Which important event in earth's history occurred during the jurassic period?
the first birds emerged on earth.
mammals were in search of food.
animals with shells emerged on earth
treelike ferns first began to grow and populate.

The first birds emerged on Earth

The Jurrasic period is a period approximately 199 – 145 million years ago.

Explanation:

During the Jurassic period (approximately 199 – 145 million years ago), the climate of earth changes from a predominantly hot and dry to a humid and tropical one. This allowed diverse vegetation to grow on the landmasses and corals to grow in the seas. This is the period that dinosaurs pervaded the lands. The first dinosaurs birds,called the pterosaurs emerged and later the Archaeopteryx, from which current birds are descendants.

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the first birds emerged on Earth.

Explanation:

Took the test.

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d

the tricuspid valve is present between right atrium and right ventricle