Ten years ago a gay fossil hunter, a professional palaeontologist, Edwin Cadena, uncovered a new species of giant turtle which helps to explain how such creatures could grow so large and what ecological environment could have led to its evolution. Edwin was a member of an expedition from the Smithsonian Tropical Research Institute in Panama and the University of Florida.
They had been alerted to a
potentially rich seam of fossils in a huge open-cast coal mine in Cerrejón in
northern Colombia by a fossil plant in a display case at a coal company. It was
only when a professor from the University of Florida recognised it as part of
an unusual jawbone and not a leaf that fossil-hunters began to get excited
about what else they’d find at the mine.
Studying for an MSc in
Geology at the University of Florida, Edwin Cadena was invited to join the
expedition team that went to Cerrejón. Being a native of Colombia Edwin was an
ideal choice. In 2004 the expedition collected as many fossils from the coal
mine as it could.
They came back several
more years and the specimens were sent to the University of Florida for
cleaning and identification. Three years later a graduate student unpacked one
fossil vertebrae labelled “crocodile”. After it was cleaned up it was obvious
to him that it was too big for a crocodile (specimens aren’t usually examined
in detail on site). When a specialist in fossil snakes saw it he was amazed at
its size and began research into the bone and others bagged up from the same
site in the coal mine. With only an incomplete snake skeleton to go on it took
a couple of years of comparing other known giant snake fossils before
palaeontologists finally revealed that the Cerrejón fossil belonged to the
biggest snake ever known. They gave it the scientific name of Titanoboa
cerrejonensis – literally “titanic boa from Cerrejón”. Later discoveries of
other Titanoboa fossils have confirmed their findings.
Titanoboa was so big that
it could swallow a fully-grown adult crocodile whole. It weighed over a ton,
and about 42 feet long. If you own a car think about this next time you open
any one of the car doors. It doesn’t matter what make of car it is, Titanoboa
would find it a bit of a squeeze getting through that open door, if at all!
Titanoboa was discovered
in rock strata that were formed between 58 and 60 million years ago in what is
called the Palaeocene epoch. That was long after the extinction of the big
Other giant fossils were
discovered at the Cerrejón mines, and that brings us back to Edwin Cadena.
While research was still being carried out on Titanoboa Edwin was back in that
coal mine chipping away at the rock. It was ten years ago this month that he
discovered that brand new species of giant turtle. It wasn’t the largest ever
found, but he was the first human to set eyes on this new animal. It must have
felt like his birthday. Considering he discovered the first bone a couple of
days after his actual birthday, that’s probably true!
In fact there were two
discoveries. First Edwin found a huge fossil turtle shell. It was about 5 feet
7 inches from front to back – just about the same at Edwin’s height. About 200
meters away he found a huge turtle skull. It was of a species previously
unknown to science and Edwin eventually proved it was a new species. He gave it
the scientific name Carbonemys cofrinii (literally “fresh-water turtle in coal,
named after Dr. David Cofrin” – Cofrin funded Edwin’s expedition). Although
there was nothing to link the shell and the skull together directly, and
because no other skulls have been found in the vicinity, it is assumed that
they belong to the same animal.
The Cerrejón mine has
revealed other examples of giant fossils. Why did Titanoboa and Carbonemys grow
so big? The mine used to be a hot swampy environment, hotter than any jungle
today, and palaeontologists believe this may have been the reason. Cold-blooded
reptiles need heat to enable them to move. The bigger the animal the more heat
it requires, so in the hot swamp the reptiles were able to evolve into bigger
The illustration below
gives a better idea of the relative size of these giant reptiles compared to a human,
Edwin Cadena himself. (The reptile silhouettes are representative of a snake and turtle
and are not actual silhouettes of the species named).