Ordovicain Period Script

A: When did the Ordovician period start?

B: It started 488mya and ended 443mya in the Paleozioc era.

A: Where was most of the life found?

B: Life in the oceans was thriving, and by the end of the period life started to move to land.

A: What was life on land like?

B: There were the first primitive plants, and horseshoe crabs went to land to spawn. The climate was also warm and wet.  There was a lot of volcanic activity and co2 levels were 14-16x higher than today.

A: Where were the continents?
B: Africa, South America, Antarctica, and Australia formed the super continent of Gondwana. North America made up the land mass of Laurentia. The continents were also drifting south. There were lots of tropical cyclones.

A: What other things were happening on land?

B: All major tectonic plates were in motion and Taconic orgoeny (or mountain building) occurred. This created the appalacian mountains. Limestone and dolomite were the dominate rocks. The sandstone present in this period resisted erosion and now forms the top of the appalacian mountains.

A: What was going on underwater?

B: Marine life flourished in the vast seas which were 1,970 feet above what sea level is today. The waters were warm, and the typical creatures that lived underwater were nantiloids, conodonts, fish, bryozoans, and sea lilies. Some fossils today from the ordivician period look like modern day horseshoe crabs. The fossils found from this period are from the cryptolithus and valcouroceras organisms.

A: What were all those animals like?

B: Nantiloids were squid like creatures, conodonts were eel like, bryozoans were organisms that made coral like structures, the fish looked like modern  day lamprey eels and hagfish, sea lilies looked like sea stars. Mollusks were abundant.

A: Wow, a lot was going on, what happened at the end of the period?

B: The second largest mass extinction happened. This happened when the supercontinent Gondwana started freezing and caused a 20 million year ice age. Life rich seas shrank away and half of all marine species died.