Dinos That Dig: Burrowing Thunder Lizards

While scouring 95-million-year-old strata in southwestern Montana, paleontologist David J. Varricchio of Montana State University in Bozeman and his colleagues stumbled upon an unusual patch of sandstone protruding from the rock that surrounded it. Soon after they began to excavate the sandstone, they found a compact mass of small bones. After teasing apart the tangle, they discovered that the remains represented an adult and two juvenile dinosaurs of a completely new species.