Brigham Young University's 150-million-year-old dinosaur egg could very possibly contain the earliest-known fossilized embryo, one of the country's leading fossil egg experts says.

Karl F. Hirsch spent the past few days at BYU studying and researching the egg, found last fall at the Cleveland-Lloyd Quarry near Price and one of only two dinosaur eggs believed to be from the Jurassic period and discovered in the earth's northern hemisphere.Officials of BYU's Earth Science Museum hope that a small form revealed by CAT scans and image-enhancing inside the egg is that of an early-stage embryo, possibly only 3 or 4 days old.

Hirsch, hesitant to actually confirm that the egg contains an embryo, is careful in commenting on whether an embryo is present. "I'd hate to say it positively if I can't prove it, but it looks like it." Research "points to an embryo the odds are very good,"

Despite having no scholarly degrees or any certified academic training, Hirsch became a self-taught expert in fossilized eggs after a 1976 discovery of such an egg in Nebraska sparked a specialized interest and subsequent studies in paleontology, paleogeology and other sciences. He has published more than a dozen scholarly papers and works with the University of Colorado.

One of the few fossil egg experts in in the world, Hirsch has developed an extensive data base of information by employing the scanning-electron and polarizing-light microscopes to give complementary details on egg features and characteristics.

His BYU visit also allowed an exchange of ideas and hypotheses concerning the egg with museum personnel, including director Wade Miller.

How the egg became embedded in what Miller and others believe to be a trap-like bog millions of years ago is unknown. It may have been washed in from a nearby nesting area or carried in the reproductive tract of a female dinosaur. Hirsch said the latter would explain the egg's visible fold or crease, with the shell of an egg carried internally still pliable enough to bend without fracturing, as would a more rigid eggshell.

A return trip to the Cleveland-Lloyd Quarry is being planned for next month, with the hope that additional searching may reveal more egg fragments, perhaps other eggs, or maybe even pelvic bones of the mother dinosaur. The latter might help identify the type of dinosaur in the egg.