December 18th on the Cosmic Calendar: Trilobites and Orthocones rule the Earth!
Trilobites are among the most successful creatures this planet has ever seen. There were at least 17,000 species of trilobites. They were predators, prey, scavengers, and filter feeders. Extinct 250 million years ago, they lived for 270 million years before that. By comparison we’ve only been here for between 130,000 and 200,000 years. Trilobites were the shiz-nit.
If it was swimming and not a trilobite, it was probably an orthocone. Orthocones are related to modern octopus, cuttlefish, and squid. Jet propelled with tentacles. The main difference is that they grew huge, conical shells. They could be as small as 1 inch, or as large as 36 feet! The Giant Orthocones were the top predators of the Ordovician and Silurian periods.
All of this is still part of the Cambrian explosion btw.
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!