Deinonychus: The Dinosaur That Sparked a Renaissance

The discovery of Deinonychus, an agile theropod that may have hunted in packs, changed the way we think about dinosaurs -- and inspired 'Jurassic Park' to boot. Learn about Deinonychus and the real (smaller) Velociraptor in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/dinosaurs/deinonychus.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren
Boglebaum here Today. The late nineteen sixties through the seventies
are fondly remembered as the dinosaur Retaissance. There was a
sudden surge of exciting new discourse about our favorite prehistoric beasts.

(00:23):
The idea that birds descend from dinosaurs and now a
scientific consensus gained new traction. At the same time, old
beliefs regarding dinosaur metabolic rates came into question awhere. Previously,
our best scientific guess was that dinosaurs would have been big,
cold blooded lizards and therefore mostly slow and lethargic. During

(00:44):
this time, we started to understand that some might have
been active hunters. And it was all thanks to one
species unearthed in Montana that also became the basis of
Jurassic parks velociraptors. Today, let's talk about Diynonicus. Back in
nineteen thirty one, while exploring southern Montana, paleontologist Barnum Brown

(01:05):
found the incomplete skeleton of a dinosaur that would have
measured some eight feet that's two and a half meters
in length. It was clearly a theropod, a member of
the same group as Alosaurus and Tyrannosaurus rex. This one
had an agile build. Not only was it light boned,
but there were long, wiry extensions on the tail vertebra.

(01:28):
Brown guessed the stiffened the appendage as a whole, helping
the tail act as a better counterweight to the rest
of the body. Though Brown planned to write a manuscript
about this intriguing new dinosaur, he was unable to finish
before his death in nineteen sixty three, But in his
later years, Brown showed the skeleton to a young researcher
named John Ostrom. August of nineteen sixty four found Ostrom

(01:52):
hunting for early Cretaceous dinosaurs around Bridger, Montana. Under the
summer sun. He and a colleague discovered the clawed hand
of a theropod peeking out of the earth. Then a
foot turned up, so did thousands of other bones. Ostrom
soon realized he was dealing with the same species that
Brown had unearthed decades earlier. He named the creature Dinonicus

(02:15):
anti rappus. At the time, he had recovered the bodies
of four individuals at a single Montana quarry, all lying
in close proximity to some bones from t Nantosaurus, a
plant eating dinosaur with a beak and a long tail
that would have grown to over twice the size of
a Dinonicus, possibly over five times the size. Dinonicus means

(02:37):
terrible claw. This was inspired by the huge curved claws
that topped the second toe of each foot. To Ostroum,
this was a revelation. Dinonicus would have held these claws
off the ground as it walked, standing sort of perched
with light bones, battle ready and athletic. Historically, dinosaurs were
thought to be plotting beasts, Buticus contradicted this assumption. Ostrom

(03:03):
wrote in nineteen sixty nine, it must have been a
fleet footed, highly predacious, extremely agile, and very active animal,
sensitive to many stimuli and quick in its responses. Ostrom's
work on Diynonicus was a catalyst for the dinosaur renaissance,
but you don't have to be a science enthusiast or
a history buff to appreciate its impact. The famous, though

(03:27):
fictionalized velociraptors from Jurassic Park were based on Dinonicus. Don't
get us wrong, there was an actual theropod named Velociraptor
that lived in Central Asia some seventy five to seventy
one million years ago. However, it was way smaller than
the creatures shown in the popular movies, which can look

(03:47):
a grown man in the eye. The real Velociraptor stood
just twenty eight inches tall at the hip. That's seventy
two centimeters, closer to the size of a wild turkey,
just with the longer body and more weight on its bones.
Dinonicus wasn't all that big either, but would have stood
about thirty eight inches tall at the hip or one meter,

(04:08):
and could grow more than eleven feet long that's three
and the third meters, so it would have been staring
into sam Nil's chest, not his eyes. Both Velociraptor and
Dinonicus belonged to the same family of bear pods, the dromiosaurs,
found in Eurasia, Africa, and the Americas. The dromiosaurs had
knife like teeth, big skulls, and long limbs. At least

(04:31):
some probably all of them had feathers to boot, but
let's revisit those terrible claws. Dinonicus was not unique in
having an enlarged talon on the second toe of each foot.
It was a standard dromiosaur feature, said toes were hyper extensible,
they could be pulled back into an almost vertical position.

(04:53):
Besides keeping the claw tips sharp, this trait gave them
a wide arc of motion. Ostrum Dgennonicus leaping through the air,
slashing wildly with the curved daggers on its flexible toes.
But more recent modeling has painted a different picture. In
twenty nineteen, paleontologist Peter J. Bishop published a three D

(05:15):
Dinonicus hind limb reconstruction. According to his simulations, the toe
claws couldn't exert very much force. They were probably better
at grasping prey than disemboweling it. And remember the long
rods on Dinonicus's tail vertebra, Velociraptor, uteriraptor and other dromiosaurs
had those two experts think that they made all but

(05:38):
the base of the tail very rigid. That sort of
like a tightrope walker's long pole. It would have kept
the animal upright and balanced while moving. One velociraptor fossil,
discovered in nineteen ninety nine, with its tail in an
s curve, may challenge that view, though it's hard to
say whether the shape was the result of motion during
life or the settling of the bones after death. Speaking

(06:02):
of fossils, let's go back to Ostrum's find a four
carnivorous Dynonicus in close proximity to a herbivorous but much
larger to Nontosaurus. It got him thinking, he wrote in
nineteen sixty nine. The multiple remains suggest that Dinonicus may
have been gregarious and hunted in packs. Author Michael Crichton

(06:24):
ran with the idea. His original Jurassic Park novel published
in nineteen ninety, which was the basis for Steven Spielberg's
nineteen ninety three movie adaptation, describes the raptors attacking their
prey in organized packs, working together to bring down dinosaurs
and humans alike. Yet scientists have cause for skepticism. Habitual

(06:46):
strategic pack hunting is quite rare among modern animals. Perhaps
Dinonicus and other dromiosaurs were loners for the most part,
but went into spontaneous group feeding frenzies every now and then.
After all, that's how modern komodo dragons roll. However, some birds,
the closest living relative of dinosaurs, have been observed hunting

(07:09):
in pairs, like peregrine falcons and Harris's hawks of the
American Southwest coordinate in groups of five, communicating through movements
and converging on prey from multiple angles. So maybe Crichton's
raptors and Prehistory's dromosaurs hunting like this isn't too far
fetched after all. Today's episode is based on the article

(07:35):
how Dynonicus Upended the way we look at Dinosaurs on
how stuffworks dot com, written by Mark Mancini. Brainstuff is
production of iHeartRadio in partnership with how stuffworks dot Com.
It is produced by Tyler Klang. Four more podcasts from
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