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The recent discovery of a sabertooth cat skull in southwest Iowa is the first evidence the prehistoric predator once inhabited the state.
The chance of finding any fossilized remains from a sabertooth cat is slim, says Matthew Hill, an associate professor of archaeology at Iowa State and expert on animal bones. The remarkably well-preserved skull found in Page County is even rarer, and its discovery offers clues about the iconic Ice Age species before its extinction roughly 12-13,000 years ago.
“The skull is a really big deal,” says Hill. “Finds of this animal are widely scattered and usually represented by an isolated tooth or bone. This skull from the East Nishnabotna River is in near perfect condition. It’s exquisite.”
Hill analyzed the specimen in collaboration with David Easterla, professor emeritus of biology at Northwest Missouri State University. Their findings appear in the journal Quaternary Science Reviews.
The researchers used radiocarbon dating to determine the cat died at the end of the Ice Age between 13,605 and 13,460 years ago. Hill says it may have been one of the last sabertooths to walk the planet as glaciers receded and temperatures rose.
“We think southwest Iowa during this period was a parkland with patches of trees interspersed with grassy openings, somewhat similar to central Canada today,” says Hill. “The cat would have lived alongside other extinct animals like dire wolf, giant short-faced bear, long-nosed peccary, flat-headed peccary, stag-moose, muskox, and giant ground sloth, and maybe a few bison and mammoth.”
Hill and Easterla believe the skull belonged to a subadult (2-3 year old) male when it died. Gaps between the skull’s boney plates indicate its head was still growing, and the permanent teeth don’t show much wear from cutting and chewing. To figure out its sex, they compared its skull measurements with adult male and female sabertooth skulls from the Rancho La Brea tar pits in Los Angeles.
Hill explains sabertooth were sexually dimorphic, meaning males were larger than females. Since the Iowa skull is larger than many male skulls from the tar pits, the researchers argue it belonged to a male. They estimate the Iowa cat weighed about 550 pounds at death and may have approached 650 pounds as an adult in prime physical condition. In comparison, the average adult male African lion weighs about 400 pounds.
How the sabertooth cat died is not clear. But a broken canine might offer a clue. Hill and Easterla speculate the animal was seriously injured while attacking prey, which ultimately proved fatal within days of the trauma.
Small patches of worn-down bone on top of the skull indicate it slid along a river-bottom before coming to rest and then buried for thousands of years.
“We can learn a lot from these types of fossils. They hold clues about the ecology of the animals, and how they respond to dramatic climate change and the appearance of a new predator and competitor on the landscape, including people,” says Hill. “Iowa is a fantastic laboratory to do research on extinct Ice Age animals and the people who were just beginning to share the landscape with them.”
Research opportunities with the sabertooth cat skull don’t end with the published analysis, the researchers say.
Hill suspects the cat’s primary prey was Jefferson’s giant ground sloth, which were common in Iowa during the Ice Age. They’d sit beside trees and bushes and pull in leaves and buds to eat. At 8-to-10 feet tall and over 2,200 pounds, giant ground sloths were massive. Hill believes only a large predator armed with “absolutely lethal jaws and claws” and legs designed for pouncing could hunt them regularly.
To test this, Hill is teaming up with Andrew Somerville, assistant professor of archaeology at Iowa State who is an expert in dietary reconstruction using bone geochemistry. Together, they’re developing a stable isotope mixing model with samples from the sabertooth cat, other carnivores, and herbivores (e.g., Jefferson’s ground sloth, muskox, stag-moose.)
“You are what you eat, and it’s locked in your bones,” says Hill.
Stable isotopes make it possible for researchers to know what plants herbivores eat and, in turn, what herbivores carnivores eat. They can piece together local food webs and how species filled ecological niches.
“So, maybe the sabertooth was primarily eating giant ground sloth, dire wolves, primarily moose, and short-faced bears, a little bit of everything. Andrew and I are going to figure it out,” says Hill.
The researchers expect to publish their findings in the coming year.
Source: Iowa State University
The post ‘Near-perfect’ sabertooth cat skull is first sign they lived in Iowa appeared first on Futurity.
A new fossil discovery reveals complex ecosystems existed on Earth much earlier than previously thought.
The discovery challenges understanding of how quickly life recovered from the greatest mass extinction in Earth’s history.
About 250 million years ago, the Permian-Triassic mass extinction killed over 80% of the planet’s species. In the aftermath, scientists believe that life on Earth was dominated by simple species for up to 10 million years before more complex ecosystems could evolve.
Until now, scientists have long theorized that scorching hot ocean conditions resulting from catastrophic climate change prevented the development of complex life after the mass extinction. This idea is based on geochemical evidence of ocean conditions at the time. Now the discovery of fossils dating back 250.8 million years near the Guizhou region of China suggests that complex ecosystems were present on Earth just one million years after the Permian-Triassic mass extinction, which is much earlier than previously thought.
“The fossils of the Guizhou region reveal an ocean ecosystem with diverse species making up a complex food chain that includes plant life, boney fish, ray-finned fish, crabs, lobsters, shrimp, and mollusks. In all, our team discovered 12 classes of organisms and even found fossilized feces, revealing clues about the diets of these ancient animals,” says Morgann Perrot, a former postdoctoral researcher at McGill University, now at Université du Québec à Montréal.
Previously, it was thought that complex ecosystems would need five to 10 million years to evolve after an extinction. However, the researchers found that the specimens in the Guizhou region evolved much quicker than that by using radiometric dating to date the rocks where the fossils were discovered.
“All of this has implications for our understanding of how quickly life can respond to extreme crises. It also necessitates a re-evaluation of early Triassic ocean conditions,” says Perrot, whose research focuses on earth sciences and geochronology.
The research appears in Science.
Source: McGill University
The post Earth had complex ecosystems earlier than thought appeared first on Futurity.
Enlarge / The Nicobar pigeon, the dodo's closest living relative, is quite a bit smaller and capable of flight. (credit: Samuel Hambly / EyeEm)
Colossal is a company that got its start with a splashy announcement about plans to do something that many scientists consider impossible with current technology, all in the service of creating a product with no clear market potential: the woolly mammoth. Since that time, the company has settled into a potentially viable business model and set its sights on a species where the biology is far more favorable: the thylacine, a marsupial predator that went extinct in the early 1900s.
Today, the company is announcing a third de-extinction target and its return to the realm of awkward reproductive biology that will force the project to clear many technical hurdles: It hopes to bring back the dodo.
The dodo was a large (up to 1 meter tall), flightless bird that evolved on the island of Mauritius in the Indian Ocean. As European sailors reached the islands, it quickly became a source of food for them and the invasive species that accompanied them. It went extinct within a century of the first descriptions reaching Europe.
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