How Did Utahraptor Work?

The Utahraptor was the largest known raptor -- up to 800 pounds, about the size of a large black bear or small grizzly. Learn how salt helped preserve their fossils in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/dinosaurs/utahraptor.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren Vogelbaum. Here,
Utah is prime dino hunting country. Of fossils representing more
than one hundred and fifteen dinosaur species have been unearthed
inside the state's borders. Most of these species weren't identified

(00:22):
until recently, as in within the past twenty nine years. Truly,
this is a golden age for paleontology in the Rocky
Mountain West. One of the beasts found there, indeed, one
that seems to be totally unique to Grand County, Utah,
is the Utah raptor, a carnivorous dinosaur with frightful claws.

(00:45):
It lived around one hundred and thirty five million years
ago and boasts a few Jurassic Park connections, as the
name raptor suggests. Yet, by various estimates, Utah Raptor could
grow to be fifteen, eighteen, or perhaps even twenty three
feet long. That's from about four and a half to
seven meters. That could make this dino a whole lot

(01:07):
bigger than any raptor in Steven Spielberg's filmography. The Utah
Raptor was named the state's official dinosaur in twenty eighteen.
But this eventual home of the Utah Jazz basketball team
and the Great Salt Lake looked very different. When Utah
Raptor reigned about one hundred and thirty five million years ago,

(01:30):
the Jurassic period of Earth's geologic history was coming to
a close. It was followed by the Cretaceous period, which
lasted until a mass extinction event about sixty six million
years ago that killed off the last of the dinosaurs
except for birds. Utah Raptor lived early in the Cretaceous.
At that time, the face of Utah was transforming, thanks

(01:53):
in no small part to everyone's favorite pretzel topping salt.
Without it, we might not know that utah Raptor ever existed. Okay, along,
before even the first dinosaurs showed up, there was a
deep basin along what's now the Utah Colorado Border. Seawater

(02:14):
flowed in and as it evaporated, it left behind giant
piles of salt that were literally thousands of feet tall
that is hundreds and hundreds of meters. A rocky debris
later covered up those salt beds. As time passed, the
now underground cache of salt started getting deformed by this

(02:36):
heavy overlying material. Parts of Utah's terrain were raised up
by the shifting salt, other spots dipped down. Grand County
was one of those places where this movement or salt
tectonics created big depressions across the landscape, and in the

(02:56):
early Cretaceous these became the home of vibrant ponds and lakes.
It was a perfect environment for future fossils. A North
America was a fairly dry place in those days, an
erosion was rampant, but here the inflow of water and
sediment to these low elevation lakes did a good job

(03:17):
of covering up and preserving the bodies of the animals
that died there, animals like the Utah raptor. The two
oldest assemblages of Cretaceous dinosaurs in the entire North American
fossil record are both preserved in Grand County rocks. For
the article this episode is based on How Stuff Works,

(03:39):
spoke via email with Jim Kirkland, Utah's official state paleontologist.
He explained about one hundred and thirty five million years ago,
local subsidence in Grand County uniquely preserved a series of
lakes and ponds teeming with lungfish, chain mail covered bony fish,
and spiny sharks. Utah raptor stocked iguanodonts and young sauropods,

(04:03):
while the heavily spined and armored gastonia looked on. Iguanodonts
were beaked animals, Sauropods were long necked giants, and Gastonia
was a type of armor plated dinosaur built like a
living tank. All of them had vegetarian diets, though flowering
plants hadn't developed yet. Most of the vegetation there consisted

(04:26):
of conifers and ferns. A utah raptor was the biggest
type of raptor, with an estimated weight of about six
hundred to eight hundred pounds or two hundred and fifty
to three fifty kilos. They would have been about the
size of a large black bear or a small grizzly.
As for the infamous velociraptor, it likely weighed in at

(04:49):
just eighty five pounds or so about forty kilos. A
native of Late Cretaceous Asia, the real velociraptor was a
small bodied predator far removed from its Hollywood name sake.
The raptors in the Jurassic Park franchise were inspired by
larger species, but like all of these relatives, utah raptor
had an outsized, sickle shaped claw on each foot. The

(05:13):
animals held these claws upright as they walked. The claws
had a core of bone measuring up to eight point
seven inches that's twenty two centimeters long, and that's just
the tip of the iceberg. Like modern eagles, utah raptor
must have had keratin sheets covering its clawbones, which would
have made these weapons even bigger than their naked skeletons

(05:36):
suggest a utah raptor's arsenal was rounded out with long
claw tipped arms and a mouthful of serrated teeth, all
the better for tearing flesh technically. The first utah raptor
fossils on record were discovered by paleontologist Jim Jensen of
Brigham Young University in nineteen seventy five. However, and nobody

(06:00):
knew quite what to make of these until a team
led by Kirkland dug up another set of raptor bones
in nineteen ninety one. A utah raptor got its official
name when Kirkland and his colleagues published a paper introducing
the animal in nineteen ninety three, which fittingly is the
same year that Jurassic Park was stomped into theaters. The

(06:21):
creature's full scientific name utah Raptor Ostrom Mazie salutes raptor
expert John Ostrom and animatronics creator Chris Mays, who helped
the research effort. The scientists did consider calling the dino
utah Raptor Spielbergey after a certain movie director, but that
never came to pass. Utah Raptor remains are known from

(06:45):
four different localities across Grant County. One of these sites
has yielded a nine ton sandstone megablock filled with assorted
dinosaur bones. According to researchers, that's probably what's left of
a Cretaceous quicksand type pit. Some iguanadont bones are included
in the mix, but the real highlight is the raptor material.

(07:07):
Kirkland says that the block has yielded fossils from dozens
of individual utah raptor, and in a stroke of luck,
many of those were babies or juveniles when they died.
That could bring us a few steps closer to understanding
how this fearsome predator grew up. Today's episode is based

(07:30):
on the article utah Raptor the Salty Saga of a
Killer Dinosaur on how stuffworks dot Com, written by Mark Mancini.
Brain Stuff is production of iHeartRadio in partnership with how
stuffworks dot Com and is produced by Tyler Klang. For
four more podcasts from my heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you listen to your favorite shows.

(08:00):
Yes