Location | Gauteng Province, South Africa |
---|---|
Coordinates | 26°02′00″S27°42′43″E / 26.033235°S 27.712057°E |
Part of | Cradle of Humankind |
Area | 1.3 km2 (0.50 sq mi) |
History | |
Periods | Early Pliocene, Plio-Pleistocene, Late Pleistocene, Holocene |
Bolt's Farm is a palaeontological site in the Cradle of Humankind World Heritage Site, Gauteng province, South Africa. With more than 30 fossil deposits dating back 4.5 Ma, it is one of the oldest sites currently discovered in the Cradle of Humankind. It consists of multiple cavities, pits, and quarries, where caves have eroded away, exposing their fossiliferous interiors. Although this site has not yet yielded the hominid fossils for which the Cradle of Humankind is known, Bolt's Farm is still an important source of fossils from various species of Early Pliocene and Plio-Pleistocene fauna, including primates and big cats.
Bolt's Farm is located about 3 km (1.9 mi) southwest of the Sterkfontein archaeological site and is located in the southwestern corner of the Cradle of Humankind World Heritage Site. The site is carved out of the Malmani Subgroup of the Transvaal Supergroup, which formed during the Palaeoproterozoic era around 2.6–2.4 billion years ago under what was then an inland sea. [1]
The pockmarked appearance of the area is the result of heavy ancient cave erosion down to the floors and walls of the passages, resulting in dozens of dolomite solution cavities and palaeokarst pits that have preserved fossils in breccia, speleothem, sandstone, and siltstone. These deposits occur over a 1.3 km2 (0.50 sq mi) stretch of hillside. [1] [2] [3] It is unknown if these caves were once interconnected and contemporary with one another, or if they existed separately. The oldest of these deposits yet known is Waypoint 160, which was discovered in 1996 and has been dated back to the Early Pliocene, approximately 4.5–4 Ma. [4] [2] Almost all other sites have been dated back only to the Plio-Pleistocene; dates vary from one pit to the next, although most fall in the range of 2–1 Ma. One site, New Cave, may hold fossils that are significantly more recent; remains there have been dated to the Late Pleistocene into the Holocene. [5]
Palaeontological studies of the fossils recovered at the site seem to suggest that, at the time the site was active, the region was drier and the area was more open than it is today. [6] The species recovered from Bolt's Farm and the greater Sterkfontein Valley area may have inhabited a range of local habitat types, ranging from covered forest to open grasslands. Browser and grazer species, as well as ground and tree-dwelling primates, are represented in the fossil record. [7] [4] At least one location on the site dated to 2–1.5 Ma, Pit 23, has been theorised to have been a "death trap" where ancient fauna inadvertently fell to their deaths and their remains were preserved over time. [5]
The area on the northern edge of a farm owned by Billy Bolt, for whom the site is named, was first used as a speleothem quarry during the late 19th and early 20th centuries. Miners harvested this speleothem for use in lime production. This process unearthed fossil deposits, which were first sampled and examined by palaeontologist Robert Broom during a 1936 expedition to Transvaal. Broom named many of the fossil taxa recovered from the site. [8] In 1947 and 1948, a team of researchers from the University of California Museum of Paleontology (UCMP) led by palaeontologists Frank Peabody and Charles Lewis Camp, called the University of California Africa Expedition, began exploring palaeontological sites across eastern and southern Africa. A team of the southern branch of the expedition led by Peabody was responsible for the first excavation at Bolt's Farm. [5] The mining had created rubble chunks containing fossiliferous breccia; early investigations retrieved material from this rubble, instead of mining it in situ . Additionally, the UCMP excavations were centred on the main quarry. Multiple smaller excavations have been completed in the decades since. Historically, Bolt's Farm has been ignored for sites where hominid fossils have already been discovered, which are of much more interest to archaeologists; thus, the study of the site has lagged behind that of its neighbors like Sterkfontein. [1] [2]
Until the 1990s, the precise locations of multiple fossiliferous pits within the larger site were poorly recorded and thus unable to be located by subsequent archaeologists. Renewed surveying began in the 1990s has attempted to rediscover the deposits first described in—but barely explored since—the 1940s. In the process, these surveys have unsurprisingly uncovered new sites. In 1991, Basil Cooke published the first updated map of the site since the 1940s excavations; however, attempts to line up Peabody's original map and site descriptions with sites identified in more recent surveys remain a source of confusion for researchers. [8] However, Cooke's survey marked the beginning of a period of renewed interest in Bolt's Farm. A survey done by French researchers from 1996 to 1999 revealed new fossil species and sites, including Waypoint 160, which is thought to be the oldest known site in the Cradle of Humankind. [1] [2] A survey done by the Cradle of Humankind's Human Origins and Past Environments Research Unit (HRU) team between 2008 and 2011 identified 23 old sites and eight new ones. [3] Further surveys carried out in the late 2010s have used GIS and aerial drone surveying to more accurately identify these sites. [8]
