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cont'd
NEW CARNIVORE
Large tooth
from new carnivore.
We long suspected there
was at least one other large meat eater
(at least the size of Suchomimus,
36-feet long) on the scene 110 million years
ago because we have on many occasions found
its dagger-shaped teeth. These flattened
teeth look very different from Suchomimus
teeth. Suchomimus teeth resemble
crocodile teeth - they are cylindrical in
cross-section and hook-shaped - well suited
for catching fish. In fact, the only way
to be sure you have a Suchomimus tooth
and not a crocodile tooth is to examine
the edges for very small serrations, like
the serrations found on the teeth of predatory
dinosaurs like Tyrannosaurus.
Pelvic bone
of a new 110 million year old predatory
dinosaur.
We are zeroing in on
the animal, but are only beginning to make
out what it looked like. It probably wasn't
as common or didn't frequent the river habitat
as much as Suchomimus. The flattened
teeth with the wrinkled enamel, and the
shape of the skull bone over the eye gave
us an early clue that we might be dealing
with a fore-runner of Africa's tyrant dinosaur,
Carcharodontosaurus, a huge dinosaur
that lived 90 million years ago.
One of Gabrielle Lyon's
finds while at Camp 1 confirmed these suspicions.
We now have several jaw bones with teeth
in place, a pelvic girdle, vertebrae - all
consistent with an animal that grew to the
size of Suchomimus, one that may
be an early relative of Carcharodonotosaurus.
We are very excited
about this new dinosaur- it would be nice
to find more of this theropod, but it is
very rare.
NIGERSAURUS
The Nigersaurus
was a 600 tooth plant eater with shovel
shaped head. The team has trenched around
this Nigersaurus fossil
and it is ready for a plaster jacket.
One of the most satisfying
outcomes of Camp 1 is that we have filled
out the skeleton of Nigersaurus,
the 600-toothed plant eater we have come
to know from our previous discoveries. We
are missing only a few bones of the skull,
feet and the tip of the tail.
Nigersaurus we
now know, is a relative of North America's
Jurassic Diplodocus. It used to
be thought that Diplodocus and all of its
close relatives (the diplodocoids) died
out at the end of the Jurassic. We now know
that the group did not go entirely extinct. One
group of these long-necked plant eaters
survived into the Cretaceous period on southern
continents like Africa. Nigersaurus
- with its absolutely bizarre jaw adaptations
- will shortly be the best known of these
Cretaceous descendents.
Partial
jaw of a juvenile Nigersaurus.
Nigersaurus was
not a very large sauropod as sauropods go.
It probably reached a maximum size of 50
feet in length. The discovery of a tiny
jaw of a Nigersaurus hatchling, however,
was quite a surprise! All dinosaurs hatched
from eggs, and even sauropods like Nigersaurus
started out quite small.
We have more than half
the field season ahead of us, but as you
can imagine with this kind of an exciting
start, we are already contemplating how
we will prepare, study, describe and announce
these new findings. Many of them will be
named as new species and together are giving
us the most complete picture of life on
Africa during 110 million years ago.
Paul
Sereno
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