Dinosaur nesting site yields important fossil discoveries
By MALCOLM RITTER
NEW YORK -- Scientists have struck gold in the badlands of Argentina: a
dinosaur nesting site that provided the first unequivocal embryo bones from a class
of large dinosaurs and the first definite fossil skin from any dinosaur embryo.
The square-mile site in Patagonia contains thousands of eggs. Its surface
with dark-gray fossil fragments of round, rough-textured, six-inch eggs.
``You see eggshells everywhere,'' said Luis Chiappe of the American Museum
Natural History in New York, co-leader of the expedition that found the site last
November. He and other scientists report the discovery in Thursday's issue of the
The embryo remains appeared inside fragments of eggshell. The discoveries
shed light on the early development of sauropods, a class of plant-eaters with long
necks and tails, small heads and four massive legs. The class included some of the
biggest animals ever to walk the Earth.
The eggs were laid some 70 million to 90 million years ago, apparently
titanosaurs that grew about 45 feet long -- not very big by sauropod standards.
The hatchlings might have been only about 15 inches long.
From the embryonic remains, ``we're really getting a look at what these
would have looked like to us, and felt like to touch, when they hatched,'' said
Lowell Dingus of the museum.
Experts said the remains:
Knock down a controversial suggestion that sauropods gave live birth.
Suggest that sauropods converged repeatedly in one place to lay eggs, which
would explain the massive accumulation at the site. Scientists ``never had any real
good evidence that's what dinosaurs would do,'' said Kenneth Carpenter of the
Denver Museum of Natural History, who is familiar with the report.
Show that a particular kind of large round dinosaur egg found in Africa,
China, Europe and South America is from sauropods, at least in many cases.
Though sauropods were proposed as the source of the eggs, the new find solves a
``If you're a dinosaur paleontologist, then I think it's a pretty exciting
discovery,'' Carpenter said.
Chiappe said scientists found embryonic remains within so many eggshell
that it appears some catastrophe struck the nesting ground. Floods may have
penetrated the porous shells and drowned the embryos, he said.
The fossilized embryonic bones look like tiny light brown flakes surrounded
green mudstone in eggshell fragments. No complete embryo skeletons were found,
but discovering even the collapsed bones is very unusual. Before the new find,
embryonic remains had been identified from only five species of dinosaur.