') is a subspecies of ''H. erectus'' that lived along the Solo River in Java, Indonesia, about 117,000 to 108,000 years ago in the Late Pleistocene. This population is the last known record of the species. I ...

hominids due to their close resemblance to one another.

Characteristics

It has been said that WLH-50 has many of the same features as ''

Homo erectus ''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor' ...

'', but some of WLH-50's most notable characteristics include: * Thick Brow ridge * Unusually thick, dense cranial vault – 15–19 millimetres thick (supposed adaptation to

Malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

) * Cranial Capacity – 1590cc * Extended

Nuchal The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering of the Arabic , "spinal marrow"). The corresponding adjective is ''nuchal'', as in the term ''nu ...

Area for muscle attachment *

Occipital bun The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cereb ...

* Robust size

Determining age

The fossil was discovered in a lake basin that undergoes several drying phases throughout the year. These phases cause displacements in the surrounding sediment and stratigraphy, thus making it difficult to properly date the fossil. There have been many attempts in trying to accurately date WLH-50 some of which include:

Radio carbon dating

In 1981 and 1982 the

Australian National University The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and ...

radio carbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was dev ...

lab tested the

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

that encrusted the bone, as well as a freshwater shell and found: * Carbonate – 9050 ± 310 BP (calibrated to 9.5–11.1 thousand years old, 2-σ error) * Freshwater shell – 14,380 ± 240 BP (calibrated to 16.5–18.0 thousand years old)

Electromagnetic spin resonance

In 1987 D.A. Caddie conducted ESR dating technique and calculated that the bone fragment was 29,000 ± 5,000 years old.

Spectrometry

Simpson and Grun reported in 1998 that the fossil was potentially 14,000 years old, according to

gamma spectroscopy Gamma-ray spectroscopy is the quantitative study of the energy spectra of gamma-ray sources, such as in the nuclear industry, geochemical investigation, and astrophysics. Most radioactive sources produce gamma rays, which are of various energie ...

and thermal ionization mass spectrometry (TIMS)/ Uranium-series dating. It has been suggested that the latter technique provides a minimum age for this fossil, due to the fact that uranium uptake begins following burial.

Replacement Theory vs. Multi-Regional Mode

An ongoing debate within

paleoanthropology Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship ...

is whether to place Ngandong hominids as ''Homo sapiens''. Replacement theory predicts that Late Pleistocene Africans and Levantines are direct ancestors of WHL-50 and that Ngandong hominids are not direct ancestors of WHL-50. The Multi-regional model considers Pleistocene Africans, Levantines, and Ngandong possible ancestors to WHL-50, making Ngandong a ''H. sapiens''.

References

{{Reflist Prehistoric mammals of Australia Hominin fossils