Fossils of clams and other marine life can be found near Tulsa.
Fossils are most common in the southern and eastern portions of Oklahoma, including the Tulsa area. Fossils in this region typically formed between 500 and 85 million years ago. During much of this time period, most of present-day Oklahoma was covered by a vast but shallow inland sea. The sea floor was an ideal environment for fossils to form. Hence, many of the fossilized remains near Tulsa are those of sea creatures.
Brachiopods
Brachiopods are marine invertebrates. They look like clams; however, the two species are not close relatives. Brachiopods flourished during the Paleozoic era but about 250 million years ago most perished in a mass extinction. The fossils of brachiopods may differ in size, typically ranging from just under 1/4 inch to over 3 inches, though some brachiopod shells of up to 15 inches have been discovered.
Crinoids
Crinoids are often called sea lilies for their resemblance to underwater flowers. These aquatic invertebrates are related to sea urchins, sand dollars and starfish. The skeletons of crinoids are composed of a rock-like material known as a calcareous plate. Crinoids are one of the oldest fossil types in the world and the species is still quite common in modern oceans.
Stromatolites
Stromatolites are reef-like mounds occurring in shallow water, rendering prehistoric Oklahoma an ideal home. Now virtually extinct, stromatolites are over 3 billion years old, ranking them among the oldest fossils on earth. Though previously believed to have been created by algae, stromatolites were actually created by cyanobacteria. They are a type of prokaryote, a primitive organism with no cellular nucleus.
Common Modern Sea Creatures
Fish eventually came to populate the sea that covered the Tulsa area. Their fossilized teeth and fins have been unearthed. Coral reefs once covered the sea bed; today their fragments are scattered in rock layers. Clams and sea snails existed in ancient times and their fossils can also be found today in northeastern Oklahoma.
Plants
Northeastern Oklahoma wasn't underwater for its entire geologic history; hence, plant fossils can be found in the area. Ferns are one type of fossilized plant. Another is the root of the Lepidodendron tree, an enormous ancient species which could grow 130 feet tall. Also found in the area are Annularia radiata and stellata, which are circles of leaves growing at the joints of a now-extinct plant called Calamite.
Tags: have been, found area, million years, Tulsa area
