Outing to Bolt’s Farm in the Cradle of Humankind
By: 
Guided by Dr Nonny Vilakazi
Date: 
Wed, 17/04/2024 - 09:00
Branch: 
Northern
Outing to Bolt’s Farm in the Cradle of Humankind
Guided by Dr Nonny Vilakazi

Date: Wednesday, 17 April 2024 
Time: 09h00 for 09h30 
Parking: Meet at the parking at Greensleeves. 
Charge: members R50, non-members: R150.

Bolt's Farm is a fauna-bearing area with distinct loci that is part of the UNESCO Cradle of Humankind World Heritage Site.  It is known to have produced some big felids, including the nearly whole skull found at Pit 23 that is connected to Dinofelis barlowi's jaw. Additionally, it has produced a rather significant collection of non-hominid primates, including the well-preserved skull of Cercopithecoides williamsi (BF 42) and the peculiar skull of Parapapio (BF 43). Additionally, Waypoint 160 (the oldest known fossil deposit in the Cradle of Humankind through biochronology) is found in Bolt’s Farm. In the past few years, the team has found several new and significant fossils, including an upper molar of Mylomygale sp. at BPA, a few teeth of a Tetraconodontinae (Gerontochoerus koobiforaensis) at BPB, and a fragmentary skull of a bald ibis (Geronticus calvus) at BPB now G. thackerayi. The finding of Gerontochoerus koobiforaensis teeth indicates a connection to East Africa. Other taxa most likely travelled between East and Southern Africa; one such taxon could be hominids. This is one illustration of how biodiversity changed in South Africa during the Plio-Pleistocene.
 
Dr. Nonny Vilakazi is a Palaeontologist at UJ (focusing on palaeo-herpetology) and a co-permit holder of Bolt’s Farm Karstic System. She deems the significance of the fossil reptiles lies in their ability to provide valuable insights into the ecosystem's evolution and changes over time. Reptiles are recognized to be bio-indicators, meaning they can reveal information about the palaeoenvironment because of their high sensitivity to temperature.
 
Link to the parking lot at Greensleeves, where we’ll park.
https://maps.app.goo.gl/axvAXK7ziZfFhbsN7?g_st=iw
 
Bolt’s Farm is about 2.5 kms south-west of Sterkfontein Caves. 
There will be walking of about 20 minutes to the first site so wear comfortable walking shoes, a hat, bring sunblock and drinking water. 
There is unfortunately no suitable place for a picnic lunch, but participants may book for lunch if they so wish at Greensleeves, at their own cost. 

Please take note of the following important information about booking and payment:
BOOKING CONDITIONS FOR OUTINGS
Contact Anne Raeburn to book, preferably by email: anner@mweb.co.za or if email not available then by phone: 072 349 6507.
Do not pay until you have confirmed your booking with Anne.
If you pay before your booking is confirmed and an outing is already fully booked, we must refund your payment. This entails a lot of extra work.
Please deposit the fee in the BRANCH account given below (and NOT in the Cape Town membership account). SA Archaeological Society, Standard Bank, Account number 001 945 920 Reference: SURNAME and EVENT. Send the deposit slip to Anne Raeburn e-mail anner@mweb.co.za or cell: 072 349 6507. If you pay by cash or cheque, you must please add R40 for bank fees. 

PROTOCOL FOR OUTINGS:
Please take note of the following guidelines for outings: 
1. Arrive on time and immediately report to the committee member who has the attendance register. 2. Sign the attendance register and indemnity form. 
3. Only people who have booked and pre-paid may come on outings, we do not accept bookings or cash on the day. 
4. Stay with the group. We do our best to stick to time schedules.
Since the group will be limited to 25 visitors it is advisable to book promptly if you wish to participate in this outing.

Report back on Outing to Bolts Farm, Cradle of Humankind on 17 April 2024

Attendees being met by Dr Nonny Vilakazi at Bolt’s Farm

On Wednesday 17 April 2024, twenty members of the Northern Branch joined a fascinating outing to an excavation site on Bolt’s Farm.  This fossil site is named after Mr Billy Bolt, the owner of the original farm that sat on the eastern Greensleeves property and Sterkfontein Quarry.
Bolt’s Farm is a Plio-Pleistocene fossil site located within the southwestern corner of the UNESCO Hominid Fossil Sites of South Africa World Heritage Site. The site is a complex of active caves and more than 20 palaeokarst deposits or pits, many of which were exposed through the action of lime mining in the late 19th and early 20th century. The lime was used in the extraction of gold process. Karst is a type of landscape where the dissolving bedrock has created sinkholes, cave, springs and other similar features. Karst is associated with soluble rock types such as limestone. To date no hominin remains have been found at Bolt’s Farm.
 
