Keichousaurus was an early reptile that lived during the Triassic Period (roughly 245-208 million years ago). They lived in beach-like environments.
The reptiles were small, between 15-30 centimeters (6-12 inches) long, and had long necks and tails. They also had five long toes on each foot, and pointed heads and sharp teeth. The reptiles' legs were evolving so they would be better suited for aquatic life. They used their tails to propel themselves and their legs to paddle in the water.
The bones in the reptiles' limbs were very large, indicating they had spent considerable time on land, probably in marshes.
It would not have been a graceful sight, as they had a difficult time swimming.
Crinoids or "sea lilies" are ancient sea creatures closely related to starfish.
Crinoids' skeletons were composed of root-like structures attached to stems composed of many disc-shaped plates called columnals. Their heads, or calyxes, were attached to the top of the stems. Crinoids' arms -- used to filter food from water -- were connected to their heads.
(China Daily August 8, 2002)
