Group items tagged

five-ton animal the size of a car, with a giant bony frill on its head, and you've got a fairly accurate picture of a ceratopsian dinosaur such as Triceratops.

are found only in the Late Cretaceous of North America; they are among the last of the dinosaurs (other than the birds of course).

Ceratopsians were ornithischians, or "bird-hipped" dinosaurs.

About 65 million years ago the second greatest mass extinction in Earth history occurred, resulting in the loss of the dinosaurs as well as nearly 50% of all the world’s species. Though not nearly as severe as the end-Permian mass extinction, the end-Cretaceous extinction is the most famous mass extinction in Earth history

Terrestrial plants also suffered a major extinction at this time; in some regions up to 60% of latest Cretaceous plant species were absent in the subsequent Paleocene.

The causes of the end-Cretaceous extinction are still being debated by paleontologists. Researchers agree that a major factor was an asteroid about 10 kilometers in diameter that struck what is now the Yucatán peninsula in Mexico. The effects of the impact were catastrophic, probably including global forest fires, possibly a period of cold weather due to sunlight-blocking dust and smoke, and a subsequent period of hot climate caused by the high levels of CO2 released into the atmosphere by the impact.

During the Late Cretaceous, the high levels of atmospheric carbon dioxide heated up the Earth in the same way as they do today.

presented in the collection: Cretaceous reptiles, including an impressive dinosaur co

collection

Our Fossil Plant Collection is a small but important representation of Canadian flora, particularly from the Cretaceous and Neogene (during what was formerly known as the Tertiary).

Rather than being a rapid extermination, the extinction may have been a more drawn-out transition. “In our interpretation,” Fanti says, “the end-Jurassic event was global in its effects but was mostly likely a complex sequence of local biological crises that are still poorly documented.”

if there was a mass extinction, it didn’t kill off life planetwide

Paleontologists have long debated whether or not there was a mass extinction at the end of the Jurassic period, 145 million years ago. The group that includes Machimosaurus, called the teleosaurids, is among those thought to have died out.

The climate of the Triassic era was influenced by Pangaea, its centralized position stradling the equator, and the geologic activity associated with its breakup. Generally speaking, the continents were of high elevation compared to sea level, and the sea level did not change drastically during the period. Due to the low sea level, flooding of the continents to form shallow seas did not occur. Much of the inland area was isolated from the cooling and moist effects of the ocean. The result was a globally arid and dry climate, though regions near the coast most likely experienced seasonal monsoons. There were no polar ice caps, and the temperature gradient in the north-south direction is assumed to have been more gradual than present day. The sea level rose as the rift grew between North Africa and southern Europe, resulting in the flooding of Central and South Europe; the climates of terrestrial Europe were hot and dry, as in the Permian. Overall, it appears that the climate included both arid dune environments and moist river and lake habitats with gymnosperm forests.

rming on the Americas, North Africa was being split from Europe by the spreading rift. This division of the continents advanced further westward, eventually splitting eastern North America from North Africa.