How was the cretaceous period different from the jurassic period?
a. the jurassic period had angiosperms, while the cretaceous did not.
b. pangaea split during the jurassic period.
c. there were dinosaurs in the jurassic period, which went extinct in the cretaceous period.
d. conifers and ferns were present in the jurassic period, but not in the cretaceous period.

The Jurassic period and the cretaceous period were the periods of the Mesozoic era. The middle period of this era is the Jurassic period which is also called as the age of reptiles. When this period was ending minor mass extinction of some reptiles occurred. The Jurassic period was followed by the Cretaceous period. This period was the longest and the last period of this era. Because of the mass extinction in the Jurassic period, many of the dinosaurs present in the Jurassic period were not present in the cretaceous period.

Hence, the correct answer is 'option C - there were dinosaurs in the Jurassic period, which went extinct in the Cretaceous period'.

the trilobite is used as an index fossil for various geologic time periods as specific types of the trilobites were present in different geological time periods. they are a group of marine arthropods belonging to the class of trilobita.

explanation: