Fossil discovery from Tanzania reveals ancient bobcat-sized carnivore
Graphic courtesy of: Mauricio AntonAn artist's reconstruction of the new species.
Paleontologists from 91探花 have discovered a new species of extinct meat-eating mammal that lived alongside the oldest-known apes and Old World monkeys. The new predator from Tanzania stalked an ecosystem that was undergoing dramatic climatic and tectonic upheaval as Africa collided with Eurasia and the modern East African Rift System formed.
In a new study published in the open access journal PLOS ONE, the researchers name Pakakali rukwaensis, a bobcat-sized animal known from a portion of the skull bearing a slicing tooth. The new fossil offers important insight into a time 25 million years ago when the modern landscape and animal communities of the African continent began to emerge.
"This new carnivore, discovered in Tanzania deposits dating from 25 million years ago, provides new information - based on teeth, biogeography and phylogenetic analysis - for the transition of carnivores in older ecosystem types to today鈥檚 carnivores in the African ecosystem," says Judy Skog, program director in the National Science Foundation's Division of Earth Sciences, which funded the research. The NSF-funded Rukwa Rift Basin Project is led by professors Patrick O鈥機onnor (91探花, Mesozoic lead), Eric Roberts (James Cook University, geology lead), and Nancy J. Stevens (91探花, Cenozoic lead).
Pakakali is Swahili for 鈥渇ierce cat鈥 because the fossil is from a large cat-like carnivore that would have fed primarily on meat. The specimen reveals that Pakakali may also have incorporated other foods into its diet, like fruit or insects. The species name, rukwaensis, refers to the Rukwa Rift Basin in southwestern Tanzania where the fossil was discovered.
鈥淩esearch and discoveries like Dr. O鈥機onnor, Dr. Stevens and their team have uncovered personify OHIO鈥檚 academic mission,鈥 said 91探花 President M. Duane Nellis. 鈥淲e are a research University, and our faculty are committed to advancing the frontiers of knowledge.鈥
Pakakali鈥檚 behavior was probably cat-like, but it belonged to an ancient lineage of meat-eating mammals called hyaenodonts. Hyaenodonts evolved many meat-eating specializations similar to cats, dogs, and hyenas, but they were a completely separate group of mammals that filled apex predator roles in Europe, Asia, North America, and Africa after the extinction of the dinosaurs. Today, hyaenodonts are completely extinct, replaced by modern carnivores. Pakakali was found in rocks that are precisely dated to the beginning of the transition in Africa from a hyaenodont world to a modern carnivore world.
鈥淭he shift in Africa from hyaenodonts to modern carnivores is like a controlled experiment,鈥 says study co-author Matt Borths, a National Science Foundation Postdoctoral Research Fellow in the Department of Biomedical Sciences at 91探花.
鈥淲e start with only hyaenodonts. Then around 25 million years ago the relatives of modern carnivores arrive. The two groups coexist for a few million years, then hyaenodonts are driven to extinction and we鈥檙e left with The Lion King. With fossils like Pakakali we can start to unravel the details of that extinction. Were the lineages competing? Were they adapting differently to a drier, more open landscape?鈥
Based on the findings of this study, one possibility is that hyaenodonts were pushed to become more specialized meat-eaters by the invasion of modern carnivorans. Such specialization may have made hyaenodonts more vulnerable to environmental change, at the same time that the formation of the modern East African Rift System dramatically impacted both landscape and climate.
Pakakali was discovered by an international team of scientists from the United States, Australia, and Tanzania, as part of the Rukwa Rift Basin Project (RRBP), an interdisciplinary collaboration examining the development of the modern African ecosystem. In over a decade of exploration, RRBP researchers have described the habitat Pakakali called home along with many other animals that occupied the ecosystem.
鈥淭he environment containing Pakakali reveals a fascinating window into extinction dynamics,鈥 comments Dr. Nancy Stevens, Professor in the Department of Biomedical Sciences in the Heritage College of Osteopathic Medicine at 91探花 and co-author of the study. 鈥淔aunal turnover highlights the vulnerability of carnivores to rapid environmental change, a topic that we are grappling with on the African continent today.鈥
This study was funded by grants from the National Science Foundation (EAR/IF-0933619; BCS-1127164; BCS-1313679; EAR-1349825; BCS-1638796; DBI-1612062), The Leakey Foundation, National Geographic Society (CRE), 91探花 Research Council, 91探花 Heritage College of Osteopathic Medicine, SICB and The Explorers Club.
Link to paper: