(WWTI) – ​Commonly made in sedimentary rock, fossils can be a fun look back in time to our planet’s past. Today is National Fossil Day.

Fossils are interesting and fun to look at, but they also serve as proof of the once-living creatures that roamed the Earth. Through fossils scientists are able to learn about life from billions of years ago, with the oldest fossils being stromatolites — produced by ancient cyanobacteria – from about 3.5 billion years ago in the Early Archaean. The oldest Hominid fossil – our relative – is a jaw from homo habilis from Ethiopia dating to about 2.75 to 2.80 million years old. The first described and validly named dinosaur fossil was a lower part of a femur and probably came from a Megalosaurus, this fossil was discovered in 1676 and is unfortunately missing.

Here in New York the official state fossil is Eurypterus remipes, a sea scorpion that used to swim in shallow seas over 400 million years ago and can be found near Buffalo. However, NY has lots of fossils dating as far back to the Ordovocian, 500 to 440 million years ago.

Happy ​National Fossil Day!