What You Need to Know
It is possible that dinosaurs died out when a giant asteroid hit the earth, which
essentially vaporized every biotic thing on the surface. Only things living in
the ground survived, like mammals which dug burrows, seeds of plants, or fish,
lizards, and some species of birds (which could have evolved from
dinosaurs).
Since the dinosaurs became extinct, the climate
has cooled considerably. The Arctic and the Antarctic were ice free during the
age of the dinosaurs, but they are frozen today. Even though our world's climate
is increasing and is getting closer to the temperature that the dinosaurs once
lived in, many of our atmospheric features have changed. For example, there is
much more oxygen now than the time back then.
Why didn't reptiles re-evolve into dinosaurs?
Mammals are one of the reasons. They have occupied many of the niches that were
left vacant after the extinction of dinosaurs. Large reptiles would
become successful on islands if mammalian competition doesn't exist.
It is possible that dinosaurs died out when a giant asteroid hit the earth, which
essentially vaporized every biotic thing on the surface. Only things living in
the ground survived, like mammals which dug burrows, seeds of plants, or fish,
lizards, and some species of birds (which could have evolved from
dinosaurs).
Since the dinosaurs became extinct, the climate
has cooled considerably. The Arctic and the Antarctic were ice free during the
age of the dinosaurs, but they are frozen today. Even though our world's climate
is increasing and is getting closer to the temperature that the dinosaurs once
lived in, many of our atmospheric features have changed. For example, there is
much more oxygen now than the time back then.
Why didn't reptiles re-evolve into dinosaurs?
Mammals are one of the reasons. They have occupied many of the niches that were
left vacant after the extinction of dinosaurs. Large reptiles would
become successful on islands if mammalian competition doesn't exist.