Australian-Geographic-Magazine-September-Octobe..

S–O 2014 71

Shaped something like a fat dolphin, this 7m-long air breather

is highly adapted to life in the oceans. She has massive saucer-

shaped eyes that allow her to pick up traces of light in the depths

where she hunts for squid; she also gives birth to live young in

the water, so she does not need to venture onto land to lay eggs

as turtles and crocodiles do.

Hunting deep-sea squid is not the only similarity she has

with modern sperm whales. Like them, she is also a uniform jet

black, which helps camouflage her in the inky depths and absorb

as much warmth from the sun as possible when she comes to

the surface for air. Normally she spends as little time near the

surface as she can, because this is where she is most vulnerable

to larger predators.

Today, though, she is lingering, because she is about to give

birth. This Platypterygius is among the last of her kind. Ichthyo-

saurs have been enormously successful for 150 million years, but

they have been on the decline for tens of millions of years and

now they face a new threat in the form of larger marine rep-

tiles known as mosasaurs. Little does she know it in her current

agitated state, but a 15m-long mosasaur has been circling in the

waters beneath her for some time now. Part of a group that will

give rise to monitor lizards and snakes, mosasaurs have elongated

bodies, four flippers and long tails with broad flukes on the end.

This predator is darkly pigmented on its upper side and lightly

pigmented on its underside, making it di„cult to spot from

both above and below. Before the Platypterygius has the chance

to give birth, the mosasaur shoots up from the depths, violently

clamping her within its wide jaws and bringing nearer to an end

the long tenure of ichthyosaurs in these prehistoric waterways.

This scenario is fanciful, but, thanks to a study published

in January 2014 by researchers led by Johan Lindgren at Lund

University in Sweden, we now have some good clues as to the

colour of both ichthyosaurs and mosasaurs. The research was

the first to reveal the colour of extinct marine creatures and it

followed on from a string of recent papers that has revealed the

colours of prehistoric birds and feathered dinosaurs by mapping

pigment-bearing structures within fossilised skin and feathers.

“This is fantastic!” Johan told reporters. “When I started

studying at Lund University in 1993, the film Jurassic Park had

just been released... Then, it was unthinkable that we would ever

find biological remains from animals that have been extinct for

many millions of years, but now we are there and I am proud

to be a part of it.”

N

INETY-FOUR MILLION years ago, a vast inland sea runs the

length of North America from the Arctic Ocean to the Gulf

of Mexico. Its waters are an effective barrier that divides the

landmasses of Laramidia to the west and Appalachia to the east,

and both are home to a diverse and unique fauna of early birds

and feathered carnivorous dinosaurs. Predatory reptiles stalk the

waterways too, and among their number is a lone ichthyosaur of

a kind known as Platypterygius.

Ocean-going hues.

In 2014 scientists at

Lund University in

Sweden used high-

powered microscopes

to determine the

true colours of a

prehistoric turtle, an

ichthyosaur (centre)

and a mosasaur.

The latter two are

both giant marine

reptiles that were

contemporaries of

the dinosaurs.

OPPO

SIT

E: BR

IAN CHOO;

Microraptor

sp.;

TH

IS PAGE: LU

ND UNI

VER

SIT

Y / S

TEFAN SØ

LBERG

ag0914p071_dinos - 71 2014-08-12T11:44:12+10:00