A recently discovered prehistoric
monster snake provides answers about the past - and raises questions for the
future.
Around 58 million years ago, a monstrous snake slithered out of the swampy
jungles of South America and began a reign of terror.
Weighing more than a tonne and measuring 14m (approximately 50ft) the giant
reptile could swallow a whole crocodile without showing a bulge. But a few years
ago, scientists never even knew it existed.
"Never in your wildest dreams do you expect to find a 14m boa constrictor.
The biggest snake today is half that size," says Dr Carlos Jaramillo, a
scientist with the Smithsonian Tropical Research Institute and part of the team
that made the discovery.
'World of lost
reptiles'
Thought to be a distant relative of the anaconda and boa constrictor, the
snake - named Titanoboa - was not venomous. Instead, it crushed its
prey with the constricting force of 400lbs per sq inch - the equivalent of lying
under the weight of one and a half times the Brooklyn Bridge.
“Start Quote
Changing climates and changing continents are the fuel of
evolution. But things that happen very quickly can result in the types of change
we might not view very positively”
End
Quote Jonathan Bloch University of Florida
The fossils were exposed by excavation at the massive
Cerrejon open-face coal mine in northern Colombia. In 2002, scientists had
discovered at that site the remains of a tropical rainforest from the Palaeocene
Epoch - perhaps the planet's first.
As well as fossilised leaves and plants, they unearthed reptiles so big they
defied imagination.
"What we found was a giant world of lost reptiles - turtles the size of a
kitchen table and the biggest crocodiles in the history of fossil records," says
Jonathan Bloch, an expert in vertebrate evolution at the University of Florida.
They also found the vertebrae of a colossal snake.
"After the extinction of the dinosaurs, this animal, the Titanoboa,
was the largest predator on the surface of the planet for at least 10 million
years," says Dr Bloch. "This was a major animal in any sense of the
imagination."
Search for skulls
But scientists needed the snake's skull to get a full picture of how it
looked, what food it ate and how it might be related to modern species. Last
year, a team set out to find it, with little expectation of success. Because the
bones of a snake's skull are so fragile, few survive.
"Unlike our skulls, snake skulls aren't fused together. Instead they're
connected with tissue," says Dr Jason Head, a snake specialist from the
University of Nebraska.
"When the animal dies, the connective tissue decomposes and all the
individual bones are generally dispersed. They're very thin and fragile too and
often get destroyed. Because Titanoboa is so big and the skull bones
are so large, it's one of the few snakes that do make it into the fossil
record."
To their amazement, the team recovered the remains of three skulls from which
the reptile could be accurately reconstructed for the first time.
Giant animals in history
- Blue whale: still swimming today, blue whales measure 30m (100ft) long
- Brachiosaur: this dinosaur measured 23m (75ft) long and 12m (40 ft)
high
- Chan's Metastick: this stick insect, native to Borneo, measures 56.7cm,
(22.3 in)
- Pterosaurs - this flying reptile had a wingspan of 5.1 meters
(16ft)
Source: US Geological Survey, National Geographic, New Zealand Museum of
Natural History
From that, they were able to get a better sense of how
Titanoboa lived and looked. A life-sized replica is now on display at
the Smithsonian Natural History Museum in Washington, and will begin a
nationwide tour in 2013.
Aside from the excitement of discovering a new and enormous species of snake,
the reptile can tell scientists a lot about the history of the Earth's climate -
and offer a glimpse of the possible effects of global warming today.
Snakes are unable to regulate their own temperature and depend on external
heat to survive.
"We think the Titanoboa became this large because it was much warmer
on the equator after the dinosaurs died 60 million years ago," says Dr Bloch.
"We think that's why reptiles in general were larger.
That ability to thrive in a warm climate could be relevant in the event that
global temperatures rise according to the projections of climate scientists, Dr
Bloch adds.
"It's evidence that ecosystems can thrive at temperatures of the levels that
are being projected over the next one or two hundred years."
Return of
Titanoboa?
But the climate changes that produced Titanoboa took millions of
years. Scientists are less certain about the effects of sudden temperature
change.
"Biology is amazingly adaptable. Changing climates and changing continents
are the fuel of evolution. But things that happen very quickly can result in the
types of change we might not view very positively," says Dr Bloch.
 |
| Add caption |
The Cerrejon open-face coal
mine where the fossils were discovered
As well as being warmer, CO2 levels were also 50% higher during the period of
the Cerrejon rainforest.
"One big lesson we are learning from the fossils in Cerrejon is that tropical
plants and the ecosystem in general have the ability to cope with high
temperatures and high levels of CO2, another major concern with the current
trend of global warming," says Dr Jaramillo.
"Perhaps the plants and animals of the tropics today already have the genetic
ability to cope with global warming."
Does that mean the Titanoboa could one day return?
"As the temperature increases, you have the probability they will come back,"
says Dr Jaramillo. "But it takes geological time to develop a new species. It
could take a million years - but perhaps they will!"
