The Bullock Creek Fossil site is one of three known

vertebrate Vertebrates () comprise all animal taxon, taxa within the subphylum Vertebrata () (chordates with vertebral column, backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of 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 ...

sites in the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Au ...

of Australia, along with the

Alcoota Fossil Beds __NOTOC__ The Alcoota Fossil Beds are an important paleontological Lagerstätte in the Northern Territory of Australia located on Alcoota Station in the locality of Anmatjere about north-east of Alice Springs in the Central Australia regi ...

and the

Kangaroo Well Kangaroos are four marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern gre ...

site on Deep Well Station. It is located about south-southeast of

Darwin Darwin may refer to: Common meanings * Charles Darwin (1809–1882), English naturalist and writer, best known as the originator of the theory of biological evolution by natural selection * Darwin, Northern Territory, a territorial capital city i ...

, on Camfield Station in the locality of Victoria River. The Bullock Creek Fossil Site is part of the

Camfield Fossil Beds Camfield is a surname. Notable people with the surname include: *Anne Camfield (1808–1896), Australian photographer, pioneer teacher and headmistress *Bill Camfield (1929–1991), American television personality * Douglas Camfield (1931–1984), ...

which outcrop in a narrow belt about 50 km long. The Bullock Creek local fauna are approximately dated to the mid

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

(about 12 million years ago). The Camfield Fossil Beds which contain the Bullock Creek local fauna consist of light coloured calcareous

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

and

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

. Ferruginous mottling is found at the base and chalcedonic silification at the top. The presentation of fossils at the site ranges from poorly sorted fragmentary lags to associations with partial skeletons which includes complete crania (skulls) with intact delicate structures. The Bullock Creek Fossil Site is of natural significance in providing evidence for the evolution of the Northern Territory's fauna and climate. The Bullock Creek Fossil site is part of the Camfield Fossil Beds which are one of only a few Australian localities where rare fossil marsupials are well preserved. Among the fossils at the Bullock Creek site have been found complete marsupial crania with delicate structures intact. New significant taxa identified from the Bullock Creek mid Miocene include a new genus of crocodile, '' Baru'' (''Baru darrowi''), a primitive true kangaroo, ''

Nambaroo ''Nambaroo'' is an extinct genus of macropod marsupial from the late Oligocene to the early Miocene of Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of ...

'', with high-crowned lophodont teeth; and a new species of giant horned tortoise, '' Meiolania''. New marsupial lion,

thylacine The thylacine ( , or , also ) (''Thylacinus cynocephalus'') is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The last known live animal was captured in 1930 in Tas ...

, and

dasyurid The Dasyuridae are a family of marsupials native to Australia and New Guinea, including 71 extant species divided into 17 genera. Many are small and mouse-like or shrew-like, giving some of them the name marsupial mice or marsupial shrews, but t ...

material has also been recovered. The extensive collection of '' Neohelos'' (large browsing marsupial) remains from the Camfield beds has initiated a review of the mid Miocene zygomaturine diprotodontids. Together with the fossil assemblage in the Alcoota Fossil Beds to the north-east of Alice Springs, the Bullock Creek fossil fauna demonstrates systematic and community structural continuity from the mid to late Miocene in northern Australia. The Bullock Creek assemblage contains biological evidence of seasonality (trapping of small fish in drying backwaters), while lithostratigraphic evidence (interbedded evaporites) suggests longer periods of low precipitation and probably high ambient temperatures. The assemblage provides evidence that

aridification Aridification is the process of a region becoming increasingly arid, or dry. It refers to long term change, rather than seasonal variation. It is often measured as the reduction of average soil moisture content. It can be caused by reduced precip ...

was in progress in northern Australia during the Miocene. The fossil site was listed on the

Northern Territory Heritage Register The Northern Territory Heritage Register is a heritage register, being a statutory list of places in the Northern Territory of Australia that are protected by the Northern Territory statute, the ''Heritage Act 2011''. The register is maintained b ...

on 3 August 1996 under the name "Bullock Creek Fossil Site."

References

Further reading