Some of the specimens collected during the 1940s excavations have been lost; however, many of those surviving are stored at the University of California Museum of Paleontology at the University of California, Berkeley. Beginning in the late 1950s, loans and repatriation efforts have handed over many of the fossils to the Evolutionary Studies Institute at the University of the Witwatersrand in Johannesburg. [9] The Ditsong National Museum of Natural History in Pretoria is also in possession of Bolt's Farm specimens, where many are kept on semi-permanent display to the public. [10]
Fossils recovered from the Bolt's Farm pits represent a wide array of macrofauna. Animals active in the Bolt's Farm area during the Plio-Pleistocene included big cats, non-hominid primates, snakes, horses, mustelids, bovids, pigs, antelope, rodents, jackals, reptiles, and birds of prey. Signs of various microfauna have also been uncovered but not studied in-depth. [2]
The deposits have also yielded some of the oldest primate fossils in the Cradle of Humankind; they belong to Parapapio (specifically, Pp. broomi and Pp. whitei), extinct species of baboons that have also been located at Sterkfontein, Taung, and Makapansgat. The Pp. whitei specimens from Bolt's Farm are the most complete remains of this species that have been discovered. [11] [6] Other primate remains include Theropithecus , Papio robinsoni and Cercopithecoides williamsi . [12] [13] Because hominid fossils contemporary to the depositional period have been recovered in similar conditions in east African archaeological sites, several researchers have put forth the suggestion that hominid fossils could be found at Bolt's Farm as well. [1]
Other species represented in the Bolt's Farm fossil deposits are Antidorcas recki , Ictonyx bolti , Metridiochoerus andrewsi , [14] Euryotomys bolti , Elephantulus antiquus , [15] Boltimys broomi , [9] and Proteles cristatus . [16] Bolt's Farm has yielded some of the best specimens of Plio-Pleistocene big cats in South Africa, including a complete skull and jaw of the saber-toothed cat Dinofelis barlowi . [12] The first fossil remains of a snake belonging to the family Elapidae recovered from southern Africa were collected from Bolt's Farm in 2009. [17] The 2016 discovery at Bolt's Farm of the first fossil Agama lizard recovered from the Cradle of Humankind was announced in 2020. [18]
The Ditsong National Museum of Natural History, formerly the Transvaal Museum, is a natural history museum situated in Pretoria, South Africa. It is located on Paul Kruger Street, between Visagie and Minnaar Streets, opposite the Pretoria City Hall. The museum was established in 1895 by the former South African Republic, also known as the Transvaal. In 2010 it was one of the founding museums of Ditsong Museums of South Africa.
The Cradle of Humankind is a paleoanthropological site that is located about 50 km (31 mi) northwest of Johannesburg, South Africa, in the Gauteng province. Declared a World Heritage Site by UNESCO in 1999, the site is home to the largest known concentration of human ancestral remains anywhere in the world. The site currently occupies 47,000 hectares (180 sq mi) and contains a complex system of limestone caves. The registered name of the site in the list of World Heritage Sites is Fossil Hominid Sites of South Africa.
Sterkfontein is a set of limestone caves of special interest in paleoanthropology located in Gauteng province, about 40 kilometres (25 mi) northwest of Johannesburg, South Africa in the Muldersdrift area close to the town of Krugersdorp. The archaeological sites of Swartkrans and Kromdraai are in the same area. Sterkfontein is a South African National Heritage Site and was also declared a World Heritage Site in 2000. The area in which it is situated is known as the Cradle of Humankind. The Sterkfontein Caves are also home to numerous wild African species including Belonogaster petiolata, a wasp species of which there is a large nesting presence.
Mrs. Ples is the popular nickname for the most complete skull of an Australopithecus africanus ever found in South Africa. Many Australopithecus fossils have been found near Sterkfontein, about 40 kilometres (25 mi) northwest of Johannesburg, in a region of Gauteng now designated as the Cradle of Humankind World Heritage Site. Mrs. Ples was discovered by Robert Broom and John T. Robinson on April 18, 1947. Because of Broom's use of dynamite and pickaxe while excavating, Mrs. Ples's skull was blown into pieces and some fragments are missing. Nonetheless, Mrs./Mr. Ples is one of the most "perfect" pre-human skulls ever found. The skull is currently held at the Ditsong National Museum of Natural History in Pretoria.
Australopithecus africanus is an extinct species of australopithecine which lived between about 3.3 and 2.1 million years ago in the Late Pliocene to Early Pleistocene of South Africa. The species has been recovered from Taung, Sterkfontein, Makapansgat, and Gladysvale. The first specimen, the Taung child, was described by anatomist Raymond Dart in 1924, and was the first early hominin found. However, its closer relations to humans than to other apes would not become widely accepted until the middle of the century because most had believed humans evolved outside of Africa. It is unclear how A. africanus relates to other hominins, being variously placed as ancestral to Homo and Paranthropus, to just Paranthropus, or to just P. robustus. The specimen "Little Foot" is the most completely preserved early hominin, with 90% of the skeleton intact, and the oldest South African australopith. However, it is controversially suggested that it and similar specimens be split off into "A. prometheus".
