Cartilage cells, chromosomes and DNA preserved in 75 million-year-old baby duck-billed dinosaur

This study is lead by Dr. Alida Bailleul (Institute of Vertebrate Paleontology and Paleoanthropology, the Chinese Academy of Sciences) and Dr. Mary Schweitzer (North Carolina State University, NC Museum of Natural Sciences, Lund University and Museum of the Rockies). Microscopic analyses of skull fragments from these nestling dinosaurs were conducted by Alida Bailleul at the Museum of the Rockies. In one fragment she noticed some exquisitely preserved cells within preserved calcified cartilage tissues on the edges of a bone. Two cartilage cells were still linked together by an intercellular bridge, morphologically consistent with the end of cell division (see left image below). Internally, dark material resembling a cell nucleus was also visible. One cartilage cell preserved dark elongated structures morphologically consistent with chromosomes (center image below). "I couldn't believe it, my heart almost stopped beating," Bailleul says.