“If you want to become a fossil, you need to die somewhere where your bones will be rapidly buried. You then hope that the Earth moves in such a way as to bring the bones back up to the surface.”
– Louise Leakey

Pop up in the right place and you might be designated an “official” state or district fossil or dinosaur, like the species described below. Can you match each fossil or dinosaur with its state or district? (Five have an official fossil, one has an official dinosaur and one has both.).

District of Columbia
New York
West Virginia

1. The Capitalsaurus has its own holiday — Jan. 28. All that was found of this dinosaur — which lived about 110 million years ago and is thought to have walked on two legs like a Tyrannosaurus rex — is a 6-inch piece of a tailbone. The fossil was discovered by workers digging a trench for a sewer pipe in 1898. Scientists disagree on whether this small piece is enough to officially designate it a new dinosaur species. Even so, 100 years after its discovery, a bill was passed giving it official status.

2. The Belemnite is an extinct fossil mollusk that was abundant 200 million to 66 million years ago. Similar to today’s squid, it had 10 arms and a siphon that pushed out water, which moved the animal backward. Unlike modern squids, belemnites had a cone-shaped internal shell covered by a leathery skin. The shell’s gas-filled chambers helped the creature stay buoyant. The most commonly found belamnite fossil is the pencil-shaped “guard” that surrounded the shell’s chambers.

3. This fossil Ecphora gardnerae was a murex, or large meat-eating sea snail that lived in tidal waters. It bored holes through the shells of bivalves, snails, or even other Ecphora to get at the soft animals inside. It went extinct 5 million years ago.

4. The fossil Eurypterus remipes was a sea scorpion that lived 432 million to 418 million years ago, scavenging at the bottom of a shallow brackish sea. It had several spiny appendages and a pair of swimming paddles. Although euryptids are the largest arthropods known to have existed — growing up to 8.2 feet — the remipes species was only 5–8 inches long.

5. The Chesapecten jeffersonius is the fossilized form of an extinct scallop that lived 4 million to 5 million years ago on a coastal plain. Its fossil is most often found in stream valleys and on river beaches. A drawing and description of this fossil were published in 1867, making it the earliest U.S. specimen to appear in scientific literature.

6. Astrodon’s two teeth, unearthed in 1858 were among the first dinosaur discoveries in the United States. These teeth were given to a dentist who discovered a star pattern when slicing them into cross sections. Astrodon means “star tooth.” Astrodon, which lived about 112 million years ago, ate plants and is thought to be related to the Brachiosaurus.

7. The trilobite, Phacops rana, lived between 405 million and 365 million years ago, Trilobites are the first organisms on Earth known to have eyes, and Phacops rana and other closely related trilobites are known for their exceptionally large, round eyes that are positioned on top of its head much like a frog (rana is Latin for frog) that allowed the creature an almost 360-degree field of view. Trilobites had large antennae and many appendages for swimming, walking or eating. It is hard to find complete fossils because these appendages were attached to the body with organic connections that decayed. Incomplete fossils are common because a growing trilobite was thought to shed its outer skeleton as many 10–12 times in its life, and these were fossilized.

8. When Vice President Thomas Jefferson was first presented with fossilized bones from the Jefferson’s ground sloth in 1796, he took one look the claws (8–20 inches long), and called it Megalonyx, (“giant claw”). He believed the bones belonged to a species of lion that was still alive and years later asked Lewis and Clark to keep an eye out for one on their expedition. When the bones were finally identified as those of a sloth, it was named in Jefferson’s honor, Megalonyx jeffersonii. This sloth, which lived 10.3 million to 11,000 years ago, grew up to 10 feet long and weighed 1,000 pounds. It walked on all fours, but stood on its back two feet — a strong muscular tail helped it to keep its balance — while ripping down branches and leaves of trees to eat with its front claws.


1. District of Columbia
2. Delaware
3. Maryland
4. New York
5. Virginia
6. Maryland
7. Pennsylvania
8. West Virginia