When I was little one of my favorite movies was "We're Back: A Dinosaur Story".
It's a ridiculous cartoon about dinosaurs showing up in a big city. Now, the
Brontosaurus can say "I'm back"!
For many years paleontologists have insisted that the species
was incorrectly labeled and was being confused with a similar dinosaur,
Apatosaurus. But now…they're back!
A team of paleontologists led by Emanuel Tschopp at the New
University of Lisbon in Portugal has just completed a massive computer analysis
of fossils in a group of dinosaurs called Diplodocids that includes the
Brontosaurus. The group found that Brontosaurus is in a group of its own. Its
fossils share distinct, incomparable bone features-enough for it to reclaim its
iconic genus name. Image Credit
Although the research
is well done and very convincing, many paleontologists have trouble
accepting the news. The Brontosaurus holotype (the fossil to which every other
fossil in that group is compared) was found in Montana in 1877. At this time
naming a new dinosaur often trumped scientific scruples. But in 1903,
paleontologists decided that the naming was a bit hasty and the new dino was
just a smaller version of the Apatosaurus. In the 1970s paleontologists went
back to the original find and discovered that it was actually a mishmash of two
completely different dinosaurs with the skull from one plopped onto the
skeleton from another.
But Tschopp didn't give up. His group collected a major
trove of fossil data on almost all the known Diplodocid fossils. Then they ran
the data through statistical programs which grouped the dino fossils based on
their various bone peculiarities.
Their data matched how paleontologists currently view the
evolutionary tree of these dinosaurs. But it also led them to a few surprises!
According to Tschopp, there are seven specific bone differences that make the
body of the original Brontosaurus its own species and genus, not just some
other big dino that's been mislabeled. Image Credit
The differences are subtle. The tail vertebrae in dinosaurs
related to the Brontosaurus have spiny prominences called "neural spines" and
for most of these dinosaurs these spines project backwards, in the Brontosaurus
they're more straight up out of the back. Brontosaurus's hips are unusual, with
two bones meeting in a curious junction, and its lower leg fibula meets its
ankle bones in an equally unusual manner.
Some paleontologists (and the entire dinosaur loving public)
are excited that the Brontosaurus has been corralled back into the realm of
science, if only because it's really become a piece of Americana.
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Re: Brontosaurus vs Apatosaurus
