The estimated age of the earth is approximately 4.5 billion years. How long would it take one person to count 4.5 billion? Impossible, if you counted 1 number per second, eight hours a day, every day of your life it would take 428 years! Life has been on earth approximately 2.5 billion years (or 238 counting one per second), and the first vertebrate fossil (animal with a backbone and cranium) is over 500 million years old. Where does all of this information come from?

There is not one region of the planet that provides us with an entire fossil history of life on Earth. This is precisely why places like Big Bend National Park, which have an emphasis on one time frame, mean so much to the understanding of life on earth. Big Bend National Park’s geologic history is diverse, however much of the fossil record is found around the late Cretaceous and early Tertiary. There are many textbook examples of fossilized life as it was found many years ago, here today for us to discover.