Unfortunately, there's no way to make spoilers on Sagan 4 Alpha. If these seem ludicrously large, know that the original images were much, much larger.
These were all made years ago. Some of the organisms have since been submitted, so one can use those to make a rough timeline of when I made each sketch page.
"Fermisaurs" and Fermi Grayflora

Mostly Dundis and Pukais:

Flora, Filter-Feeders and a Rejected Dundi:

Curals, Sunlogs, and More "Fermisaurs":