Smilotrochus Milne Edwards & Haime, 1851

Baron-Szabo, Rosemarie C., 2008, Dendrophylliina, Caryophylliina, Fungiina, Microsolenina, and Stylinina, Zootaxa 1952, pp. 1-244 : 80-81

Genus Smilotrochus Milne Edwards & Haime, 1851

(= Dungulia Oppenheim, 1930b , Type species. Coelosmilia milneri Gregory, 1898 , Lower Eocene of Egypt [Dungul Wells]).

Type species. Trochosmilia tuberosa Milne Edwards & Haime, 1850a (= Turbinolia compressa Morris, 1843 ), Albian of

Diagnosis. Solitary, trochoid or subturbinate, fixed. Costosepta compact, granulated laterally. Septa often fuse which can result in the appearance of pseudo-dendrophyllid arrangements or in the forming of a a pseudocolumella when septal axial ends fuse in the corallite centre. Columella absent. Septal axial ends often project and may form short or very elongate paliform structures. Wall parathecal or septothecal. Endothecal dissepiments developed, but deep in corallum.

Remarks. Gregory (1898) described the solitary species Coelosmilia milneri which, according to Gregory (1898, p. 249), is distinguished from the genus Smilotrochus only by “less simple and less crowded septa”, as well as “broader interseptal loculi”. While it remains unclear what exactly Gregory referred to as “simple” or “less simple” septa, respectively, the character of density of septa (Gregory used the term “crowded septa”, resulting in “narrower interseptal loculi”) could be considered a specific but not a generic feature. Therefore, the species Coelosmilia milneri (type species of the genus Dungulia ) is considered a species of Smilotrochus . Hence, because it is the type species of Dungulia , the latter represents a junior synonym of Smilotrochus .

In creating the genus Dungulia, Oppenheim (1930b) used non-type material to prove and establish a relation to the dendrophylliid group of eupsammiids. Because in the original description of Coelosmilia milneri, Gregory (1898) solely compared his new species with other caryophylliid species, a relation only with caryophylliid forms can be assumed. However, the presence of Trochosmilia -like septa (=rather thin, often finely granulated septa) which have the tendency to fuse was already documented by Milne Edwards & Haime (1850a) and later included in the first generic description of Smilotrochus by Milne Edwards (1857, vol. II, p. 70). Especially in taxa of this genus which have flexuous septa, as already reported for the Maastrichtian form Smilotrochus hagenowi Milne Edwards (1857 , vol. 2, p. 71), the fusion of their axial ends can result in a septal pattern that resembles the dendrophyllid type (compare specimens figured on Pl. 7, figs 5a and 6–8).