Paleontologists have unearthed the 5.2-million-year-old fossilized remains of four sabertooth cat species — including two previously unknown species, name Lokotunjailurus chinsamyae and Dinofelis werdelini — at Langebaanweg ‘E’ Quarry in South Africa. Their results suggest that the distribution of sabertooths throughout ancient Africa might have been different than previously assumed.
The sabertooth cat species Lokotunjailurus emageritus and the gomphothere-like elephantid species Stegotetrabelodon in Late Miocene Lothagam, Kenya. Image credit: Mauricio Antón / CC BY 3.0.
“The known material of sabertooths from Langebaanweg was relatively poor, and the importance of these sabertooth cats has not been properly recognized,” said Complutense University paleontologist Alberto Valenciano.
“Our phylogenetic analysis is the first one to take Langebaanweg species into consideration.”
Dinofelis sabertooths are globally distributed, and their fossils have been found in Africa, China, Europe, and North America.
Dr. Valenciano and his colleagues were expecting to identify a new Dinofelis species from Langebaanweg based on prior research.
However, Lokotunjailurus sabertooths have only ever been identified in Kenya and Chad before this new study.
This suggests that they may have been distributed all throughout Africa between 5-7 million years ago.
To construct a family tree, the authors classified the physical traits of each sabertooth species — such as presence or absence of teeth, jaw and skull shape, and tooth structure — and coded this information into a matrix that could determine how closely related each sabertooth was to its evolutionary cousins.
The resulting population composition of Langebaanweg sabertooths (Machairodontini, Metailurini, and Feline) reflects the increasing global temperatures and environmental changes of the Pliocene epoch.
For instance, the presence of Machairodontini cats, which are larger in size and more adapted to running at high speeds, suggests that there were open grassland environments at Langebaanweg.
However, the presence of the Metailurini cats suggests that there were also more covered environments, such as forests.
While the fact that researchers found both Metailurine and Machairodonti species suggests that Langebaanweg contained a mixture of forest and grassland 5.2 million years ago, the high proportion of Machairodonti species compared with other fossil localities from Eurasia and Africa confirm that southern Africa was transitioning toward more open grasslands during this period.
Langebaanweg ‘E’ Quarry represents one of the largest and best-preserved collections of sabertooth felids from Mio-Pliocene deposits of Africa. Image credit: Jiangzuo et al., doi: 10.1016/j.isci.2023.107212.
“The continuous aridification throughout the Mio-Pliocene, with the spread of open environments, could be an important trigger on the bipedalism of hominids,” the paleontologists said.
“The sabertooth guild in Langebaanweg and its environmental and paleobiogeographic implications provide background for future discussion on hominid origination and evolution.”
Interestingly, the composition of sabertooths in Langebaanweg closely mirrors that of Yuanmou, China.
Yuanmou’s Longchuansmilus sabertooths might even have a close evolutionary relationship with Africa’s Lokotunjailurus species.
“This suggests that the ancient environment of the two regions was similar or that there was a potential migration route between the Langebaanweg and Yuanmou,” said Peking University paleontologist Qigao Jiangzuo.
“The two new sabertooths are only an example of the numerous unpublished fossils from Langebaanweg housed at Iziko in the Cenozoic Collections,” said Dr. Romala Govender, a curator and paleontologist at the Iziko Museums.
“This brings to the fore the need for new and detailed studies of Langebaanweg fauna.”
A paper on the findings was published in the journal iScience.
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Qigao Jiangzuo et al. Langebaanweg’s sabertooth guild reveals an African Pliocene evolutionary hotspot for sabertooths (Carnivora; Felidae). iScience, published online July 20, 2023; doi: 10.1016/j.isci.2023.107212
