We’ve prob­a­bly all heard of the Sterk­fontein Caves, and pos­si­bly even of Krom­draai and Cooper’s Cave, locat­ed in the Cra­dle of Humankind.

Cat Big 1

Mod­el of a sabre-toothed cat, Sterk­fontein Caves exhi­bi­tion. Pho­to cour­tesy Flow­comm

These are famous fos­sil sites where exca­va­tions con­tin­ue to bring the most amaz­ing dis­cov­er­ies to the sur­face to help us piece togeth­er our pre­his­toric past.

But there is anoth­er excit­ing, less pub­licly known loca­tion where a wealth of ani­mal fos­sils, par­tic­u­lar­ly those of big cats, has been unearthed. These are thought to be between about 2.9-million and 4.5-million years old.

Bolt’s Farm is 2.5km south-west of the Sterk­fontein Caves. The rock here is dolomite and lime­stone, in which there is a series of quarries.

Fos­sils of ante­lope, pigs, ele­phants and rodents have been found there, but Bolt’s Farm is nick­named the King­dom of the Big Cats” because of the dis­cov­ery of many big cat (felid) and sabre-toothed cat (Dinofe­lis) spec­i­mens.

Sci­en­tif­ic significance 

Bolt’s Farm is huge­ly sig­nif­i­cant as it is the first place in Africa where the par­tial skele­tons of big cats have been found.

One of its sites, called Way­point 160, has been pegged at about 4.5-million years in age, based on rodent fos­sils found in the cal­ci­fied brec­cia (sed­i­men­ta­ry rock). This means it could be the old­est site in the Cra­dle of Humankind. 

What makes [Bolt’s Farm] so spe­cial is that it pro­vides a cross-sec­tion of time for much of the Plio-Pleis­tocene, approx­i­mate­ly 5-mil­lion years of change,” explains the col­lec­tion man­ag­er at Dit­song Nation­al Muse­um of Nat­ur­al His­to­ry, Stephany Potze.

Research at Bolt’s Farm has also con­clud­ed that many more species of pre­his­toric car­ni­vores exist­ed than was pre­vi­ous­ly thought.

A glance back at history

Cradle Of Humankind Fossil Sabre Tooth Closeup

The fos­silised tooth of a sabre-toothed cat embed­ded in brec­cia. Pho­to: Tara Turkington

The first fos­sils on Bolt’s Farm were dis­cov­ered 75 years ago by Pro­fes­sor Robert Broom, who pio­neered palaeoan­thro­pol­o­gy in South Africa.

Then, in 194748, an exca­va­tion spear­head­ed by the Uni­ver­si­ty of Cal­i­for­nia dis­cov­ered three, well pre­served Dinofe­lis skele­tons in what they called Pit 23”. 

These sabre-toothed cats lived between 5-mil­lion and 1.4-million years ago.

The male, female and a young­ster were found togeth­er with the remains of baboons and it was hypoth­e­sised that the baboons were chased by the cats, fell into the pit, fol­lowed by the fam­i­ly of felines. 

It appears that not much reg­u­lar sci­en­tif­ic work was done on Bolt’s Farm until a South African/​French col­lab­o­ra­tion in 1995. It result­ed in the launch of the Human Ori­gins and Past Envi­ron­ments (Hope) Research Unit at the for­mer Trans­vaal Muse­um, Pre­to­ria, now called the Dit­song Nation­al Muse­um of Nat­ur­al History.

In 2001, the research unit came across what the sci­en­tists called the Femur Dump” on Bolt’s Farm. It is like­ly that this is the Pit 23 dis­cov­ered by the expe­di­tion of 194748.

Pri­mate and felid remains like those exca­vat­ed from Pit 23 were dis­cov­ered, but also some new finds like hyaenids (car­rion-eat­ing car­ni­vores like hye­nas) and tortoises.

Potze says the research unit is cur­rent­ly exca­vat­ing more than 20 dif­fer­ent ani­mal fos­sil deposits of var­i­ous ages on Bolt’s Farm. So it’s not like the Sterk­fontein Caves, which is just one site – it’s what we call a karstic net­work.” (“Karstic” means a land­scape that has been shaped by water eat­ing into sol­u­ble rock over time.)

The work at Bolt’s Farm has been fund­ed by the French Embassy in Pre­to­ria, the Cen­tre Nation­al de la Recher­ché Sci­en­tifique in Paris, South Africa’s Nation­al Research Foun­da­tion and Dit­song Muse­ums of South Africa.

Com­mem­o­rat­ing Pro­fes­sor Robert Broom

Fos­sils from Bolt’s Farm will be exhib­it­ed at Maropeng by the Dit­song Nation­al Muse­um of Nat­ur­al His­to­ry. This exhi­bi­tion coin­cides with the Broom Col­lo­qui­um on Novem­ber 262011.

Maropeng, in part­ner­ship with the Roy­al Soci­ety of South Africa, is host­ing this event to hon­our Broom and com­mem­o­rate the 60th anniver­sary of his death.

Potze says vis­i­tors will be able to see a range of fos­sils from pri­mates, car­ni­vores and rodents to suids (pigs). These fos­sils span the long peri­od of exca­va­tion at Bolt’s Farm from 1936 when Broom first con­duct­ed work there, to cur­rent exca­va­tions by the Hope Research Unit .

Lead­ing sci­en­tists involved in recent palaeon­to­log­i­cal dis­cov­er­ies will also be pre­sent­ing on var­i­ous research issues.

The Broom Col­lo­qui­um is open to the pub­lic and tick­ets are avail­able online. The cost is R300 inclu­sive of tea, lunch and entry to all the pre­sen­ta­tions and the exhibition. 

Book online for the Broom Col­lo­qui­um