In multicellular organisms, the shape of the cell helps determine its function. For example, red blood cells are donut-shaped to easily exchange oxygen and freely pass through narrow blood vessels while nerve cells are long so when connected to other nerve cells they can span long distances in the organism
The remains of fossils give scientists clues as to what the world may have been like a long tome ago. If fish fossils are found on the side of a mountain, there may have been a lake there. If a skeleton is found, they can decide what creature it was.
Https://s-media-cache-ak0.pinimg.com/564x/5f/38/fc/5f38fc3ce20c9b6deb0613f73c82e03a.jpg
Here is a image. Hope this helps :)
