Are You Picturing the Right Brachiosaurus?

Confusion about what a Brachiosaurus is started the moment paleontologists discovered one. Learn about these long-armed sauropods (and about the dino cousin they're often pictured as, Giraffatitan) in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/dinosaurs/brachiosaurus.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Lauren Vogelbaum. Here, you know you've made it in this
wild world of ours when astronomers name something after you.
And On April eighth of nineteen ninety one, scientists at
the European Southern Observatory spotted a previously unknown asteroid in

(00:24):
orbit between Mars and Jupiter. Since the thing needed a name,
they called it nine nine five four. Brachiosaurus a long armed,
long necked plant eating dinosaur. A Rachiosaurus resided in what's
now North America during the late Jurassic Period, about one
hundred and fifty five to one hundred and fifty million

(00:44):
years ago. Today, the animal lives on in our popular culture.
For example, in the original Jurassic Park film, a herd
of them grazing are the first majestic creatures we see,
set to John William's sweeping score. But this dinosaur fame
comes with an astrisk. Portrayals of the giant reptile in
the Jurassic Park films were largely based on a different dinosaur.

(01:07):
Its taxonomical name is Giraffetitan bronchi. This is a mix
up that goes back a long way in paleontology anyway, Okay.
In the year nineteen hundred, while on a fossil finding
trip around Grand Junction, Colorado, paleontologist Elmer Riggs and his
assistant H. William Menki came across a very large and

(01:31):
very incomplete skeleton of a sauropod. The sarropods were a
diverse group of herbivorous dinosaurs. Generally, they had long necks,
small heads, and column like legs. Many species were flat
out enormous. Indeed, the biggest land animal to ever draw
breath was undoubtedly a sarapod, but the skeleton Rigs and

(01:55):
Menkey on Earth was missing several pieces. All that remained
were some ribs and vertebraates, a partial hip, an incomplete
shoulder blade, and two gigantic limb bones. Obviously, this animal
was a sauropod, but it had weird proportions. Mossauropods found
before the year nineteen hundred had forelombs that looked much

(02:15):
shorter than their hind limbs. Yet the situation was reversed here.
Riggs was fascinated by the right humorus, or upper armbone
that came with the skeleton at six feet or two
meters in length. It was slightly longer than the dinosaur's
right femur or upper leg bone, which was also preserved.

(02:36):
In an article published in nineteen oh one in the
journal Science, Riggs wrote that, along with some other bones,
the quote extraordinary length of the humorists suggests an animal
whose shoulders would rise high above the pelvic region, giving
the body something of a draft like proportion. Two years later,
in nineteen oh three, he named the new animal Brachyosaurus althorax.

(02:59):
The name Brachiosaurus means arm lizard, while the species name
alt thorax roughly translates to deep chested, nice and descriptive,
but okay. Time for a plot twist. Between nineteen oh
nine and nineteen thirteen, German scientists working in East Africa
removed two hundred and twenty five tons of fossils from

(03:20):
mainland Tanzania, which was part of a German colony back then.
The piece de resistance another massive sauropod skeleton. Unlike the
incomplete Colorado specimen, this individual came with an albeit partial skull,
plus most of the ribs and vertebra were recovered. They
were identified as Brachiosaurus. Material and eventually assigned to a

(03:44):
new species, Brachiosaurus bronchi. That African giant stretched over eighty
feet or twenty five meters long and could have carried
its head about forty feet or thirteen meters off the ground.
The towering specimen, and now on display at the Berlin
Natural History Museum in Germany, is a single tallest mounted

(04:05):
dinosaur skeleton in the world. Crucially, Brochiosaurus bronchi gave paleo
artists more fossils to work with than North America's Bronchiosaurus
alta thorax. Ever, did the effects teams behind Jurassic Park
modeled their Bronchiosaurus design on the African species. Other artists

(04:25):
have done likewise over the years. Then things got complicated.
One Gregory S. Paul, a renowned dinosaur illustrator, pointed out
some anatomical differences between the two Brochiosaurus species in nineteen
eighty eight. He claimed the tusar pods were so distinct
from each other they really didn't belong in the same genus. Later,

(04:49):
a two thousand and nine study written by Michael P.
Taylor and published in the Journal of Vertebrate Paleontology concurred.
Brochiosaurus Bronchi has since been reclassified and renamed. It's now
known as Giraffatitan bronchi. But okay, now that we've met Giraffatitan,
let's get to know the real Brochiosaurus, shall we? Because

(05:12):
of all the naming drama, Brochiosaurus altathorax, the dinosaur that
Elmer Riggs described in nineteen oh three, is the only
Brochiosaurus species that experts currently recognize. Brachiosaurus had a tail
that was both longer and taller than Gerrafhatitans. Also, as
Taylor wrote in two thousand and nine, it carried a
greater proportion of its mass on the forelimbs. Hey, you've

(05:35):
got extra large arms, you might as well use him right.
There's no doubt that Brochiosaurus was a hefty beast. One
twenty seventeen paper published in the Journal Paleontology gave a
mass estimate of sixty four tons for Bronchiosaurus. Other researchers
think the dinosaur was lighter, perhaps to picking the scales
at only forty four tons or so. Judging by the

(05:59):
known false Brachiosaurus was probably around eighty feet or twenty
five meters long. At the shoulder, it might have stood
twenty feet or six meters tall, though it could lift
its head much much higher. The exact shape of that
head is debatable. A possible Brachiosaurus skull emerged in Central
Colorado during the eighteen eighties. However, apart from a single

(06:21):
neckbone which was accidentally destroyed, the head was found in isolation,
so as of this writing, there's no way to be
sure if it belonged to a Brachiosaurus or some altogether
different sauropod. Besides Brachiosaurus, there were loads of other long
necked dinos stamping around North America during the Late Jurassic period.

(06:42):
A prehistory buffs should be well acquainted with the Morrison Formation,
internationally famous for its rich fossil record. This is a
geologic sequence of shales, sandstones, and limestones that range from
one hundred and fifty five to one hundred and forty
eight million years old. The Morrison runs all the way
from Monte Hannah and the Dakotas to New Mexico and Arizona.

(07:03):
Brochiosaurus altathorax is just one of many sauropods that have
been found in these rocks. By some counts, about thirty
distinctive sauropod species lived in what's now the Morrison Formation,
including species of Diplodocus and Brontosaurus. It's fun to think
about how such giant animals could have coexisted, Though not

(07:25):
all of sauropods represented in the various Morrison deposits lived
at the exact same time as for Brochiosaurus. The good
old arm lizard still makes headlines now and then. A
juvenile sauropod found in a Wyoming quarry was tentatively identified
as a young Brochiosaurus in twenty twelve. Measuring around six

(07:45):
feet or two meters long, the little tyke would have
been a far cry from the titan that Rigs and
Menkey discovered. Like they say, big things have small beginnings.
Today's episode is based on the article will the real
Brachysaurus Please Stand up? On HowStuffWorks dot Com? Written by

(08:06):
Mark Mancini. Brain Stuff is production by Heart Radio in
partnership with HowStuffWorks dot Com and is produced by Tyler Klang.
Four more podcasts from my heart Radio, visit the iHeartRadio app,
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