Living corals are found in warm shallow seas. coral fossils have been found in the sedimentary rocks of alaska. these findings suggest that:

These findings suggest that Alaska once had a tropical marine environment. These findings show that the earth climate and ocean distribution that exist now is different from that which existed millions of years ago. This is in agreement with the theory some scientists put forward which states that millions of years ago, sea level was much higher  and most of the land masses were cover with water and the climate was more evenly distributed. 

Organism, organ system, organs, tissue, cells

The answer is texture