The
Brontosaurus as Marsh envisioned him: wrong head,
wrong lifestyle. (Copyright Lee Krystek,
2002.)
There was a time when the dinosaur named Brontosaurus
evoked images of a monstrous beast with four legs, a long, graceful
neck dragging an even longer tail through primeval swamps. The
meaning of the name, "Thunder Lizard," seemed perfect
for an animal who must have shook the ground with every step he
took. Thousands of children knew this dinosaur by that name. It
even appeared as the symbol of a major oil company and starred
as one of four ancient, extinct reptiles featured on U.S. postal
stamps.
Since the 1980's, however, this name has disappeared
from books and museum exhibits about dinosaurs. The famous beast
was suddenly gone. Surprising, however, in 2015 he may be making
a comeback. Why did he leave, and now why has he now returned?
Casualty
of the "Bone Wars?"
The Brontosaurus, a member of a family of dinosaurs
that walked on four legs with long necks and long tails called
sauropods, was the victim of a war that was played out
over a hundred years ago. Starting in the late 1860's, two of
America's most prominent paleontologists, Edward Drinker Cope
and Othniel Charles Marsh, had a falling out. Cope claimed that
Marsh had paid quarrymen in New Jersey to divert fossils they
found for him to Marsh. Personal attacks between the men, thinly
veiled as "scientific criticism," followed in articles
that they wrote for publication. Later, each would send teams
into the fossil fields of the West where they would fight over
digging rights amid claims that the other side had destroyed or
damaged fossils in order to block their rivals from getting a
hold of them.
One outgrowth of these "bone wars" was an
unscientific competition between Cope and Marsh to see who could
discover the most species of extinct beasts. In their rush to
beat each other to the next find, the scientists often based their
claims on incomplete or inaccurate data.
Othniel
Charles Marsh
In 1877 Marsh wrote a short two-paragraph article
for the American Journal of Science. The article, entitled
"Notice of New Dinosaurian Reptiles from the Jurassic Formation,"
didn't have illustrations and included only a description of the
animal's vertebral column, but he named the creature anyway. Marsh
estimated that the Apatosaurus, meaning "deceptive
lizard", was fifty feet in length. Marsh followed this article
with another one in 1879 where he showed a sketch of the creature's
pelvis, shoulder blade and vertebrae.
In that same year, in another short article in
American Journal of Science, Marsh claimed finding another
dinosaur based on a description of the pelvis and vertebrae. He
named this one Brontosaurus and estimated it to be seventy
to eighty feet in length.
The Brontosaurus soon went on to become one
of the most famous dinosaur species of all time. A nearly complete
skeleton found by Marsh was mounted in Yale's Peabody Museum.
There it captured the public's imagination as did a beautiful
illustration Marsh published in The Sixteenth Annual Report
of the US Geological Survey, 1895. The Yale skeleton was the
first sauropod dinosaur put on display anywhere in the world when
it was mounted in 1905 and the animal was clearly labeled as a
"Brontosaurus."
In contrast the few unspectacular Apatosaurus
bones Marsh found were never augmented with a full skeleton.
Marsh's
30-Ton Mistake
A
rare, souvenir Brontosaurus model from the Sinclair
exhibit at the 1964-65 World's Fair.
In his rush to beat Cope, Marsh had made a mistake,
however. The Apatosaurus was not a separate species, but
simply a juvenile example of Brontosaurus. In 1903 Elmer
Riggs of the Field Museum in Chicago was studying Marsh's work
when he found this mistake:
...the writer is convinced that the Apatosaur specimen
is merely a young animal of the form represented in the adult
by the Brontosaur specimen.
Riggs, following the naming rules for animals that
applied at the time added:
...In view of these facts the two genera may be
regarded as synonymous. As the term"Apatosaurus" has
priority, "Brontosaurus" will be regarded as a synonym.
Despite the poor Brontosaurus losing its official
status very early in the 20th century, the name continued to be
used in popular books, semi-technical articles and even on museum
displays. The Brontosaurus became the symbol for Sinclair, a petroleum
supplier, and a full-sized model made its appearance at the oil
company's exhibit at the 1964-65 New York World's Fair.
The question of the popular Brontosaurus name
verses the technically-correct Apatosaurus name came to
a head in 1989 when the U.S. Post Office decided to release a
set of four stamps illustrating "dinosaurs." One in
the series was a picture of a large sauropod labeled Brontosaurus.
This upset some dinosaur enthusiasts who accused the Postal Service
of promoting scientific illiteracy, an ironic accusation given
the number of museums that had the animal mislabeled for decades.
While there was a hue and cry over the Brontosaurus name, few
even mentioned the other, more glaring error, which was the inclusion
of a Pteranodon (a flying reptile) in a set of dinosaur stamps.
