Technological advancements during the past two decades have unearthed a greater comprehensive study of mammals that roamed the continents more than 80 million years ago. These microscopic new discoveries will be featured in a traveling exhibit called “Dinosaurs: Ancient Fossils, New Discoveries,” opening March 27 at the San Diego Natural History Museum. This exhibit will be curated by Dr. Thomas Demere, a Joshua L. Baily Jr. chair of paleontology at the museum since 1993. His research has focused on the evolutionary history and paleobiology of pinnipeds and cetaceans. “There are many new sophisticated techniques in the last 20 years, like medical scanners to look inside the mammals,” Demere said. “More paleontologists are searching for dinosaurs and to determine the many ways to analyze data. Even developing countries are supporting paleontology with training procedures. “In our area, we’ve collected the remains of dinosaurs from the [time period of] 75 million years. Armour dinos, Hadrosarus and Technosairus fossils have been located in Carlsbad, La Jolla, Point Loma and southern Orange County. They’re mostly isolated bones. Southern California’s record of dinosaurs are rather limited.” An exhibit highlight will be a 700-square-foot walkthrough diorama depicting the rich diversity of these animals in a Mesozoic forest in China — considered to be the most detailed recreation of a prehistoric environment. Visitors can stroll through a replica of time 130 million years ago and come face to face with amazing creatures, including the largest Mesozoic mammal ever uncovered, the badger-sized Repenomamus giganticus. Another highlight will be the Bambiraptor feinbergi, a well-preserved Dromaeosaur fossil that, along with several other fossils, provides evidence that dinosaurs were closely related to modern birds. This represents the most up-to-date look at how scientists are reinterpreting many of the most persistent and the puzzling mysteries of dinosaurs. It reveals what they looked like, how they behaved and how they moved, as well as the complex and hotly-debated theories of why — or even whether — they became extinct 65 million years ago. “There’s still different compelling hypotheses about what happened to the dinosaurs,” Demere said. “Including the notion that birds are closely related to dinosaurs and that we still have them flying around.” This exhibit was organized by the American Museum of Natural History, New York, in collaboration with the Houston Museum of Natural Science: the California Academy of Sciences, San Francisco; the Field Museum of Chicago; and the North Carolina Museum of Natural Sciences in Raleigh. A year ago, local museum paleontologists and construction workers excavating at the East Village construction site for the new Thomas Jefferson School of Law downtown campus discovered partly exposed 500,000-year-old fossil remains of a gray whale and what they believe to be a southern mammoth, an unprecedented find in San Diego County. These were displayed recently during a news conference at the museum. Shown were a mammoth skull with tusks, lower jaw, molar teeth, vertebrae and limb bones. Also produced were a gray whale’s 8-foot lower jaw, rostrum, vertebrae and ribs plus smaller mammals. Demere expressed the feeling that many more fossils might be beneath the city. “The dig depends on location,” he said. “Torrey Pines State Park’s erosion by the ocean has brought beautiful exposures … rocks in the sea cliffs that are 48 million years old that could contain fossils. Another would be Mission Valley’s erosion from the rock quarry. Heavy equipment has excavated into the slopes back 43 million years.” Paleontologists here lack the funds to explore, so they must rely upon building sites to come up with the surprise finds. Demere encourages them with his motto: “No hole is too deep.”