Faunal Succession Challenge

Welcome to Faunal Succession Challenge. Every time this cache is found, a competition will be triggered in my classroom. Students will need to know the science behind strata, fossils, faunal succession, and evolution. Come find this cache and challenge my students with Faunal Succesion.

So what is Faunal Succession?

For centuries, scientists believed the earth was a very young planet. The animals that exist today were thought to be the same as its inception. That belief held true for most scientists well into the 19^th century. Of course, people started coming across the fossilized bones, teeth, and claws of creatures unknown to the modern world. The first fossil descriptions go all the way back to the ancient Greeks. Over 2,000 years ago, dinosaur fossils were described in China as well. Much later, (1676) an enormous femur of an unknown dinosaur was discovered in Rural England. By the mid 1850s, new dinosaur fossils were popping up everywhere, including the United States.

One amazing example is in the state of Kansas. Kansas is about as far away from an ocean as any state in the USA. Yet in its slowly eroding sedimentary rock, there are tons of different marine species. You can easily find extinct fossils of corals, clams, fish, trilobites, ammonites, and sea turtles. Perhaps the most dramatic of Kansas fossils include the 60ft long enormous marine predator Mosasaur. So why are all the extinct sea creatures found in the middle of land-locked Kansas? In fact, Kansas (and much of central North America) was covered by an enormous interior sea called the "Western Interior Seaway." The fossils found here are a result of these dead creatures dying in the sea and being buried by sediment, which gets compacted over time. If conditions are perfect, the hard parts of these dead creatures (bones, claws, and teeth) will become fossilized. What's really happening is that water is getting into the bones, bringing minerals that replace the once living tissue. That's why they are called "Mineral Replacement Fossils."

It was once thought that perhaps these odd fossils represented a class of organisms that have migrated to undiscovered/charted areas. Explorers continued to fill in the gaps of our planet, and still these mystery fossils remained unexplained. It became clear to scientists worldwide that there were creatures that went extinct, and luckily their hard parts (bones, teeth, beaks, etc.) were left for us to find.

The amazing thing about these fossils is that they are found in the layers(strata) of sedimentary rock in an invariable vertical order. That means that the oldest fossils (stromatolites, trilobites, etc.) are always found in layers below more recent creatures (reptiles, mammals, birds etc.). For instance, the fossils of Neanderthals have never been found in the same layer as Mosasaurus, because they lived in different geological periods. This is called the "Law of Faunal Succession." This principle dates back to the late 1700s, and the work of geologist William 'Strata' Smith. Using this principle and the amazing accuracy of radiometric dating, scientists are able to date the geologic time period a fossilized organisms lived in.

The continued discovery of new fossil species has changed scientists' view of our planet. No longer is it seen as a young spinning rock, but rather an ancient constantly changing planet. Evidence for this can be found in many branches of science, including Paleontology, Continental Drift, Evolution, Meteorology, Molecular Biology, Biochemistry, Physics, dendrochronology, Volcanology, among many others.

Good Luck and Happy Caching