A former Wits student, Dr Juan Cisneros, has discovered and named a fossil in Brazil which has close links to a species which was discovered at Williston in the Northern Cape in 1999 by a team of workers from the Bernard Price Institute for Palaeontology at the University of the Witwatersrand.
Cisneros and two Brazilian colleagues, together with Prof Bruce Rubidge, director of the Bernard Price Institute for Palaeontological Research (BPI) at Wits and Dr Fernando Abdala, also from the BPI, has co-authored a paper published in Science on Friday, 25 March 2011 on the new species.
The new find, together with the specimen from Williston, is the oldest evidence of similar faunas of land-living vertebrates between the African and South American continents, thus demonstrating that more than 260-million years ago these animals were moving between what are today the continents of Africa and South America.
The new Brazilian animal is remarkable as it has long sabre canines reflecting the oldest evidence of combat behaviour in a herbivorous “reptile”, and is also the oldest record of dental occlusion in the evolutionary lineage leading toward mammals.
The paper, entitled "Dental occlusion in a 260-million-year-old therapsid with saber canines from the Permian of Brazil" presents Tiarajudens eccentricus, a 260-million year old herbivorous basal anomodont from Brazil which has its closest relative in Anomocephalus africanus, a species found in South Africa a decade ago. The two species form a new group, previously unrecognised, that lived in Brazil and South Africa (then Gondwana) more than 260-million years ago.
“This provides additional evidence of geographic contact between terrestrial faunas from these now separate continents; but, more importantly, it also establishes a temporal bridge, in other words, the faunas having these animals represent nearly similar ages on both continents,” says Prof Rubidge.
Abdala explains: “The new Brazilian species presents some unexpected dental features: it is the oldest known herbivore that shows sabre canines. This indicates that they used this large tooth for display against predators and also intraspecifically. The new species also shows a battery of teeth following the canine that are placed in bones from the palate, ectopterygoid and pterygoid, and show evidence of dental occlusion with teeth from the lower jaw.”