Swartkrans is a fossil-bearing cave designated as a South African National Heritage Site, located about 32 km (20 mi) from Johannesburg. It is located in the Cradle of Humankind World Heritage Site and is notable for being extremely rich in archaeological material, particularly hominin remains. Fossils discovered in the limestone of Swartkrans include Homo ergaster, Paranthropus and Homo habilis. The oldest deposits present at the site are believed to be between 1.9 and 2.1 million years old.
The Evolutionary Studies Institute (ESI) is a paleontological, paleoanthropological and archeological research institute operated through the Faculty of Science of the University of the Witwatersrand, Johannesburg, South Africa. Previously known as the Bernard Price Institute for Palaeontological Research (BPI) it was renamed the Evolutionary Studies Institute in 2013 to better showcase the scope of its research.
Kromdraai Conservancy is a protected conservation park located to the south-west of Gauteng province in north-east South Africa. It is in the Muldersdrift area not far from Krugersdorp.
Charles Kimberlin Brain, also known as C. K. "Bob" Brain, was a South African paleontologist who studied and taught African cave taphonomy for more than fifty years.
Cooper's Cave is a series of fossil-bearing breccia filled cavities. The cave is located almost exactly between the well known South African hominid-bearing sites of Sterkfontein and Kromdraai and about 40 kilometres (25 mi) northwest of Johannesburg, South Africa and has been declared a South African National Heritage Site.
Gladysvale Cave is a fossil-bearing breccia filled cave located about 13 kilometres (8.1 mi) northeast of the well-known South African hominid-bearing sites of Sterkfontein and Swartkrans and about 45 kilometres (28 mi) north-northwest of Johannesburg, South Africa. It is situated within the Cradle of Humankind World Heritage Site and is itself a South African National Heritage Site.
Motsetsi Cave is a fossil-bearing breccia filled cavity located about 14 kilometres (8.7 mi) east of the well known South African hominid-bearing sites of Sterkfontein and Kromdraai and about 45 kilometres (28 mi) north-northwest of Johannesburg, South Africa. Motsetsi has been declared a South African National Heritage Site.
Plovers Lake Cave is a fossil-bearing breccia-filled cavity in South Africa. The cave is located about 4 km southeast of the well-known South African hominid-bearing sites of Sterkfontein and Kromdraai and about 36 km northwest of Johannesburg. Plovers Lake has been declared a South African National Heritage Site.
Kromdraai is a fossil-bearing breccia-filled cave located about 2 kilometres (1.2 mi) east of the well-known South African hominid-bearing site of Sterkfontein and about 45 kilometres (28 mi) northwest of Johannesburg, South Africa. It is situated within the Cradle of Humankind World Heritage Site and is itself a South African National Heritage Site.
Dinopithecus is an extinct genus of very large primates, closely related to baboons, that lived during the Pliocene and Pleistocene epochs in South Africa and Ethiopia. It was named by British paleontologist Robert Broom in 1937. The only species currently recognized is Dinopithecus ingens, as D. quadratirostris has been reassigned to the genus Soromandrillus. It is known from several infilled cave sites in South Africa, all of early Pleistocene age, including Skurweberg, Swartkrans, and Sterkfontein.
Malapa is a fossil-bearing cave located about 15 kilometres (9.3 mi) northeast of the well known South African hominid-bearing sites of Sterkfontein and Swartkrans and about 45 kilometres (28 mi) north-northwest of Johannesburg, South Africa. It is situated within the Cradle of Humankind World Heritage Site.
Gondolin Cave is a fossiliferous dolomitic paleocave system in the Northwest Province, South Africa. The paleocave formed in the Eccles Formation dolomites. Gondolin is currently the only described hominin-bearing fossil site in the Northwest Province-portion of the designated Cradle of Humankind UNESCO World Heritage Site. The cave is located on privately owned land and is not accessible to the public. As is the case with other South African Paleo-cave systems with Pliocene and/or Pleistocene fossil deposits, the system was mined for lime during the early 20th century. As a result, the system has been heavily disturbed and consists of only a small active cave, a series of in situ remnant cave deposits, and extensive dumpsites of ex situ calcified sediments produced during mining activities.
André Werner Keyser, was a South African palaeontologist and geologist noted for his discovery of the Drimolen hominid site and of numerous hominid remains.
Haasgat is a fossiliferous South African paleocave located in the Cradle of Humankind UNESCO World Heritage Area, approx. 20 kilometres (12 mi) northeast of the hominin-bearing sites of Sterkfontein and Swartkrans and approx. 60 kilometres (37 mi) north-northwest of the City of Johannesburg. It is located on private land and is not accessible by the public.
Minnaar's Cave, or simply Minnaar, is a palaeontological site located in the Cradle of Humankind World Heritage Site, Gauteng province, South Africa. Lost after its discovery in the 1930s, its location was rediscovered in 2009. It is known for its well-preserved jackal skulls, dating to the Plio-Pleistocene at least 2 million years ago.