I've been trying to find plausible body plans for people who aren't human: Olaf Stapledon's "Star Maker" was a reasonably good starting place.
Then there are the creatures of the Cambrian. Some of the strangest fossils from this period come the Burgess Shale. We don't know whether critters on Earth these days don't, as a rule, have five eyes because pairs of eyes work better - or whether opabinia regalis isn't the ancestor of more creatures for reasons unrelated to it's strange-looking head.
So far, I've come up with fifteen plausible body plans - most of which are quite familiar, including the one which was used for millions of years by the bipedal dinosaurs.
But I've got the idea that I've missed something. So today I went back online and checked out a few websites that discuss the Burgess Shale. And other Cambrian fossil finds.
Western Carolina University
- 3+ billion years – life forms
- cyanobacteria (blue green algae) – very early
- changed atmosphere – generate oxygen
"The Burgess Shale Fauna"
Smithsonian / National Museum of Natural History
"Although the Cambrian Explosion is largely associated with animals having hard shells, the soft-bodied biota also diversified during this period. The Middle Cambrian Burgess Shale fauna, discovered by Charles Walcott in 1909, in British Columbia, Canada, provides a rare glimpse of Cambrian soft-bodied animals. This fauna is especially important because the fossil record is biased toward organisms having hard parts. Another famous soft-bodied occurrence is the Chengjiang Fauna, of...."
It's one page of a section on the Cambrian era. No illustrations, more useful for outlining what to look for elsewhere.
There are links to pages with text and photos, but they load in pop-up windows that won't display properly if you don't have the kind of browser and system that the Smithsonian thinks you should. (I don't.) For example, one pop-up about Hallucigenia sparsa is cut off in mid-sentence, with the best work-around I found.
Nice artwork, though.
(screen capture from the Smithsonian, used w/o permission)
The top of the pop-up displayed find: but I'd have to go in and try re-coding the source, to see what's at the bottom. That, or either adjust or replace my system.
- "The Coconut Crab: No, It's Not From a Science Fiction Movie"
(September 25, 2009)
- "Hurdia Victoria: Cambrian Supercritter of the Burgess Shale"
Apathetic Lemming of the North (March 20, 2009)