This era of intense bombardment, known as the Ordovician impact spike, may have resulted from meteorites falling from the ring rather than flying in from space, which would explain the strange ...

Graptoloidea - Graptolites were minute individual tube-shaped animals ... In life, the rhabadosome was suspended from a "float" by a slender thread called a nema. Late Ordovician Period - The ...

like graptolites, that no longer exist. The extinction event, known as the end-Ordovician, was one of the five biggest of the past half billion years. It coincided with extreme changes in climate ...

Learn more about the time period that took place 488 to 443 million years ago. 3 min read During the Ordovician period, part of the Paleozoic era, a rich variety of marine life flourished in the ...

The digging and burrowing of prehistoric worms and other invertebrates along ocean bottoms sparked a chain of events that released oxygen into the ocean and atmosphere and helped kick-start what is ...

In this country, in Devonshire and Cornwall, the occurrence of radiolarian cherts, both of Ordovician and Carboniferous ... and this has been attempted with the Graptolites, and wit'l several ...

Skevington (1978) suggests that Ordovician graptolites may have shunned cold-water areas. The scarcity of such fossils in the Meguma may be a consequence of a near-polar setting.

The Ordovician world was a watery one in which vast oceans covered almost the entire northern hemisphere. In the south, the mega-continent of Gondwana drifted. According to the University of ...

It was responsible for the extinction of 23% of all marine animals. Some species, such as graptolite, saw a reduction as high as 70%. This mass extinction is believed to have been a combination of ...