Starfish first appeared in the fossil record in the Cambrian. The first known asterozoans were the Somasteroidea, which exhibit characteristics of both groups. Starfish are infrequently found as fossils, possibly because their hard skeletal components separate as the animal decays. Despite this, there are a few places where accumulations of complete skeletal structures occur, fossilized in place in Lagerstätten — so-called "starfish beds". By the late Paleozoic, the crinoids and blastoids were the predominant echinoderms, and some limestones from this period are made almost entirely from fragments from these groups. In the two major extinction events that occurred during the late
Chloroflexi (phylum) the members of the phylum Chloroflexi are monoderms, but stain mostly Gram negative. The taxon name was created in the 2001 edition of Volume 1 of Bergey's Manual of Systematic Bacteriology and is the Latin plural of the name "Chloroflexus", the name of the type genus of the phylum, a common practice. In 1987, Carl Woese, regarded as the forerunner of the molecular phylogeny revolution, divided Eubacteria into 11 divisions based on 16S ribosomal RNA (SSU) sequences and grouped the genera "Chloroflexus", "Herpetosiphon" and "Thermomicrobium" into the "Green non-sulfur bacteria and relatives", which was temporarily renamed as "Chloroflexi" in Volume