Nine million years ago, an almost unimaginable-to-humans living situation arose in the woodlands of central Spain. There, the fossil record shows that saber-toothed cats and bear dogs were cohabitating—sharing food and living space and challenging the very stereotypes we hold about cats and dogs today.
A team of paleontologists from the University of Michigan, the Museo Nacional de Ciencias Naturales, and the University of California, Santa Cruz studied the fossilized remains of these predators, which were found in pits in central Spain. By analyzing the tooth enamel of two kinds of saber-toothed cats and bear dogs, they have created a surprisingly peaceful picture of how these creatures lived and what they ate. The team’s findings (entitled “Resource partitioning among top predators in the Miocene food web”) will be published in the latest edition of Proceedings of the Royal Society B.
The Pits and the Predators
For the past eight years, the research teach has been excavating nine sites at Cerro de los Batallones in Spain. Two of the sites are ancient pits with an abundance of meat-eating mammal bones. Agile predators, the researchers say, likely jumped into the natural traps in search of food.
“These sites offer a unique window to understand life in the past,” said Soledad Domingo, a postdoctoral fellow at the University of Michigan Museum of Paleontology and the first author of the forth-coming paper.
Inside the pits, the team found three late-Miocene Period predators: the leopard-sized saber-toothed cat Promegantereon ogygia, the much larger, lion-sized Machairodus aphanistus, and the bear dog Magericyon anceps. Neither bear nor domestic dog, bear dogs were large prehistoric predators with teeth like a dog and a body like a bear. Their physiology suggests that they moved with a lumbering gait and were capable of short bursts of speed.
Three’s Company, Too
The data suggests that the Miocene Period bear dogs and saber-toothed cats lived in a forested area that had patches of grassland. The cats likely competed for the same prey—horses and wild boar—and the smaller species would have used tree cover to avoid the larger species. The bear dogs most likely hunted antelope, which occupied more open areas. The hunting territories slightly overlapped but remained separate enough to avoid conflict.
“These three animals were sympatric—they inhabited the same geographic area at the same time. What they did to coexist was to avoid each other and partition the resources,” said Domingo.
And the Teeth Will Tell
The researchers took a special interest in the fossilized teeth they found and analyzed them to determine the creatures’ eating habits. They sampled teeth from 69 specimens, including 27 from the saber-toothed cats and bear dogs and the rest from plant eaters.
Using stable carbon isotope analysis, the team was able to determine what the creatures were eating. The data from the herbivores was used first to determine what kinds of plants were available and then to reconstruct the creatures’ environment (woodlands with some open, grassy areas). When the predators’ teeth were analyzed, the data suggested that they were all likely living in the same habitat while feeding on different sized prey.
“The three largest mammalian predators captured prey in different portions of the habitat, as do coexisting large predators today. So even though none of the species in this 9-million year old ecosystem are still alive today (some of their descendants are), we found evidence for similar ecological interactions as in modern ecosystems,” said Catherine Badgley, co-author of the new study and assistant professor of ecology and evolutionary biology.
It seems if resources are abundant and there are enough places to avoid each other, even the most traditional of enemies can find a way to live together without mass hysteria.