Page 5 - Black Range Naturalist Oct 2020

M-51 (The Whirlpool Galaxy): NASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA) - October 2017
History records this as the beginning of the Oligocene epoch, but the cause of the cooling has been the subject of scientific discussion and debate for many years. It now seems it was due to a rapid drop in greenhouse gasses! (Hmmmm...We could use a little bit of that today!)
Not only did the land mass that would become the Antarctic continent begin to pull up its ice sheets—it also drifted off the land mass to the north and formed itself into its own continent during this epoch. So what was going on farther north, closer to where we call home?
Grasses evolved from among the angiosperms and grasslands began to expand. There was an increase in diversity of cold-tolerant bivalve shrimps and plankton and sea-bed borers, along with corresponding major extinctions: certain types of warmer climate snails, slugs, reptiles and amphibians. Many modern mammal groups began to appear. No direct human ancestors yet, but if you were walking around you might have encountered one of the first giant armadillos—about the size of your average Toyota Corolla!
The era also saw the rise of tiny ground sloths, which then grew to giant ground sloths, way down yonder in Patagonia, not to mention the hesperocyon, ancestor to human’s best friends, the canines, which led to our dogs, as well as early species of our favorite peccaries, the javelina, and the first eagles and hawks. Diversity sprung forth in the oceans in the form of toothed and baleen whales.
The 35 million year time-frame also witnessed the evolution of the thylacinid marsupials, dog-like creatures that carried
In March 2016, Chuck focused on M-51, the Whirlpool Galaxy. His drawing, above, and the NASA/ESA photo illustrate the differences between the disciplines of photography and illustration. What they don’t depict is the insight gained through the process of illustration.
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