Andie Lichtman, a paleontologist from San Francisco, top, encourages the crowd of youngsters gathered at her "Dinos Rock!" program to roar like a T. rex as she prepares to show off a dinosaur bone and fossil collection at the Pleasant Hill Library on Aug. 28. Up for the request, above, are 5-year-olds Robin Hartz of Concord, Eli Babcock of Twin Falls, Idaho, and John Franco, 4, of Martinez. Joseph Fray, 5, of Brentwood, left, is dwarfed by a leg bone of an allosaurus. Children and families were able to touch dinosaur bones and get an up-close view of dino-eggs, dino-tracks and dinosaur fossils as much as 500 million years old.
To view a slideshow of the dinosaur presentation, visit http://photos.mercurynews.com/2012/08/30/dinos-rock-rolls-through-pleasant-hill-library/.