Sharks don't have bones. They are a special type of fish known as "elasmobranchs", which translates into fish made of cartilaginous tissues. Even though sharks don't have bones, they still can fossilize. As most sharks age, they deposit calcium salts
Tumbleweeds originated in Russia and Siberia and they were brought to the United States in the 1870s, hidden among imported flax seeds. It only took 20 years for the plants to spread throughout the western United States and parts of Canada.