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 Named Chilesaurus diegosuarezi, it is a member of the same
dinosaur group as Tyrannosaurus rex, theropods, which includes the
largest land meat-eaters in Earth's history, but it ate only plants
with a beak and leaf-shaped teeth, scientists said on Monday.
Its skull and neck resembled those of primitive long-necked
dinosaurs, and its vertebrae those of primitive meat-eating
theropods. It had robust arms, but just two blunt fingers on each
hand. It was bipedal, but its wide, four-toed feet were unlike the
slender, three-toed feet of most theropods. And it had a bird-like
pelvis.
"Chilesaurus constitutes one of the most bizarre dinosaurs ever
found," said paleontologist Fernando Novas of the Bernardino
Rivadavia Natural Sciences Museum in Buenos Aires, calling the
creature an evolutionary "jigsaw puzzle."
 "The skeletal anatomy of Chilesaurus gathers characteristics of
different dinosaur groups, like a floor is composed of mosaics of
different shapes and colors. No other dinosaurs exhibit such a
combination or mixture of features."
Chilesaurus lived in a region crisscrossed by rivers at the Jurassic
Period's end, approximately 145 million years ago. It was relatively
small, reaching up to 10.5 feet (3.2 meters) long, although most
specimens found were more the size of a turkey.
It belongs to a previously unknown dinosaur lineage, University of
Birmingham paleontologist Martín Ezcurra said.
"The most interesting (aspect) about Chilesaurus is the story that
it tells about how evolution works," he said.
"'Convergent evolution' is a process in which two unrelated species
or groups acquire similar characteristics from living in similar
environments or having a similar behavior," like the wings of a bat
and a bird, Ezcurra added.
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"In the case of 'mosaic convergent evolution,' different parts of
the body resemble those of other unrelated species, such as in the
case of the platypus and Chilesaurus."
Most theropods were meat-eaters, although a few lineages preferred
salad over steak. Chilesaurus diegosuarezi, whose name honors the
country where it was unearthed and the 7-year-old who spotted the
first fossils, is the first known Southern Hemisphere herbivorous
theropod.
Four nearly complete skeletons and dozens of bones from other
individuals were found, making Chilesaurus one of the best
understood Jurassic Southern Hemisphere dinosaurs.
The research appears in the journal Nature.
(Editing by Ted Botha)
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