Why do you think dinosaurs no longer exist?

[Guest guest]

Reggie, I posted this on my site and wanted to post it on yours as

well because of a big discussion I had with my hubby and cousin.

Why do you think dinosaurs no longer exist on this planet? What

happened to them? Did they ever exist?

WASHINGTON (AP) -- For more than a century, the study of dinosaurs

has been limited to fossilized bones. Now, researchers have

recovered 70-million-year-old soft tissue, including what may be

blood vessels and cells, from a Tyrannosaurus rex.

If scientists can isolate proteins from the material, they may be

able to learn new details of how dinosaurs lived, said lead

researcher Higby Schweitzer of North Carolina State University.

" We're doing a lot of stuff in the lab right now that looks

promising, " she said in a telephone interview.

It was recovered dinosaur DNA -- the blueprint for life -- that was

featured in the fictional recreation of the ancient animals in the

book and film " Jurassic Park. " Although that was science fiction,

Schweitzer said she was not sure if scientists would be able to

isolate dinosaur DNA fragments from the fossilized materials.

The soft tissues were recovered from the thighbone of a T. rex,

known as MOR 1125, that was found in a sandstone formation in

Montana. The dinosaur was about 18 years old when it died.

The bone was broken when it was removed from the site. Schweitzer

and her colleagues then analyzed the material inside the bone.

" The vessels and contents are similar in all respects to blood

vessels recovered from ... ostrich bone, " they reported in a paper

bring published Friday in the journal Science.

Because evidence has accumulated in recent years that modern birds

descended from dinosaurs, Schweitzer said she chose to compare the

dinosaur remains with those of an ostrich, the largest bird

available.

Hanson, a deputy editor of Science, noted that there are few

examples of soft tissues, except for leaves or petrified wood, that

are preserved as fossils, just as there are few discoveries of

insects in amber or humans and mammoths in peat or ice.

Soft tissues are rare in older finds. " That's why in a 70-million-

year-old fossil it is so interesting, " he said.

Carrano, curator of dinosaurs at the sonian's National

Museum of Natural History, said the discovery was " pretty exciting

stuff. "

" You are actually getting into the small-scale biology of the

animal, which is something we rarely get the opportunity to look

at, " said Carrano, who was not part of the research team.

In addition, he said, it is a huge opportunity to learn more about

how fossils are made, a process that is not fully understood.

A. Hengst of Purdue University said the finding " opens the

door for research into the protein structure of ancient organisms,

if nothing else. While we think that nature is conservative in how

things are built, this gives scientists an opportunity to observe

this at the chemical and cellular level. " Hengst was not part of the

research team.

R. Horner of the Museum of the Rockies at Montana State

University, said the discovery is " a fantastic specimen, " but

probably is not unique. Other researchers might find similarly

preserved soft tissues if they split open the bones in their

collections, said Horner, a co-author of the paper.

Most museums, he said, prefer to keep their specimens intact.

Schweitzer said that after removing the minerals from the specimen,

the remaining tissues were soft and transparent and could be

manipulated with instruments.

The bone matrix was stretchy and flexible and there were long

structures like blood vessels. She added that what appeared to be

individual cells were visible, but could not say if they were blood

cells.

She likened the process to placing a chicken bone in vinegar. The

minerals will dissolve, leaving the soft tissues.

The research was funded by North Carolina State University and

grants from N. Myhrvold and the National Science Foundation.