Re: RAJASAURUS

["fam jansma" <fam.jansma@tiscali.nl>]

>From the website:

A new species of dinosaur was announced by Indian and American scientists
today: a 30-foot (9-meter), horned carnivore that hunted other dinosaurs 65
million years ago.

A reconstruction of the dinosaur's skull (see photo gallery) may shed light
on how the continents drifted into their present positions and what might
have caused the extinction of the dinosaurs.

When paleontologists Paul Sereno and Jeff Wilson arrived in India in 2001 to
study a mixed collection of dinosaur bones gathered by Indian scientists 18
years earlier, they found the bones spread out on an office floor.

Sifting through the collection, they separated out the bones of a theropod,
or meat-eating dinosaur. When they found the center part of a skull, they
recognized a horn resembling those of dinosaurs found in Madagascar. Their
search continued, yielding a left hip, then a right hip, then a sacrum.

Sereno and Wilson consulted detailed, hand-drawn maps drafted by their
Indian counterparts and discovered the bones had been buried next to each
other, as if they had been connected.

"There was a Eureka! moment when we realized we had a partial skeleton of an
undiscovered species," said Sereno, a paleontology professor at the
University of Chicago and a National Geographic Explorer-in-Residence.

65-Million-Year-Old Bones

The bones were collected in 1983 by Suresh Srivastava of the Geological
Survey of India (GSI) and Ashok Sahni, a paleontologist at Panjab
University, during a search for dinosaur eggs and nests.

Srivastava drew a detailed map to document the position of the fossil bones
as they lay in the field. The scientists then stored the 65-million-year-old
bones at a GSI office, where they stayed until Sereno and Wilson arrived.

Working with Indian experts, Wilson and Sereno reconstructed the skull of
the new species, a stocky, 30-foot-long (9-meter-long) carnivore named
Rajasaurus Narmadensis, which means "regal dinosaur from the Narmada," the
river region in western India where the bones were found. The project was
supported in part by the National Geographic Society.

"We knew of fragments and bones [in India]," said Sereno, who has discovered
new dinosaur species on five continents. "But this skull reconstruction
offers the first glimpse into the lost world of the Indian dinosaur."

There were already two Jurassic dinosaur skeletons mounted in India.
Neither, however, represents a single skeleton, but is instead based on
composites of isolated bones.

"We know that there were carnivorous and herbivorous dinosaurs in India
through individual bones, but we really don't know just how they looked
because no two bones can be reliably said to belong to one individual," said
Wilson, who is of the University of Michigan. "Rajasaurus is important
because it represents a partial skeleton and preserves many details that
clue us into its evolutionary relationships."

The reconstructed skull is missing some parts, but it has the most important
pieces: the jaws and the brain case. Between 25 and 30 feet (7.6 and 9
meters) long, the Rajasaurus was heavy and strong, and walked on two legs.

"There are several anatomical details that make Rajasaurus a new species,"
said Wilson. "Perhaps the most striking is the horn it bears on its head.
The horn was probably rather subtle. It may have been low and rounded."

A Carnivorous Family

The carnivorous Rajasaurus, which lived in the Cretaceous Period at the end
of the dinosaur age, preyed on long-necked titanosaur sauropods, herbivorous
dinosaurs that also roamed the Narmada region. Bones from both dinosaurs
were found together.

Indian paleontologists recently found coprolites (fossilized dung) that
provide additional clues to the diet of those Titanosaurs.

"Large theropod eggs have also been described by our group from the area
where the skeleton of Rajasaurus has been recovered, but it's difficult to
relate the theropod eggs specifically to Rajasaurus," said Sahni.

The scientists believe the Rajasaurus is related to a family of large
carnivorous dinosaurs, most of which had horns, that roamed the southern
hemisphere land masses of present Madagascar, Africa, and South America.

"People don't realize dinosaurs are the only large-bodied animal that lived,
evolved, and died at a time when all continents were united," said Sereno.

Continental Drift

The Rajasaurus was likely like its contemporary, Tyrannosaurus rex,-one of
the last species to live before a catastrophe occurred some 65 million years
ago.

What exactly caused the death of the dinosaurs is a matter of great debate.
But the burial site of the bones found in India could provide a clue.

"The sediments in which these dinosaurs were found are closely associated
with one of the biggest volcanic activities recorded in the last 500 million
years on planet Earth," said Sahni.

As much as a third of India's land mass is covered with lava. That makes it
particularly difficult to find dinosaur bones. The task is made even more
difficult because India is so heavily populated.

"The best place for a paleontologist to work is an empty desert," said
Sereno.

Dinosaur discoveries could also help researchers improve their relatively
scant knowledge of how India separated from Africa, Madagascar, Australia,
and Antarctica and later impacted Asia to form the Himalaya.

"The details of the timing and route of India's northward migration are not
well resolved," said Wilson. "Dinosaurs are good organisms to study the
effects of continental drift because they cover continent-scale distances.
That is, they seem to record connections between continents fairly well."
The new species will be described in the August issue of the Contributions
of the Museum of Paleontology of the University of Michigan. Casts of the
dinosaur's skull will be donated by the team to Panjab University and the
Geological Survey of India.

Well done Sereno! :)

I don't know how much of the skull is actually preserved, but the maxilla
does show some resemblance to one figured in Chure's thesis about the Indian
theropods. Perhaps when this animal is completely described, it might help
out with the mess in the Lameta formation and of course the Indosaurus vs.
Indosuchus mess.

And again Todd, nice art!

Rutger Jansma



----- Original Message -----
From: <darren.naish@port.ac.uk>
To: <dinosaur@usc.edu>
Sent: Wednesday, August 13, 2003 1:27 PM
Subject: RAJASAURUS


> I haven't seen anyone on-line yet mention _Rajasaurus
> narmadensis_, a new Indian abelisaur described by Sereno,
> Wilson et al. There's a story about it (with artwork by Todd
> Marshall) on the NG website. Don't know if the actual paper
> is out yet though - the article says this is due to appear in the
> August edition of _Contributions of the Museum of
> Paleontology of the University of Michigan_. Judging from
> the comments and Todd's restoration, _Rajasaurus_ appears
> to be related to carnotaurines, if not a member of that clade.
>
> http://news.nationalgeographic.com/news/2003/08/0812_03
> 0812_indiadinosaur.html
>
> Oh, and well done Todd!
>
> --
> Darren Naish
> School of Earth & Environmental Sciences
> University of Portsmouth UK, PO1 3QL
>
> email: darren.naish@port.ac.uk
> tel: 023 92846045
>
>
>