Robert Broom collected the first fossils from Bolt’s Farm in 1936 and during 1947-48, the University of California’s African Expedition surveyed and sampled several locations on the property.
In the 1980’s Ugo Ripamonti collected fossil material and during 1996-99 the French Palaeontology Expedition to South Africa (PESA) also collected specimens. During 2001, the Ditsong Museum collaborated with French Institutions to establish the Human Origins and Past Environments program (HOPE) and excavations have continued here intermittently, ever since. 
It is now generally accepted that the site consists of deposits of various ages that formed either as part of the same cave system at different times or may represent the infill of several completely unconnected caves.
Although Bolt’s Farm contains more than 30 sites, we only visited one site, namely the Pliocene Aves Cave Complex currently being excavated by Dr Dominique Gommery, from Centre National de Recherché Scientifique and Sorbonne University in France, in conjunction with the Ditsong Museum, Pretoria. 
Dr. Nonny Vilakazi, a Palaeontologist at UJ, focusing on palaeo-herpetology, guided us to the site towards the top of a hill from the parking site. She is a co-permit holder of the Bolt’s Farm karstic system, where the significance of the fossil reptiles relates to their ability to provide valuable insights into the ecosystem's evolution and changes over time.  
 
On our meander to the site, Dr Vilakazi informed us that we would be informed about microfauna and fossil finds, including a snake fang. Reptiles are recognized to be bio-indicators because they can reveal information about the palaeoenvironment because of their high sensitivity to temperature.

Peering into the excavation pit at the Ava Cave Complex while being briefed by Drs Gommery and Vilakazi

At the Aves Cave Complex, Dr Vilakazi introduced us to Dr Gommery and Lazarus Kgasi from the Ditsong Museum, Pretoria. This site, where both have excavated for several years, appears to be a collapsed limestone cave. 
Dr Gommery briefed us on the excavations and discoveries at the Bolt’s Farm.  Important finds have been some felid Dinofelids, including the nearly whole skull found at Pit 23 that is connected to Dinofelis barlowi's jaw. A significant collection of non-hominid primates has been found, including the well-preserved skull of Cercopithecoides williamsi (BF 42) and the peculiar skull of Parapapio (BF 43). Faunal material from one of the sites named Waypoint 160, suggests that the site is one of the oldest Plio-Pleistocene sites in the area, possibly as old as 4.5 Ma. 

The excavation team has found several new and significant fossils, including an upper molar of Mylomygale sp. at BPA, a few teeth of a Tetraconodontinae (Gerontochoerus koobiforaensis) at BPB, and a fragmentary skull of a bald ibis (Geronticus calvus) at BPB now G. thackerayi. The finding of Gerontochoerus koobiforaensis teeth indicates a connection to East Africa. Other taxa most likely travelled between East and Southern Africa; one such taxon could be hominids. This is one indication of how biodiversity changed in South Africa during the Plio-Pleistocene (5.3 Ma – 11 700 BCE). Taxonomy is the branch of biology that classifies all living things into groups of organisms called taxa. 
The excavation of the site has uncovered coral and layers of different soil and rocks. It has also shown evidence of changes in the environment, weather and climate. Here, dolomite, sediment, gravel and fine sediment with microfauna have been recorded.
Bone material of eight individual Cave Lions, some of adults and others of cubs have been excavated. Similarly, bone material of leopards, Black and White rhinos were found. The fossilized remains of pigs, related to bushpigs, and linked to those found in Tanzania have also been located here. Ibis, both new and extinct species have been excavated. Fossilized molars were pointed out to us near the entrance to the collapsed cave. The Evolutionary Studies Institute at Wits University and Ditsong National Museum of Natural History, Pretoria, are repositories for some Bolt’s Farm specimens. Afterwards, most of the attendees retired to the Bidon Bistro in the Cradle of Humankind, to enjoy a cappuccino and a chat about the interesting outing we had just completed.

Thank you to Dr Nonny Vilakazi for taking us to this site.
 
Report by Hilary Geber and photos by SJ de Klerk