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Dinosaurs living on in Orient.
Haven't seen a follow up to this tantalizing piece from dino archive.
---------- Forwarded message ----------
Date: Mon, 27 Sep 1999 20:16:41 -0400
From: "M. J. Murphy" <email@example.com>
Subject: Dinosaurs past K/T Boundary?
Found this story at www.abcnews.com.
T A L A R N, Spain, Sept. 26 ? Maybe it wasn?t a
meteor, after all, that killed off the dinosaurs.
According to one paleontologist, dinosaurs
to live for hundreds of thousands of years after that
at least in one part of China.
Many paleontologists considered the case of the
dinosaur extinction closed as of 65 million years ago,
when a large meteor slammed into Earth. Dirt and dust
tossed up by the impact blotted the sun, and the
chill shoved the dinosaurs into evolutionary oblivion.
Geologists had found the equivalent of gunpowder
burns ? a layer of the radioactive element iridium,
commonly found in meteors ? detected in rocks around
the world dated to this time.
They even found the gunshot wound - a huge crater
Mexico?s Yucatan peninsula.
Except there were a few nagging details that
quite fit the picture.
Other Pieces to the Puzzle
Many believe dinosaurs were already in decline for
millions of years before the supposed impact.
There was also another suspect ? massive volcanic
eruptions that spewed noxious gases into the air and
buried much of India in lava flows a couple of miles
over several million years. Volcanoes can also be a
Next theory: Maybe shock waves from the meteor
impact traveled through the Earth, triggering the
eruptions, which occurred almost exactly at the other
of the planet from the crater site.
That explanation doesn?t work, either. Radiometric
dating of the lava flows indicate they started long
the meteor impact. So maybe dinosaurs were just
unlucky. The volcanic eruptions triggered climactic
changes that caused their decline, and the meteor
was just the coup d?tat that finished them off.
Now Zikui Zhao of the Institute of Vertebrate
Paleoanthropology in Beijing suggests the meteor didn?t
even do that. At the First International Symposium of
Dinosaur Eggs and Babies in Talarn, Spain Saturday,
Zhao presented evidence of dinosaurs laying eggs long,
long after the meteor impact.
Fossilized Eggs Tell Story
Near the town of Nanxiong in southeastern China, Zhao
has uncovered numerous nests of fossilized dinosaur
Because sediments accumulate over time, the lower part
of a rock is generally older. And in the lower, older
he found 11 different species of eggs.
The last period of dinosaurs is known as the
Cretaceous, the period that follows is the Tertiary,
time of mass extinctions that divide the two is called
At the point in the rocks that Zhao believes
corresponds to the K/T boundary, six of the dinosaur
species disappear. Eggs of this period also show a
in levels of iridium, as well as other rare elements.
However, ?The remaining five species overstep the
boundary and survive,? Zhao says. Indeed, he finds eggs
well above the K/T boundary, suggesting that dinosaurs
lived for several hundred thousand years longer than
Questions Arise on Dating
Other scientists attending the symposium questioned his
dating. ?It is not the K/T boundary,? says Nieves
Lopez-Martinez of Universidad Complutense in Madrid,
Spain. The extinctions and iridium spike, she says,
from an earlier period of climactic change and possibly
volcanic eruptions, about 71 million years ago, which
has detected in rocks in Spain, ?not only here, but
other places in the world.?
?He definitely has an anomaly,? says University of
Colorado researcher Emily Bray, but she adds, ?I think
his boundary is too low.?
Others were also skeptical, because the rocks
surrounding the Nanxiong eggs did not show a rise in
Zhao counters that his data also shows the
smaller iridium spike and that rivers and rainfall
the iridium over millions of years.
The data also argues against the
meteor-killed-all-the-dinosaurs scenario, Zhao says.
Iridium levels jumped up in three separate spikes near
K/T boundary, something that could not be caused by a
single meteor impact.
Almost half of the eggs near the boundary show
defects in their microscopic structure, which Zhao
attributes to the high levels of the iridium and other
elements. And those may be the true dinosaur killers.
?The cause may have been environmental poisoning
and adverse changes in climate,? Zhao says, and he
to the massive volcanic eruptions in India as the
If Zhao?s dating of his eggs proves correct,
paleontologists will have to reopen their
what killed the dinosaurs.
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