Figure 1—figure supplement 1. Phase contrast images of species sequenced in this study. ; All scale bars are 5 µm. (a) Acanthoeca spectabilis, a nudiform loricate. (b) Choanoeca perplexa, a thecate craspedid. (c) Codosiga hollandica, a naked stalked craspedid. (d) Diaphanoeca grandis, a tectiform loricate. (e) Didymoeca costata, a tectiform loricate. (f) Hartaetosiga balthica, a naked stalked craspedid. (g) Hartaetosiga gracilis, a naked stalked craspedid; the image shows a colony of cells attached to the same stalk. (h) Helgoeca nana, a nudiform loricate. (i) Microstomoeca roanoka, a thecate craspedid. (j) Mylnosiga fluctuans, a naked craspedid. (k) Salpingoeca dolichothecata, a thecate craspedid. (l) Salpingoeca helianthica, a thecate craspedid. (m) Salpingoeca infusionum, a thecate craspedid. (n) Salpingoeca kvevrii, a thecate craspedid. (o) Salpingoeca macrocollata, a thecate craspedid. (p) Salpingoeca punica, a thecate craspedid; p’ represents a live cell within its theca, and p’’ an empty theca. (q) Salpingoeca urceolata, a thecate craspedid; q’ represents a live cell within its theca, and q’’ a group of empty thecae joined at the bases of their stalks. (r) Savillea parva, a nudiform loricate. (s) Stephanoeca diplocostata, a tectiform loricate. See (Leadbeater, 2015; Richter and Nitsche, 2016) for descriptions of choanoflagellate groups and their extracellular structures.