Enough with the Guitar Hero already! Do something completely different this weekend go on the Paleontology Field Trip presented by the Houston Museum of Natural Science. After a quick refresher on geology and the Texas Eocene ecosystem with HMNS experts/guides, youll be ready to dig in. Your dig site is Whisky Bridge, an area especially rich with fossils. Chances are youll find plenty of 50-million-year-old shells, fishbones and maybe even a shark tooth or two. 9 a.m. One Hermann Circle Drive, in Hermann Park. For information, call 713-639-4678 or visit www.hmns.org. $12 to $28.