Evolutionary scenario of Thecosomata.

<p>On the right is denoted a series of fossil records. The names of the four drawn fossils are indicated by asterisks. Colors grouped fossils and living species together according to their closed morphology. The dotted lines characterize the unresolved branching:. Five paleoclimatic events mentioned in the text are also indicated and correspond to Late Paleocene Thermal Maximum (LPTM), Early Eocene Climatic Optimum (EECO), Oi-1 Glaciation (Oi-1), Late Oligocene warming (LOw) and Middle Miocene disruption (MMd) that corresponded to the Langhian/Serravalian boundary. Paleontological estimates correspond to the oldest fossils record from different studies: <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059439#pone.0059439-Janssen2" target="_blank">[103]</a> for <i>Thilea</i>; and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059439#pone.0059439-Hodgkinson1" target="_blank">[44]</a> for <i>Vaginella</i> Daudin, 1800 <i>Cheilocuspidata</i> Hodgkinson, 1992, <i>Loxobidens</i> Hodgkinson, 1992 and for <i>Euchilotheca</i> Fisher, 1882. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059439#pone-0059439-t003" target="_blank">Table 3</a> for the others fossil references. The older <i>Styliola</i> and <i>Hyalocylis</i>-like fossil was represented by horizontal line on the branch.