Logan is a name with Irish origins. The meaning of the name Logan is from the hollow. Common nicknames for Logan include Loag and Lo. Famous Loganâs include athletes Logan Bailly, Logan Coutre, Logan Kensing, and Logan Mankins.
During the Cambrian explosion, the atmospheric oxygen levels increased by up to 10 percent, and prior to that time the living creatures roaming the Earth were typically small, simple and often single-celled.
Life in the Ordovician witnessed an evolutionary radiation that was comparable to the Cambrian explosion that occurred in the previous Cambrian period around 530 to 520 million years ago and caused the appearance of most modern phyla (though less well known then the Cambrian explosion).