This is possible because when a star dies, it basically expands to its maximum (explodes). Therefore, the materials of the exploded star mix with the primeval hydrogen of the Universe. Later, other stars are formed out of this mixture. Thats also how the sun was formed. :)
Answer:
Using the number of amino acid differences, it would appear that the two birds are more closely related (had a common ancestor very recently), while the two fungi would have to trace their common ancestry much farther back in time (much more distantly related).
The remains of a Hadrosaur are an example of a fossil typically structures like bones shells and teeth fossilized more often then things like tissues or plant leaves.