How does a shark’s tooth end up on a trail more than 60 miles from the beach? For the eagle-eyed visitor hiking the new 1.5-mile Preserve Trail, that question might lurk as they look down at the rocks which make up the trail leading from the Entrance Gate to the Visitor Center parking lot. The story of how these fossils ended up here started millions of years ago when most of what is now Florida was underwater.
Nearly 12 millions years ago, Florida was beginning to look alot like it does today, except the shoreline was 60 miles further inland in some places. Rivers and streams flowing to the sea carried sediments, such as sand, clay and the remains of land animals, washed from the land and deposited them in the shallow lagoons and bays along ancient Florida’s coastline. Over time, the remains of marine creatures including the giant Megatooth shark (Carcharodon megalodon), which reached lengths of up to 80 feet, living in these shallow waters were also deposited on the seafloor.
This sedimentary layer continued to build up and as the sea level dropped the limestone became exposed as land. Today, this layer is between 20 to 40 feet underground and is known as the Bone Valley Formation. Fossils from these sedimentary deposits are often uncovered in the process of phosphate mining and give us a glimpse of Florida’s prehistoric past.
The gravel lining the path of our new trail was uncovered in Bone Valley at the Mosaic Company’s phosphate mine near Bartow. Millions of years of geological history can be read just by sifting through the items left behind in the sediments of the early Florida landscape.
So during your next visit to Bok Tower Gardens take a hike on the Preserve Trail and if you’re lucky enough, you’ll find a fossil from Florida’s prehistoric past. If you’ve made some interesting fossil finds on the Preserve Trail, share them with us by uploading them to our Facebook page!