Fossil Facts

• Youti yuanshi age: 520 million years+

• Location of discovery: China

• Basal tetrapod age: 280 million years

• Location of discovery: Namibia

What are fossils? Where do they come from and how are they found?

Fossils are ultimately rocks. They are the PRESERVED remains, or traces of remains, of ancient organisms, but they are not the remains of the organism itself. Those preserved remains become fossils after about 10,000 years—which is a long time to survive undisturbed!

A fossil can preserve all or just part of an organism. Fossils can even come from feathers and leaves! They can be as small as microfossils, which are only visible with a microscope, and they can be as large as petrified trees or dinosaur bones—weighing several tons!

Fossils have been found all around the world, by everyday people and scientists alike. Fossils are cool because they can give glimpses today into how the world was

thousands, or sometimes even millions, of years ago and how things evolved over time.

One recent discovery is a great example of that: a newly published study talks about a rare fossil named Youti yuanshi. This fossil was found in China and dates back over 520 million years!

Youti yuanshi belongs to a group called euarthropods and gives a glimpse at one of the earliest ancestors of today’s insects, spiders and crabs. Researchers have said that the fossil is incredibly well preserved and that preservation has allowed them to get an exceptionally good look at the anatomy.

Another recent discovery also has scientists’ attention: a 9-foot-long fossilized giant basal tetrapod. Basal tetrapods were early four-legged vertebrates with fingers and toes that lived about 280 million years ago!

The fossil took more than two years to excavate and prepare for analysis. Researchers are excited about the discovery because it expands the area where these giant creatures were believed to have lived, and it allows them to better understand the evolution of land-dwelling animals. Scientists say that basal tetrapods are among the earliest ancestors of all modern animals!

The fossil will soon be on display in the Geological Museum of Namibia.