This is the journal of speculative
In April of 2018, I read an article in The Atlantic entitled “Was There a Civilization On Earth Before Humans?” In the article, NASA scientist Gavin Schmidt pinpointed the Paleocene-Eocene Thermal Maximum (PETM) 56 million years ago as the only time in recent history in which the climate suggests that there may have been another industrial civilization on Earth. He goes on to explain why he doesn’t really believe that there was one at that time, but his comments got me to thinking. Did any animal fit the profile of both big-brained and in the right time period to account for elevated CO2 emissions 56 million years ago? Did a creature that long ago
The age of Dinosaurs had gone out with a blast 10 million years before the Paleocene-Eocene Thermal Maximum (PETM) 56 million years ago and a plethora of other animals had evolved to fill the massive gap they had left. One of these creatures had a large brain, an upright posture, and had mysteriously colonized most of the Earth, crossing both oceans and seas. these were the Phorusrhacids better known as the Terror Birds. These birds had a long run in Earth’s history existing from 62 million years ago to just roughly 2 million years ago (some may have existed even longer in isolated pockets). They ranged from 3 foot up to 9 feet tall. They may have had articulated claws on the end of their wing tips (warning this is speculation), and they certainly had large brains. They were a very successful species and dominated the world for millions of years, but because their skeletons do not fossilize well we know much less about them than other species alive at the time.
What we do know is that they were wide-ranging. Probably originating in South America, they crossed the Atlantic Ocean to Africa without the ability to fly or swim great distances. They colonized parts of Europe as well which was at the time separated from Africa by the Tethys Sea and they colonized Antartica (the world was much warmer). North America, Asia, and Northern Europe were already dominated by another slightly smaller cousin to the Terror bird called Gastornithidae. Gastornithidae was similar in size and shape to the Terror Birds of the Southern hemisphere, but seem to have been more likely herbivorous. The Terror Birds however lived up to their name. They were predators and at the top of the food chain. Both species had large heads compared to their body size and were probably highly intelligent.
The Case for Intelligence
Does any of this speculation really suggest that the Terror Birds and their cousins were intelligent sapient species much less industrial? It is speculation, but this is what we do know about bird intelligence. A crow with the brain
55 million years ago the Earth was warm much warmer than today. CO2 had been pumping into the atmosphere from unknown sources. Two species of man-sized birds dominated the Earth. One in the Southern Hemisphere and the other in the Northern Hemisphere. CO2 had been released in two or more pulses lasting around 2000 years causing the PETM. Again, we are speculating, but could this have been the multiple rise and fall of civilizations pumping carbon into the atmosphere and warming the planet? We have two species that are candidates for intelligence dominating the entire globe is it possible they were not always on friendly terms? Could a conflict between two species of birds cause the rise and fall of