Rhizaria

Abstract

Have you ever stumbled across Ernst Haeckel's stunning 19th century art prints representing complex symmetrical forms that look like snowflakes, armored knights, or even futuristic space stations? Or maybe walking down an indo-pacific beach, you have taken a closer look at the warm sand only to realize that the 'sand' is really countless, minute earthly stars? Chances are you did not realize it, but in both cases you were looking at the skeletons of single-celled organisms belonging to Rhizaria, a large group, or 'supergroup', of eukaryotes. Various kinds of rhizarians have long been known to biologists, as evidenced by the fame and frequency with which Haeckel's illustrations have been reproduced, but the idea that these organisms are all related to one another emerged only recently. And this means that Rhizaria, as a whole, is one of the most poorly understood supergroups of eukaryotes.