Two New Dinosaurs Discovered in Antarctica
some of the planet's harshest conditions, fossil hunters have found
two completely new species of dinosaur in Antarctica. This increases
to eight the number of dinosaur species found on the perpetually
frozen southern landmass." Click
here: Two New Dinosaurs Discovered in Antarctica
New Madagascar Dinosaur Discoveries
About 70 million years ago, the nearly complete
skeleton of a young dinosaur was fossilized on the super continent
of Gondwanaland on what is now called the island of Madagascar.
This was a time when the last of the giant sauropod dinosaurs were
at the height of their development. The fossil included almost a
complete set of 80 to 90 vertebrae—from the neck, back, hip, and
tail as well as a complete skull. The young dinosaur measured 26
feet long from head to tail and "probably weighed about as
much as an elephant," one of the team members from Stony Brook
University in New York, Curry-Rogers said. Because it was a juvenile,
she noted, it was only about half the size of an adult titanosaur.
Fully grown, a titanosaur would be about 50 feet long.
Titanosaur's are a sub-group of the long-necked, plant-eating
sauropods. Other sauropods included the closely related Brachiosaurus,
Apatosaurus, and Diplodocus.
More than 30 kinds of titanosaurs have been identified
so far. Yet according to Curry- Rodgers, how they were related and
what they looked like has been difficult to figure out because until
this discovery no one had found a complete skull or skeleton.
"Since the first titanosaur was found a
hundred years ago, we’ve had no idea of their anatomy. The most
important thing about this discovery is that it gives us our first
idea of what a titanosaur looked like from head to tail."
The researchers named the new dinosaur species Rapetosaurus
krausei. The first part of the name, another researcher explained,
comes from the Malagasy word "Rapeto." It's the name of
a mischievous, mythical giant of Madagascar, a figure somewhat like
Paul Bunyan, a giant woodcutter in American folklore.”
"Since this new species is one of the dinosaur
giants, we thought the name was fitting," she said. The second
word in the scientific name was chosen in honor of expedition leader
Krause. The two researchers said it had a very long neck, a short
tail, and a long, narrow snout. The new skull show that the nostrils
were on top of its head, rather than at the sides of its snout,
like in horses and dogs.
The teeth of Rapetosaurus were "pencil-like pegs,"
Curry-Rogers said. "It's teeth were okay for raking leaves
off trees, but it can't crunch and wasn't a very efficient eater,"
she explained. Included among the fossils were the partial remains
of two other dinosaur species besides Rapetosaurus that are also
new to science. "We've been fortunate enough to make one fantastic
discovery after another, including some of the most complete and
exquisitely preserved dinosaur material in the world," expedition
leader Krause said. Previously, scientists had speculated that Africa,
Madagascar, and other southern landmasses were relatively isolated
during the 35 million years of the Late Cretaceous period and therefore
had no dinosaurs like those that lived in other regions of the world
at about the same time. The first significant dinosaur discovery
by Krause and his colleagues, which came in 1996, challenged that
idea. They uncovered the well-preserved skull of a giant meat-eating
theropod, named Majungatholus, which is a relative of the American
T rex.. Its features resembled those of dinosaur fossils found in
present-day Argentina and India.
Several fossils belonging to the dinosaur Majungatholus,
including an almost complete skull, were found from 1996 to 2000.
The fossils date from 70 to 65 million years ago, during the late
Cretaceous period, right before the huge K-T extinction in which
the remaining dinosaurs, except the avian dinosaurs the birds, went
extinct. Majungatholus atopus was a meat-eating dinosaur called
a theropod. It was up to 30 feet long and was at the top of the
food chain in its locale. It probably ate sauropods, like the recently
named Titanosaur Rapetosaurus krausei. The name Majungatholus is
derived from "Majunga," a district of Madagascar and "tholus,"
which means dome in Latin. Majungatholus belongs to the group of
dinosaurs called abelisaurids, which until now were only found in
India and South America. It is especially similar to the horned
dinosaur Carnotaurus, which is found in Argentina. Finding this
Majungatholus in Madagascar, far from its relatives in India and
South America, has implications for plate tectonics like discussed
In particular, the continent of Gondwanaland may have
had a connecting land-bridge from South America through Antarctica
to India-Madagascar for longer than believed, allowing animals like
Majungatholus to slowly migrate to new, far flung habitats.
This suggests that Madagascar may not have been long
isolated but connected to South America by a land bridge, perhaps
through Antarctica. Krause recently made another discovery in Madagascar
that will add to that debate. In the August 2, 2000 issue of Nature,
he reported finding a tooth in Late Cretaceous rocks that provides
the first evidence of an ancient marsupial in Madagascar. It's intriguing
because all of the island's mammals today are placental, and marsupials
are thought to have originated in the Northern Hemisphere.
Until this new dinosaur discovery, it had been thought
that Majungatholus (then only known from a skull fragment) was a
pachycephalosaurid (a thick-skulled, plant-eating dinosaur) very
similar to Yaverlandia bitholus, the oldest-known pachycephalosaurid
which has been found in Britain. But it turned out that the fragment
was not what it was thought to be and laid to rest a conundrum for
paleontologists at that time.
The team that found the Majungatholus in Madagascar
was led by paleontologist/anatomist Scott Sampson from the New York
College of Osteopathic Medicine at the New York Institute of Technology.
Further study by Raymond Rogers of Macalester College determined
that when times got tough, the Majungatholus even ate his own kind.
“We have the smoking gun in the form of diagnostic tooth marks,
and we can definitely rule out all the other carnivores known to
have been on the scene, he stated firmly. What they are not sure
of if this was predation, which would make them a definite cannibal,
or simply scavenging anything in order to survive hard times.
Meanwhile, the skull and skeleton of the sauropod
Rapetosaurus will help scientists better understand the links between
different groups of titanosaurs and how they're related to other
sauropods. Paleontologists had speculated, for example, that titanosaurs
were closely related to Brachiosaurus. The Rapetosaurus fossils
confirm that close relationship.
Another new Madagascar dinosaur discovery is related
to the raptors. This new fossil, when alive, would have weighed
about as much as a large dog. But the most unique feature of the
newly discovered Masiakasaurus knopfleri is its teeth, some of which
protruded from its jaw almost horizontally.
Scott Sampson, along with other paleontologists, discovered
fossil evidence of this small carnivorous dinosaur on the island
of Madagascar fairly recently. “When we dug up the first lower jaw
bone, we weren’t even sure it belonged to a dinosaur,” said Sampson.
The Masiakasaurus knopfleri’s lower front teeth are
nearly horizontal, with the teeth angle increasing until the dinosaur’s
fourth tooth, after which the teeth are vertical. Although the back
teeth of the dinosaur are similar to other predatory dinosaurs,
their horizontal, conical front teeth “are otherwise unknown among
other [predatory] dinosaurs,” according to the Masiakasaurus’ discoverers.
This dinosaur’s fossils were dated to the Late Cretaceous
period (about 65-70 million years ago). They show a five to six-foot
(about two-meter) long dinosaur that weighed about 80 pounds.
The name of the new dinosaur is
derived from masiaka, the Malagasy word for “vicious” and sauros,
which is Greek for “lizard.” Scientists on these Madagascar finds
often incorporate local language words into the names of the newly
Knopfleri honors musician Mark Knopfler, lead singer
of Dire Straits. The scientists credit Knopfler’s music as a lucky
charm; it seemed that many of their most important discoveries were
made whenever they were listening to his songs.
“Finding fossils entails a heavy dose of serendipity,”
said Sampson, “and we’ll take good luck any way we can get it.”