December 27th on the Cosmic Calendar: The first birds! Birds evolved from dinosaurs in the Cretaceous. Birds and crocodiles are the only living clades of Archosauria, and the two main extinct clades of Archosauria are the dinosaurs and pterosaurs. Crocodiles predate the dinosaurs, but birds evolved from Theropod dinosaurs. Tyrannosaurus Rex was a theropod. Whenever I look at birds — geese, ducks, robins — and think these thoughts, I think “Oh how the mighty have fallen!” Still, it’s fun to look at birds and realize that they are dinosaurs. It’s also fun to think of eating dinosaur when having chicken or turkey. It’s the simple things in life, ya know? 🙂
You may remember Cosmos, the 1980 PBS series by Carl Sagan. Maybe you also recall Sagan’s “Cosmic Calendar” from the series, where in order to put the immensely vast history of the universe into a comprehensible scale, he mapped it onto a calendar year. In other words, if the entire history of the universe were one year, with the big bang in the first second of midnight on January first, and the present day on the last second of December 31st, New Year’s Eve. A project of mine this year has been to note the major events in the Cosmic Calendar, on the real calendar, on this blog!