By Dane and Patrick. Early Cretaceous Epoch - from 145.5 – 127 million (Neocomian) years ago. Middle Cretaceous Epoch – from 127 – 89 million years (Gallic)

By Dane and Patrick

Early Cretaceous Epoch - from 145.5 – 127 million (Neocomian) years ago.

Middle Cretaceous Epoch – from 127 – 89 million years

(Gallic) ago.

Late Cretaceous Epoch – from 89 – 65 million years (Senonian) ago.

Overall it occurred from 145.5 – 65.5 million years ago

In between the Tertiary and Jurassic Period.The Cretaceous Period was the last period on

earth that had dinosaurs.Was named after the chalky rock from

Southeastern England, this was the first sediment studied from the cretaceous period.

At this time the breakup of Pangea into serperate continents was underway.

The super continent Pangea was still together at the start of the Mesozoic Era.

It began breaking apart in the mid Jurassic Period and was distinctly separated by the late Cretaceous Period.

Volcanic activity assisted in continental drift.

Flowering Plants (angiosperms) flourished and became very common

Hardwood began to replace the Conifers as the dominant trees of the forests.

These new plants provided fruit and nectar as a new source of food, causing great changes in all land life.

Dinosaurs continued to dominate the land but things had changed from the Jurassic Period. Large Sauropods were rare and armoured dinosaurs were becoming common.

Carnivores were more common but adapted to be smaller and more agile.

There was a mass extinction of marine and land life forms at the end of the Cretaceous Period.

Principle casualties were the dinosaurs and ammonites.

No species of land animal weighing more than 25kg survived to live in the Tertiary.

Nearing the end of the cretaceous period a 10 km diameter meteor hit the earth.

It caused 75% of the plant and animal species to disappear.

The impact of the meteor caused it to explode, ash dust and other debris spread and actually blocked out the sun for almost a year.

Land covered with forest and surrounded by shallow seas. Towards the end of the cretaceous period there was a drop in

sea level, causing land exposure on all continents, more seasonality and greater extremes between equatorial and polar temperatures.

Most land mass was at or around sea level until the mid-cretaceous

Sea levels rose, covering 1/3 of the land area

Time of high tectonic activity and volcanic activity Many mountain ranges formed at this time such as:

California’s Sierra Nevada

European Alps  Warm, subtropical climate

No polar ice

The general breakup of Pangaea into separate continents was underway

The separation of Laurasia and Gondwana was complete

Laurasia and Gondwana were 2 supercontinents as a result of the separation of Pangaea

The Cretaceous period ended 65 million years ago with the extinction of the dinosaurs, and many prehistoric life forms

This mass extinction was the second-largest in the history of the planet

The building of the Rocky Mountains has begun