Browsing the "Cretaceous" Category

The Cretaceous period is a division of earth’s history spanning from around 145 to 66 million years ago, and during which enormous deposits of Chalk were formed across Europe. The Cretaceous was a warm period with temperatures on average 4°C above present. Sea levels gradually rose through the Cretaceous; attaining a maximum of around 200 meters above the present level, and resulting in the formation of shallow seas as large areas of the continents became flooded. During the Cretaceous the supercontinents of Laurasia and Gondwana continued to break up; opening the Indian and Atlantic Oceans. In the oceans, teleosts, a major group of bony fish, began to flourish along with modern sharks and rays. Diatoms, a group of planktonic algae, also began to diversify. On land the first true mammals and birds evolved while dinosaurs remained dominant. A major floral revolution took place during the Cretaceous with the emergence and gradual diversification of flowering plants. The end of the Cretaceous is marked by one of the most catastrophic extinctions in earth’s history. Dinosaurs, pterosaurs, ammonites, belemnites, rudist bivalves and many groups of marine reptiles were among those wiped out. An Iridium rich layer found globally at the Cretaceous/Paleogene boundary, along with a vast impact crater in Mexico, lead many to believe that a meteor was responsible for the end Cretaceous extinction. However, massive volcanism in India, contemporaneous with the extinction, may also have been a contributing factor.

Cretaceous

Episode 108: Plesiosaurs

Published on March 1st, 2020 | by David Marshall

Plesiosaurs are some of the most easily recognisable animals in the fossil record. Simply uttering the words ‘Loch Ness Monster’ can conjure a reasonably accurate image of what they look like. Thanks to palaeoart, it’s also [&hellip... Read More


Cretaceous

Episode 105: Ferrodraco

Published on November 15th, 2019 | by Liz Martin-Silverstone

Australia has many fossils from all ages, including several dinosaurs known exclusively from this time and place. However, they are not well known for their pterosaur fossils, having only a handful of specimens, and up to [&hellip... Read More


Cretaceous

Episode 101: Organic Preservation of Dinosaur Bone

Published on July 1st, 2019 | by David Marshall

Fossilisation of organic material was long thought to result in the complete loss of original content. However in the last 20 years, several high-profile publications reported the discovery of proteins, blood vessels, blood cells and even [&hellip... Read More


Cretaceous

Episode 91: Dinosaurs of Appalachia

Published on May 24th, 2018 | by David Marshall

The Appalachian mountains, span the Eastern margin of the United States of America. They are predominantly composed of Paleozoic rocks, but Mesozoic marine sediments (formed adjacent to the Appalachian continent at the time) can be found [&hellip... Read More


Cretaceous

Episode 90: Ichthyornis

Published on May 3rd, 2018 | by Liz Martin-Silverstone

Bird evolution has long fascinated palaeontologists. Despite crown-group birds (birds giving rise to modern lineages today) evolving during the Cretaceous, there are relatively few fossils from this time, making it difficult to understand this key time [&hellip... Read More


Cretaceous

Episode 85: Ichthyosaurs

Published on January 7th, 2018 | by David Marshall

Ichthyosaurs are large marine reptiles that existed for most of the Mesozoic Era. The most familiar forms superficially represent dolphins, but some earlier ichthyosaurs were more eel like. They could attain huge proportions, with some genera [&hellip... Read More


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