Namibia fossil is a prehistoric 'swamp thing' with menacing fangs
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[July 05, 2024]
By Will Dunham
(Reuters) - You might call it the "swamp thing." About 280 million years
ago, a large creature built somewhat like a salamander but with
frightful fangs prowled the swamps and lakes of what is now Namibia,
ambushing prey as a top predator in a chilly ecosystem long before the
dinosaurs.
The creature, named Gaiasia jennyae, lived during the Permian Period and
measured at least 8 feet (2.5 meters) long - and perhaps up to 13 feet
(4 meters), according to researchers who announced the discovery of its
fossilized remains. Its large, round, flat skull measured more than 2
feet (60 cm) long, and it had interlocking fangs at the front of its
mouth.
"Wide flat heads in modern animals usually are used to generate strong
suction to ambush prey by suddenly sucking it into their mouths. Gaiasia
combines that with huge fangs for grabbing and killing large prey," said
Jason Pardo, a postdoctoral fellow in paleontology at the Field Museum
in Chicago and one of the leaders of the research published this week in
the journal Nature.
The fossils were unearthed in Namibia, a country in southwest Africa.
Because of the gradual movement over time of the crustal plates that
form Earth's outer layer - a process called plate tectonics - this place
was even further south when Gaiasia lived, almost even with Antarctica's
current northernmost point. The bodies of water it inhabited may have
sat alongside patches of ice and glaciers.
"In the far south, where Gaiasia lived, an ice age was ending, and it
was still quite cold, with large glaciers at even low altitudes," Pardo
said.
Roughly 100 million years before Gaiasia existed, the first land
vertebrates had evolved from fish with fleshy fins. These are called the
stem tetrapods. They lived an amphibious lifestyle though were not true
amphibians. The term tetrapod, meaning "four feet," refers to all land
vertebrates. The earliest ones, the stem tetrapods, spawned evolutionary
lineages that led to true amphibians, reptiles and mammals.
While this was taking place, some stem tetrapods persisted, especially
in remote places like Namibia was at the time. Gaiasia was one of these.
"Most of what we know of terrestrial life at this time comes from the
ancient equator, preserved in rocks from Europe and North America. From
that, we had thought early tetrapods were trapped in the tropics by
their physiology," Pardo said, until they disappeared amid competition
from newly evolved competitors.
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An artist’s rendering of the Permian Period salamander-like creature
Gaiasia jennyae, whose fossils were found in Namibia, is seen in
this handout image obtained by Reuters on July 3, 2024. Gabriel Lio/Handout
via REUTERS
"Gaiasia shows clearly that this is not correct. Stem tetrapods were
thriving at high latitudes in very cold environments, and those
ecosystems were dominated by some very unexpectedly primitive
animals. That forces us to rethink a lot about early tetrapod
evolution," Pardo said.
So Gaiasia was a stubborn holdover.
"Gaiasia is very different from anything else we've seen, so it
could be a lone survivor, but it could also be part of a vibrant
ecosystem of similarly strange animals that were no longer important
parts of the ecosystem in the tropics," Pardo said.
Evolution was moving in leaps and bounds during the Permian.
"At this time we see a flurry of evolution in the forerunners of
mammals, such as Dimetrodon, an animal the size of a mountain lion
that looked something like a big lizard with a giant sail on its
back and was the top predator in most of these ecosystems. We also
see forerunners of reptiles diversifying in interesting ways that
mirror modern lizards, and the first true amphibians," Pardo said.
The Permian ended about 252 million years ago with Earth's worst
mass extinction. The first dinosaurs appeared roughly 230 million
years ago during the Triassic Period.
The creature's name Gaiasia refers to the Gai-as rock formation in
Namibia where it was found, and jennyae honors the late British
paleontologist Jenny Clack, who studied early tetrapods. But how
about a catchy nickname for it?
"'Swamp thing' is excellent," Pardo said.
(Reporting by Will Dunham in Washington; Editing by Daniel Wallis)
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