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NSF PR 98-27 - May 14, 1998
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Remarkable Skull of Predatory Dinosaur Unearthed on
Madagascar
Several specimens of a large predatory dinosaur --
including a nearly complete, exquisitely preserved
skull -- were recently recovered on the island of
Madagascar. The discovery is announced in this week's
issue of the journal Science by a team
of researchers funded by the National Science Foundation
(NSF) and led by paleontologist/anatomist Scott Sampson
of the New York College of Osteopathic Medicine of
the New York Institute of Technology.
The 65- to 70-million-year-old fossils, attributed
to an animal called Majungatholus atopus (a theropod
dinosaur), and dating to the Late Cretaceous period,
were unearthed on an international expedition conducted
by Science paper co-author David Krause
of the State University of New York at Stony Brook.
"The specimens of Majungatholus represent another
in a series of remarkable discoveries by this research
team," said Christopher Maples, director of NSF's
geology and paleontology program, which funded the
research. "The Cretaceous period in Madagascar has
rapidly become among the most important fossil localities
of any age in the world."
Theropod dinosaurs have been known from Madagascar
for over a century, but almost solely on the basis
of isolated teeth -- hundreds of them, each with tiny
serrations indicating the predatory habits of the
animal. "Our primary goal was to find the owner of
those teeth and, as luck would have it, we hit the
paleontological jackpot," explained Sampson. "This
extraordinary skull ranks among the best known for
any dinosaur."
With a total body length of almost 30 feet, Majungatholus
was the top predator of the time on Madagascar, likely
feeding on the massive long-necked sauropod dinosaurs
also found there.
Majungatholus was originally named for an isolated
skull fragment thought to belong to a pachycephalosaur,
or dome-headed dinosaur. The new skull, with an equivalent
bony bump above the eye sockets, demonstrates that
Majungatholus was not a "bone-head" at all, but rather
a carnivorous dinosaur, a distant cousin of the infamous
Tyrannosaurus rex.
Majungatholus belongs to an enigmatic group of theropods
known as abelisaurids, otherwise recovered only from
India and South America. In particular, Majungatholus
shares numerous specialized features with the horned
theropod Carnotaurus in Argentina. The occurrence
of such closely related dinosaurs on widely separated
landmasses may have implications for plate tectonics,
the theory that landmasses shift their relative positions
as they move slowly across the face of the earth.
Madagascar was once part of the southern supercontinent
Gondwana that fragmented during the heyday of dinosaurs.
The known distribution of abelisaurid theropods, as
well as that of fossil mammals, is consistent with
a recently proposed geophysical hypothesis that Gondwanan
landmasses, perhaps exclusive of Africa, retained
connections well into the Late Cretaceous, much longer
than previously thought. "If so," Sampson added, "dinosaurs
and other land animals may have been able to disperse
across the vast distances between South America and
India-Madagascar via an intervening Antarctica."
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