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IN ASSOCIATION WITHWorld’s
largest
turtle shell
discovered
Words by Laura GeggelA
n 8-million-year-old turtle shell
unearthed in Venezuela measures
nearly 2.4 metres long, making it
the largest complete turtle shell known to
science, a recent study reported.
This shell belonged to an extinct beast
called Stupendemys geographicus which
lived in northern South America during
the Miocene epoch, which lasted from 12
million to 5 million years ago.
S. geographicus weighed an estimated
1,145 kilograms, almost 100 times the size
of its closest living relative, the Amazon
river turtle (Peltocephalus dumerilianus),
and twice the size of the largest living
turtle, the marine leatherback sea turtle
(Dermochelys coriacea).
Its impressive shell makes this ancient
creature “one of the largest, if not the
largest turtle that ever existed,” said study
senior researcher Marcelo Sánchez-
Villagra, the director of the
Paleontological Institute and Museum at
the University of Zurich. The species likely
achieved its colossal size thanks to the
warm wetlands and lakes in its habitat,
Sánchez noted.Antarctica
loses huge
amounts of ice
in record heat
Words by Brandon SpecktorI
t’s easy to forget that Antarctica is technically
a desert until you see it without snow, but a
new pair of satellite images shared by NASA’s
Earth Obser vator y makes that stark realit y as
clear as ice.
NASA’s Landsat-8 satellite snapped the t wo
images of Eagle Island, a small island off
A ntarctica’s northwestern tip, on 4 and 13
February 2020, bookending a period of record-
high temperatures in the southernmost
continent. Bet ween the t wo images a significant
amount of the island’s glacial ice disappeared,
revealing huge swaths of the barren brown
rock underneath.
According to glaciologist Mauri Pelto, a
professor of environmental science at Nichols
College in Massachusetts, the island lost about
20 per cent of its seasonal snow accumulation in
just a few days.
"You see these kinds of melt events in A laska
and Greenland, but not usually in A ntarctica,"
Pelto explained.
The melt coincided with not just one, but two
record-high temperatures recorded on
Antarctica this month. On 6 February a researchstation on the northern edge of the A ntarctic
Peninsula – the finger of land on the continent’s
northwest tip, closest to South A merica –
recorded a new record-high temperature of
18.3 degrees Celsius – surpassing the prev ious
record of 17.5 degrees Celsius that was set in
March 2015.
Days later on 9 Februar y, researchers on the
nearby Seymour Island saw their thermometers
hit 20.75 degrees Celsius, setting another all-time
high for the continent.
As the new images show, those high
temperatures caused significant melting on
nearby glaciers. According to Pelto, Eagle Island
lost nearly 1.5 square kilometres of snowpack to
the heat, creating several large ponds of
bright-blue meltwater at the island’s centre.
While ever y season has its highs, this summer
has been especially warm for A ntarctica, Pelto
said. The continent has already seen t wo
heatwaves this season – one in November 2019
and one in Januar y 2020 – reminding us that
significant melt events like these are becoming
much more common as global warming
continues unchecked.Antarctica’s Eagle Island between
4 and 13 February 2020Venezuelan palaeontologist Rodolfo
Sánchez and a male carapace of
Stupendemys geographicus© Edwin Cadena
PLANET EARTH
HISTORY
© NASA Earth Observatory