HOW DO WE
KNOW WHAT
DINOSAURS
LOOKED LIKE?
YOU’VE SEEN ENOUGH MUSEUM
models, illustrations, and CGI pred-
ators that you’d likely recognize a
Tyrannosaurus rex if you saw one. But
how can you be sure? Nobody has
ever clapped eyes on one in real life,
and even the best skeletons are often
only 90 percent complete. Special-
ists called paleo artists do base their
re- creations on hard evidence (bones,
feathers, and bits of skin) but, just
as often, well- informed guesses. We
may never know exactly how T. r e x
and other prehistoric creatures like
the Micro raptor gui looked, but here’s
how we landed on the current incar-
nations of these deceased beasts.
MUSCLE AND FAT
Like reptiles, dinosaurs probably
didn’t have much body fat, so
they looked pretty swole. To de-
termine just how stocky or svelte
to render a species, paleontol-
ogists most often refer to the
same muscle groups in birds. But
sometimes there’s an evolution-
ary reason to make an area extra
burly: A T. r e x, for example, had
to kill prey and bite through bone
with only its jaw strength—hence
its thick-neckedness.STANCE
The way joints fit together in-
forms a dino’s pose—along with a
bit of inspiration from contempo-
rary creatures. Without cartilage
and other connective tissues,
experts map extinct skeletons
against how birds and reptiles
stand and walk. Using those
methods, they inferred that T. r e x
held its spine horizontally, which
means the tail shot straight back
rather than dragging as it was
depicted prior to the ’70s.
HEAD
Tyrannosaurs’ smooth, toothy
skulls are quite reptilian. But un-
like crocs or gators, dinosaurs
were terrestrial, so they may have
needed to trap moisture inside
their mouths to stay hydrated.
That’s why many depictions have
partial lips, more akin to lizards.
Studying eye sockets tells art-
ists how to orient the peepers.
Frontward- angled holes, such as
those on the Microraptor, would
have pointed the eyeballs ahead.BY SARA CHODOSH
ILLUSTRATION BY THALES MOLINA
68 SPRING 2020 / POPSCI.COM