In 2005, Mary Schweitzer and her team shocked the paleontological world when they reported, in the journal Science, that they had come upon soft tissue surviving deep within the fossilized thigh bone of a 68 million-year-old Tyrannosaurus rex. Similar discoveries followed. In this slide show, see what Schweitzer and her team brought to light from bones as old as 78 million years.
Growth Plate Dynamics. The growth plate is divided into several distinct regions, each populated with cartilage cells (chondrocytes) displaying characteristic behaviors.