The Ohio University's paleontologists have found a new species of meat-eating mammal that is larger than any big cat stalking the world today. The large carnivore which is larger than a polar bear with a skull as large as that of a rhinoceros and enormous piercing canine teeth would have been a threatening aspect of the eastern African ecosystems taken by early apes and monkeys.
The researchers published the new study in the Journal of Vertebrate Paleontology and gave the species the name by Simbakubwa kutokaafrika, a large carnivore known as most of its jaw, parts of its skull, and portions of its skeleton. Decades ago, researchers unearthed the 22-million-year-old fossils in Kenya while canvassing the region searching for evidence of ancient apes. They placed the specimens in a drawer at the National Museum of Kenya and did not give it a great deal of attention until Dr. Nancy Stevens and Dr. Mathew Borths from Ohio University rediscovered them and recognized their significance.
The lead author of the study, Borths, said that when opening a museum drawer, they saw a row of gigantic meat-eating teeth, clearly belonging to a species new to science. While conducting the research, Borths was a National Science Foundation Postdoctoral Research Fellow with Stevens in the Department of Biomedical Sciences at Ohio University. Now, Borths is the Curator of the Division of Fossil Primates at the Duke Lemur Center at Duke University.
The meaning of Simbakubwa in Swahili is 'big lion' since the animal was likely at the top of the food chain in Africa, as lions are in modern African ecosystems. Still, Simbakubwa was not closely related to big cats or any other mammalian carnivore alive today. In its place, the animal fit in with a vanished set of mammals called hyaenodonts.
The first mammalian carnivores in Africa were the hyaenodonts. For about 45 million years following the disappearance of the non-avian dinosaurs, hyaenodonts were the apex predators in Africa. Then, after near-isolation for millions of years, movements of tectonic of the Earth's plates connected Africa with the northern continents, allowing flora and faunal exchange between landmasses. During the time of Simbakubwa, the relatives of hyenas, cats, and dogs began to arrive in Africa from Eurasia.
With the relatives of cats and dogs moving towards south, the Simbakubwa's relatives took to the north. Borths said that it is a fascinating time in biological history. Lineages that have no encounter of one another began to appear together in the fossil record.
Professor in the Heritage College of Osteopathic Medicine at Ohio University, Stevens said that this is a pivotal fossil, demonstrating the significance of museum collections for understanding evolutionary history. He added further that Simbakubwa is a window into a bygone era. With the shifting of ecosystems, a key predator disappeared, heralding the transition of Cenozoic fauna that eventually led to the evolution of the modern Africa fauna.
