36 | New Scientist | 1 August 2020
A
BOUT 250 million years ago,
a creature raced along the edge
of a lake in what is now Poland,
leaving prints behind it in the mud. It
was a meek and forgettable animal called
Prorotodactylus, about the size of a pet cat
and with slender limbs. But those prints
weren’t the only legacy it left: its descendants
somehow became the rulers of Earth.
Those descendants were the dinosaurs.
The very word invokes majesty. These
were among the most successful groups of
animals ever, dominating the planet for more
than 100 million years. They proliferated into
creatures of all shapes and sizes, some even
larger than a jet plane, and filled the land.
Palaeontologists like me were long
obsessed with understanding why these
mighty animals were snuffed out 66 million
years ago. We now know the answer: their
days were ended by an enormous asteroidimpact. Today, the greatest mystery of
dinosaur evolution is how they rose to
glory in the first place.
The early descendants of Prorotodactylus
would have stuck to the shadows, skulking
away from much larger and more fearsome
animals. So what was it that allowed them
to take centre stage? Piecing together
the answer is no easy matter. But over the
past few years, a surprising new idea has
gained traction. Perhaps the reason for the
dinosaurs’ ascendency lies not in their teeth
or claws or muscles. It may instead be thanks
to a series of strange anatomical adaptations
invisible from the outside – adaptations
that allowed them to thrive in one of the
most extreme periods of climate change
the planet has seen up until now.
The world was almost unrecognisable back
when Prorotodactylus made those lakeside
prints. Our planet had just experienced one RONALD
KURNIAWANFeatures
The unlikely
rise of the
dinosaurs
Dinosaurs started off as pipsqueaks in a world of
heavyweight competitors. How they ascended to
glory is a mystery we’re only just starting to unravel,
says palaeontologist Steve Brusatte