Placoseris poculum (Fromentel, 1857)

Löser, Hannes, Nieto, Luis M., Castro, José Manuel & Reolid, Matías, 2019, A Lower Valanginian coral fauna from the South Iberian Palaeomargin (Internal Prebetic, SE Spain), Palaeontologia Electronica (a 06) 24 (1), pp. 1-57 : 23-24

Placoseris poculum (Fromentel, 1857)

Figure 25

v* 1857 Trochoseris poculum Fromentel , p. 18, pl. 1, figs. 5, 6

v 1863b Leptophyllia poculum ; Fromentel, p. 304, pl. 48, fig. 1

vp 1989 Acrosmilia patellata (Michelin 1845) ; Löser, p. 131, text-fig. 34, pl. 26, fig. 1

vp 1994? Acrosmilia sp. ; Löser, p. 30, text-fig. 19- 21, pl. 10, fig. 6

v 2014 Acrosmilia patella (de Fromentel, 1863) ; Löser, p. 35, fig. 5f

Material. MGB 83260; 1 thin section.

Dimensions. (83260) c, 2.3 x 16.1 mm; s, 143.

Remarks. In the previous literature, the genus Placoseris was considered synonymous with Acros-

LÖSER ET AL.: SPANISH VALANGINIAN CORALS milia Orbigny, 1849. Acrosmilia is a conceptual genus; the type specimen of the type species is available but so poorly preserved that important diagnostic features, such as the presence or absence of pennulae, cannot be observed. It is therefore recommended to re-establish the use of the genus Leptophyllia that is currently considered a junior synonym of Acrosmilia . The type material of the type species of Leptophyllia is better preserved and moreover, it is easier to obtain topotypical material. The study of type specimens and topotypical material has shown that Leptophyllia is more related to the mainly Late Cretaceous family Synastraeidae and restricted to the Late Cretaceous, whereas Placoseris belongs to the Jurassic to mainly Lower Cretaceous family Latomeandridae . Leptophyllia has thicker and less perforate septa whereas in Placoseris the septa are thinner and more perforate at the inner margin. Moreover, the septa are often connected to each other in the latter, a characteristic that is less common in Leptophyllia (see Löser et al., 2019 for details).

Occurrence. Hauterivian of France (Haute-Marne) Saint Dizier ( MNHN nn). Lower Hauterivian (Radiatus Zone) of France ( Haute-Marne ) Saint Dizier. Lower Cenomanian ( Mantelli Zone ) of Germany ( Nordrhein / Westfalen ) Mülheim / Ruhr , Kassenberg ( BSPG 2003 XX 1079 ) . Lower Cenomanian ( Dixoni Zone ) of Spain (Cantabria, Santander) Cobreces, Luaña playa ( BSPG 2007 V 372) . Middle Cenomanian of Germany (Bayern) Rossstein-Almen ( LFU 8336 SG015155#1) . Upper Cenomanian (Plenus Zone) of Germany (Sachsen) Dresden-Plauen , Ratssteinbruch , southern quarry. Latest Cenomanian ( Juddi Zone ) of France ( Aude ) Les Corbières , Sougraigne , Prat-Périé ( BSPG 2011 XXVI 17 ) .

Figures

FIGURE 25. Placoseris poculum (Fromentel, 1857), MGB 83260. 1: transversal thin section. 2: transversal thin sec- tion, detail. Scale 1 mm.