Geological Time Project - Mesozoic Age

Mesozoic Era

Welcome to the Triassic, Jurassic, and Cretacious periods 252-66 million years ago

The Evolution of Pangea

The Triassic Period

252-201 Million Years Ago

In the first Period of the Mesozoic Era, we see the earth in one giant supercontinent called Pangea. It is thought that mammals first appeared during this period.

Fossils

The Mesozoic era left behind an exciting fossil record which has helped us better understand the history of the earth.

We see records of Dinosaurs, Pterosaurs, Marine Reptiles, Cephalopods, early mammals, and a variety of plant life as some examples of the fossil record from this era.

Ichthyosaurs

Marine Reptiles

ichthyosaur fossils have been found all over the globe and were a key contributor to understanding the evolution of reptile and marine life on Earth.

The Jurassic Period

201-145 Million Years Ago

During the second period of the Mesozoic Era we see a massive change in the earth's climate and Dinosaurs completely dominated the planet. It is thought that Pangea began breaking up due to the movement of the tectonic plates during this time.

The Most Famous Reptiles

Dinosaurs appeared on earth during the Mesozoic Era.

• From the herbivores Triceratops and Stegosaurus to the carniverous T. Rex and countless other Dinosaurs, the Mesozoic era was dominated by these fascinating creatures.

How it started...

...and how it ended up.

The Mesozoic Era saw the gradual end to the Pangea supercontinent. Vavrek (2005) sums up the transition by stating “At the beginning of the era, the land masses were joined into a single supercontinent called Pangaea. However, by the end of the Mesozoic, terrestrial regions had become highly fragmented, both owing to the drifting apart of the continental plates and the extremely high sea levels that flooded and divided many regions.” (p. 1) The change from one giant land mass to multiple land masses and islands had repercussions to all life including the overall diversity of life. Vavrek (2005) addresses this change and notes that it wasn’t all negative “There is some support for continental fragmentation promoting biodiversity from several empirical studies”. (p. 4)

Vavrek. (2016). The fragmentation of Pangaea and Mesozoic terrestrial vertebrate biodiversity. Biology Letters (2005), 12(9), 20160528–. https://doi.org/10.1098/rsbl.2016.0528

The Cretaceous Period

145-66 Million Years Ago

The last period of the Mesozoic was categorized by global warming, the continued rule by Dinosaurs, and the cataclysmic end by a great Asteroid.

Mesozoic Climate

It is the Heat...and the Humidity

The Era was defined by a greenhouse climate that kept temperatures high and generally high humidity. This climate was condusive for reptile and plant to thrive.

Sellwood, & Valdes, P. J. (2006) explained how the Mesozoic Era was hotter and more humid than the Earth today. There were forests near the poles that had lots of daylight during the summer while they were covered with snow and darkness in the winter.

Sellwood, & Valdes, P. J. (2006). Mesozoic climates: General circulation models and the rock record. Sedimentary Geology, 190(1), 269–287. https://doi.org/10.1016/j.sedgeo.2006.05.013

Pterosaurs

Flying Reptiles

Closely related to the Dinosaurs were Pterosaurs such as Pteranodons and Aerodactylus. “Pterosaurs were the first vertebrates to master powered flight, and they remained the dominant flying vertebrates for over 160 million years.” (Witton, 2013, p. 1)

The End...and new Beginning

The end of the Mesozoic Era is thought to have been punctuated by a massive asteroid strike that changed the planet’s climate and led to mass extinctions.