SCIENCE science.org 11 FEBRUARY 2022 • VOL 375 ISSUE 6581 623ILLUSTRATION: STEFANO MAUGERI/ROYAL SOCIETY OPEN SCIENCE/WIKIMEDIA COMMONS CC BY
By Lance GrandeO
therlands is scientific, in the sense that
the author is an award-winning young
paleontologist who uses his expertise
to reconstruct Earth’s history. But it
is by no means a textbook. Instead,
Thomas Halliday’s poetic prose posi-
tions the reader as an observer who has gone
back in time for a graphic look at 16 of Earth’s
ecosystems at different times and places,
ranging from Australia in the Ediacaran pe-
riod to Alaska in the Upper Pleistocene.
The book’s first chapter places the reader
on the northern slope of Alaska 20,000 years
ago, when the region was still connected to
Siberia. Halliday begins: “Dawn is near break-
ing in the Alaskan night, where a small herd
of horses, four adults and three foals, huddle
against the frigid northeasterly wind. By this
time, the sun has been gone for well over ten
hours, and the air is skin-tighteningly cold.”
The text continues in this vein, weaving in
descriptions of other creatures living along
the mammoth steppe and the forests of the
Bering land bridge.
“To the roaming horses of the North Slope,
and to the cave lions that pursue them, the
steppe must seem immovably wide, but when
seen at the scale of deep time, permanence is
an illusion,” writes Halliday, at the chapter’s
end. “As the ice retreats, all it takes is a drop
of rain, and the hard land beneath the stamp-
ing hooves will soon give way. All it takes is
a flicker, and the aurora dies.” Such passages
bring this long-extinct ecosystem to life.
In chapter 2, Halliday moves to Kanapoi,
Kenya, 4 million years ago, vividly highlight-
ing the sensory experiences of early homi-
nids: “A scream of alarm from a turaco sets a
commotion among a troop of Australopithe-
cus. Disturbed from chewing on leaves, the
hominins scramble to their feet and run to
climb lianas to safety....”Halliday’s next stop is Gargano, Italy, and
the Zanclean flood, which occurred 5.33
million years ago. Gargano, we learn, was
once an island known for highly endemic
fauna, some of which showed signs of gi-
gantism and dwarfism: think enormous
geese and tiny deer-like ruminants. Eventu-
ally, however, Gargano “found itself below
the waves, its unique creatures wiped out.”
In Tinguiririca, Chile, 32 mil-
lion years ago, Halliday paints a
portrait of the first grasslands to
evolve on the planet and a few of
the animals that took advantage of
them. On Seymour Island, Antarc-
tica, some 41 million years ago, we
observe a climate that was much
warmer than it is currently with a
much more diverse biota. “Exactly
when and where the Antarctic bi-
ota died out on Antarctica itself is
not known,” writes Halliday. “Unlike the early
doomed human expeditions to the Antarctic
interior, there is no diary, no record of the
dates and places of species death.”
In chapter 6, Halliday examines the post-
Cretaceous biosphere after the Chicxulub
asteroid impact, which resulted in the extinc-
tion of most terrestrial species. The burning
fires and explosive debris obscured the sky
so deeply that “after two years of darkness,
two years without photosynthesis anywhere
worldwide, two years of rain infused withnitric and sulfuric acid entering the oceans,
populations have failed...For three quarters
of species on Earth, every male, every female,
every adult and every child is dead. It is the
winter that lasts a generation.”
Other places and times covered in the
book include Swabia, Germany, 155 million
years ago; Madygen, Kyrgyzstan, 225 million
years ago; Moradi, Niger, 253 million years
ago; Rhynie, Scotland, 407 million
years ago; Yaman-Kasy, Russia,
435 million years ago; Chengji-
ang, China, 520 million years ago;
and the Ediacara Hills of Austra-
lia, 550 million years ago.
“The world as it is today is a
direct result—not a conclusion or
a denouement, but a result—of
what has gone before,” concludes
Halliday. By the same logic, what
we do (or do not do) today can
mold our future in profound ways. Halliday
states that “this is now undoubtedly a human
planet.” However, I might emphasize that it
is not the planet that is in peril right now, it’s
us. Species come and go over time, but the
planet remains.
Overall, this book is a highly entertaining
read for anyone who wishes to be transported
back to various points in Earth’s history. It
is also a novel approach to igniting broader
public interest in the field of paleobiology. j
10.1126/science.abn5448PALEONTOLOGYVivid snapshots
of the past
A paleontologist offers an
immersive look at pivotal
moments in Earth’s history
The reviewer is at the Negaunee Integrative
Research Center, Field Museum, Chicago, IL 60605, USA.
Email: [email protected]BOOKS et al.
The enormous flightless Garganornis ballmanni lived in what is now Gargano, Italy, during the late Miocene.Otherlands
Thomas Halliday
Random House, 2022.
416 pp.