JOHN YANG: Now to our
"NewsHour" Shares, something
interesting that caught our eye.

Ray Stanford has been looking
for dinosaurs in creek beds
and rivers for more than 30

years.

Despite being a self-taught
tracker, Stanford is
something of a legend
among paleontologists.

As the "NewsHour"'s Pamela
Kirkland reports, six years ago,
he made his biggest discovery

to date.

RAY STANFORD, Paleontologist:
There's part of a track down
to the lower right, too.

PAMELA KIRKLAND: When it
comes to tracking dinosaurs,
Ray Stanford is a natural.

Stanford is a self-taught
paleontologist known
for his talent for
finding dinosaur fossils

from the Cretaceous era,
140 to 65 million years ago.

In 2010, while visiting his
wife, Sheila, an information
specialist at NASA's Goddard

Space Flight Center, he
noticed a loose rock.

RAY STANFORD: This is the
theropod track that led to
ultimately the grand discovery.

PAMELA KIRKLAND: On a separate
visit two years later, a rock
on the hillside, not far from

the first track he
found, caught his eye.

RAY STANFORD: If you had
told me this, I would
never have believed
that I was going to find

something like this.

PAMELA KIRKLAND: This time, it
was the footprint of a nodosaur,
the Cretaceous period's version

of an armadillo.

Beneath the ground,
there were more tracks
Stanford couldn't see.

After years of analysis, it
turns out he'd stumbled upon
one of the best fossil trackways

in the world.

RAY STANFORD: Over 100 tracks,
over -- or nearly 40 mammal
tracks of at least three

and probably five species of
mammals, at least three species
of dinosaur tracks, and probably

two or three species of
flying reptile tracks.

PAMELA KIRKLAND: At
least 110 million years
ago, these dinosaurs
sauropods and nodosaurs,

small mammals, and
flying reptiles, like
the pterosaur, crossed
paths on the 8.5-foot slab

of sandstone.

Because none of the prints
overlap, experts think the
tracks occurred over the course

of few days or hours.

They remained
untouched until now.

This replica is displayed
in Goddard's Earth Science
Building in Greenbelt, Maryland.

The original sits in a
warehouse for further study.

If not for Stanford, the
discovery might have been
lost to construction.

At the time, NASA had
planned to build on the site.

COMPTON TUCKER, NASA: I had
walked by that place probably
30 or 40 times, and I had no

idea there was something
so cool right there.

PAMELA KIRKLAND: Compton Tucker
is a climate researcher at
NASA and oversaw the excavation

of the four-ton stone.

NASA tapped Tucker for
his experience working
on archaeological digs
to find buried ruins.

COMPTON TUCKER: We found
where the sandstone was.

We organized a team
of volunteers to
come in on weekends.

And we dug out all of the
rocks we found in our survey,
and one of those rocks is the

amazing rock which has the
track Ray Stanford found.

RAY STANFORD: These people are
used to looking into space,
not into ancient time, looking

down.

PAMELA KIRKLAND: Stanford has
been looking at tracks for
over 25 years, thanks to his

10-year-old son's
curiosity in dinosaurs.

RAY STANFORD: Joel (ph), who
at a secondhand bookstore said,
"Daddy, let's get this book

on tracking dinosaurs."

And we began to find dinosaur
tracks in the stream, although
we'd read another book that

said that nothing had been
found in the D.C.-Maryland area.

PAMELA KIRKLAND: Since then,
Stanford has tripled the
number of dinosaurs and winged

reptiles identified in
the state of Maryland.

One of his finds, a hatchling
of a baby nodosaur, the only
hatchling of an armored dinosaur

in the world, sits on display
at the Smithsonian National
Museum of Natural History.

RAY STANFORD: This is
my favorite footprint
possibly of all of them.

PAMELA KIRKLAND: He and his
wife, Sheila, estimate they
have collected over 1,000.

RAY STANFORD: In the
middle of this, we have the
adult theropod dinosaur.

PAMELA KIRKLAND: For Stanford,
fossil hunting is second nature.

RAY STANFORD: It's a gift.

It's a habit that grows.

And the more you do it,
the better you get at it.

PAMELA KIRKLAND: After
unearthing his largest
find, the 79-year-old
is still searching for

the next big discovery.

RAY STANFORD: You get
addicted, I confess.

You just keep on tracking.

PAMELA KIRKLAND: For the "PBS
NewsHour," I'm Pamela Kirkland
in Greenbelt, Maryland.