By definition dinosaurs do not have wings.
The set of
U.S. Postal stamps that ignited the controversy in 1989.
(Courtesy US Postal Service)
A few prominent people came to the defense of the
Brontosaurus and the Postal Service. Stephen Jay Gould,
the noted biologist, pointed out that the issue was a tempest
in a teapot in his famous article, "Bully for the Brontosaurus"
written for Natural History magazine. Robert Bakker, the
celebrated paleontologist and curator of the Tate Museum in Casper,
Wyoming, also continues to use the popular Brontosaurus
label instead of Apatosaurus.
To add insult to injury, the poor Brontosaurus not
only got a name change, but it was discovered that he had the
wrong head, too. One item that was not found in the excavation
with Marsh's Yale skeleton was a skull. Marsh mounted a head found
at a different location to complete the exhibit. For many years
scientists suspected that Marsh had gotten the wrong skull, but
it wasn't until 1970 that two scientists, John McIntosh from Wesleyan
University and David Berman of the Carnegie Museum, proved it.
The head that Marsh had mounted was from another sauropod named
Camarasaurus. The proper Brontosaurus/Apatosaurus skull
actually had a slightly longer snout and looked a lot like the
skull of another sauropod called Diplodocus.
Thunder
Lizard's Revised Lifestyle
Marsh's Brontosaurus would wind up getting
both his name and his head changed, but it isessentially still
the same animal. It it wrong to refer to an Apatosaurus
as the Brontosaurus? Not really. The popular synonym has
been around for many years and its meaning, "Thunder Lizard,"
is highly descriptive to the sound the animal made. What sense
does the name "deceptive lizard" make? How deceptive
can a 70-foot long, 30-ton animal be?
Video:
The Great Bone War or Requiem for a Brontosaurus
Much more important than the question of names is
what we know about how the animal actually lived. Today, scientist's
vision of the habits and habitat of the Apatosaurus are
quite different than what Marsh and other early paleontologists
had thought. Early analysis suggested that the animals must have
been weak because their small heads could only chew the minimum
amount of food necessary to fuel such a big body. So weak, in
fact, that large sauropods were thought to be slow, unable to
lift their bulky tails off the ground and only able to support
their massive weight by living in shallow lakes and swamps where
water floated their bulk.
Paleontologists like Bakker showed that this image
was wrong. No Apatosaurus skeleton has been found in an
ancient body of water and its feet were not at all suited for
walking through marshy and muddy ground. In fact, Bakker notes
in his book Dinosaur Heresies, an analysis of changes in
geology over time suggest that large sauropods moved out of areas
as they became wet: they didn't like swamps at all.
Also, a careful reconstruction of the tail shows that
it was probably held aloft and could be swung back and forth,
perhaps for defense. The sauropod's small head was not a limit
on how much it could eat because the animals didn't chew their
food in their mouth. Like many modern birds (and crocodiles),
they grind up food in a lower part of the stomach called the gizzard.
Researchers have recovered stones from sauropod excavations that
the animals swallowed and that lay in the gizzard to aid in the
the grinding process. Because of this Bakker has suggested these
huge animals may have been so active that they could stand on
their rear legs to reach high plants or engage in mating battles.
So, even if the poor Brontosaurus's name was
a casualty of the "bone wars," at least eventually paleontologist
have gotten his lifestyle right.
But is
the Brontosaurus Back?
In 2015 a study led by Emanuel Tschopp, a vertebrate
paleontologist at the New University of Lisbon, took a new look
at a number of sauropod fossils. The scientists analyzed 477 physical
features of some 81 specimens by traveling around to museums across
the world in an attempt to understand the relationships between
them. They found evidence that the Brontosaurs was indeed a separate
species from the Apatosaurus after all. "The Brontosaurus can
be distinguished from Apatosaurus most easily by the neck," said
Tschopp," which is higher and less wide." In fact, the study suggests
there might actually be three species of brontosaurus: Brontosaurus
excelsus, the one Marsh first found, as well as a Bontosaurus
parvus and a Brontosaurus yahnahpin.
Even though it may take more than one study to convince
some scientists, it seems likely that the venerable sauropod may
soon find his name back in museums to the delight of dinosaur
fans around the world.
The
Brontosaurus/Apatosaurus liked dry floodplains, not
swamps, as once thought. (Copyright Lee
Krystek, 2002.)
A
Partial Bibliography
Bully
for the Brontosaurus by Stephen Jay Gould, W.W. Norton &
Company, 1991.
The
Dinosaur Heresies by Robert T. Bakker, Willaim Morrow and
Company, Inc. 1986.
The
Ultimate Dinosaurs, Parragon Books.
2000.
Copyright Lee Krystek
2002-2015. All Rights Reserved.