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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.
Our favorites this week included the truth behind the term “burnout,” an incisive analysis of rap scapegoating, flowers for an aging icon, the beauty of noticing hidden wildlife, and an engaging look at history’s forgotten children. We hope you enjoy them as much as we did.
Bench Ansfield | Jewish Currents | January 3, 2023 | 3,358 words
I might have recommended this essay based on the excellent headline alone, but in fact the substance is the star of the show. Like many millennials, I have adopted the term “burnout” into my vocabulary as a way of describing the feeling of working too hard, juggling too much, and feeling depleted by the grinding expectations of late-stage capitalism. After reading this piece, I’ll be endeavoring to use the word differently. As historian Bench Ansfield shows, the true origins of burnout as a concept have been obscured over time. Burnout isn’t a reference to a candle burning at both ends until there’s nothing left, but to the shells of buildings left by a wave of arson that ravaged Black and brown neighborhoods in New York City in the ’70s. Much of the damage was caused by landlords looking for insurance payouts. “If we excavate burnout’s infrastructural unconscious — its origins in the material conditions of conflagration — we might discover a term with an unlikely potential for subversive meaning,” Ansfield writes. “An artifact of an incendiary history, burnout can vividly name the disposability of targeted populations under racial capitalism — a dynamic that, over time, has ensnared ever-wider swaths of the workforce.” If this were the premise of a college class, I’d sign up in a heartbeat. —SD
Justin A. Davis | Scalawag | February 9, 2023 | 4,089 words
Put aside the chewy headline for a moment. Also put away whatever you know or don’t know about Young Thug, one of Atlanta’s most influential rap luminaries for a decade, and the epicenter of a sprawling and questionable criminal investigation into his YSL crew. What you’ll find is a shrewd, fascinating analysis that combines a music obsessive’s encyclopedic genre knowledge and a Southerner’s geographical intimacy, refracted through a lens of accessible (a crucial modifier!) political theory. It ably unpacks the hydra-headed beast of gentrification and economics and policing, as faced by the young Black man who’s currently the Fulton County DA’s public enemy number one. “As working-class and poor Black Atlantans fight against displacement and fall back on everyday survival tactics,” Justin A. Davis writes, “they’re joining a decades-long struggle over who exactly the city’s for. So is YSL.” This sort of piece is exceedingly rare, not because of its form but because it demands an outlet that understands and nurtures its particular Venn diagram. Credit to Scalawag, and of course to Davis, for creating something this urgent. Required reading — not just for Thugga fans or Atlantans, but for anyone seeking to understand the world outside their own. —PR
Wright Thompson | ESPN | February 8, 2022 | 12,111 words
“No. 16 is no longer what it once was. Joe Montana now must be something else.” I haven’t kept up with American football in at least 20 years, but that didn’t stop me from devouring Wright Thompson’s astonishing profile of former 49er quarterback Joe Montana. I grew up watching the Niners (Ronnie Lott 4eva) and have fond memories of attending games at Candlestick as a child. But you certainly don’t need to be a Niner fan, a football fan, or even be into sports at all to appreciate this beautifully written and revealing piece. Thompson paints a portrait of a complicated man and an aging athlete — one of the greatest of all time — and what it’s like to watch someone else take over that throne. —CLR
Lucy Jones | Emergence Magazine | February 2, 2023 | 5,179 words
The forest path near us is a never-ending source of delight. I love being the first to see animal tracks in the snow. I look forward to the first yellow lady slippers that appear as if by magic near the marshy section, not to mention all the leaves and flowers as they sprout, and the myriad fungi that cling to the trees. Lucy Jones shares this wonder in nature (at slime molds in particular!) in Emergence Magazine. There she finds equal parts beauty, mystery, and wonder — a coveted yet all-too-elusive feeling nowadays — as she scans the forest for varieties that she’s just now starting to notice. “My eyes were starting to learn slime mold,” she writes. “My ways of seeing were altering, thanks to my new friends who were showing me what to look for. What was once invisible was quickly becoming apparent. It challenged my sense of perception. How little and how limited was my vision! How vast was the unknown world.”—KS
April Nowell | Aeon | February 13, 2023 | 4,400 words
April Nowell opens this piece with a delightful story about a Palaeolithic family taking their kids and dogs to a cave to do some mud painting, which feels like the modern-day equivalent of exhausted parents taking their offspring to McDonald’s and handing them a coloring book. I was instantly entranced. Such stories are rare, partly because evidence of children (with their small, fragile bones) is tricky for archaeologists to locate, but also because of assumptions that children were insignificant to the narrative. Nowell explains how, with the help of new archaeological approaches, this is changing, and the children of the Ice Age are getting a voice. I am ready to listen, so bring on these tales of family excursions and novices struggling to learn the craft of tool sculpting (as Nowell explains, “each unskilled hit would leave material traces of their futile and increasingly frustrated attempts at flake removal”). A Palaeolithic archaeologist and professor of anthropology, Nowell is an expert in this topic, but her vivid writing and human-based approach makes her fascinating field accessible to all. —CW
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While changing temperatures and rainfall had little impact on crocodiles’ gene flow over the past three million years, changes to sea levels during the Ice Age had a different effect.
“The American crocodile tolerates huge variations in temperature and rainfall. But about 20,000 years ago—when much of the world’s water was frozen, forming the vast ice sheets of the last glacial maximum—sea levels dropped by more than 100 meters [about 328 feet],” says José Avila-Cervantes, a postdoctoral fellow working under the supervision of Hans Larsson, a professor of biology at the Redpath Museum of McGill University. “This created a geographical barrier that separated the gene flow of crocodiles in Panama.”
The researchers point out that the crocodiles are good swimmers, but they can’t travel long distances on land. As a result, the Caribbean and Pacific crocodile populations were isolated from each other, and consequently have undergone different genetic mutations.
For the study in the journal Evolution, the team compared the climate tolerance of living populations of American crocodiles (Crocodylus acutus) to the paleoclimate estimates for the region over the past 3 million years—the time span of extreme climate variation during the Ice Age.
“This is one of the first times Ice Age effects have been found in a tropical species. It’s exciting to discover effects of the last Ice Age glaciation still resonate in the genomes of Pacific and Caribbean American crocodiles today,” Larsson says.
“Discovering that these animals would have easily tolerated the climate swings of the Ice Age speaks to their resilience over geological time. Only humans in recent decades of hunting and land development seem to really affect crocodiles,” he says.
The findings offer new insight into how environmental drivers affect genetic evolution and where conservation efforts of particular crocodile populations in Panama should be focused.
Source: McGill University
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