Streak, color, luster, crystal structure.
Answer:
Since neither reptile could have swum great distances across salt water he inferred that they once lived on a single landmass that has since split apart.
Tundras and deserts have a number of similarities such as their lack of water or how organisms that inhabit them are have special features to survive their extreme weather. Both are nearly unsustainable for human life and have just like the tundra, deserts have freezing temperatures at night.