Ventrolaminidae Weynschenk, 1950

SCHLAGINTWEIT, FELIX, YAZDI-MOGHADAM, MOHSEN & TEŠOVIĆ, BLANKA CVETKO, 2023, Upper Cretaceous Foraminifera Murgeina Apula (Luperto Sinni, 1968): A Methusalem And Cenomanian-Turonian Boundary Survivor Taxon, Acta Palaeontologica Romaniae 19 (2), pp. 25-38 : 29

?Family Ventrolaminidae Weynschenk, 1950

Remarks: Murgeina has been placed previously within an unknown family belonging to the superfamily Endothyracea Brady, 1884 ( Bilotte & Decrouez, 1979), later into the Nautiloculinidae Loeblich & Tappan, 1985 ( Loeblich & Tappan, 1987; Kaminski, 2014). The wall of this family has been defined as ‘ microgranular calcareous, agglutinated, simple and without exoskeletal or endoskeletal structures, single layered except for septa which are secondarily doubled ’ ( Loeblich & Tappan, 1985, p. 92). For the genus Murgeina, Loeblich & Tappan (1987, p. 71) described the wall as ‘ calcareous finely granular, with radial calcite forming a thickened umbonal region on both sides of the test ’. The presence of the outer thin calcite layer of the wall and also the septa has not been taken into consideration. Due to its doublelayered wall and septa, Murgeina can therefore not be placed within the Nautiloculinidae . This feature however would place Murgeina into the Ventrolaminidae Weynschenk, 1950 together with genera such as Protopeneroplis Weynschenk, 1950 ( Fig. 5 ). Such a suprageneric status had already been briefly mentioned, but not followed up, by Luperto Sinni (1999). The inclusion of the Ventrolaminidae into the order Involutinida Hohenegger & Piller, 1977 by Loeblich & Tappan (1987) is rejected herein. It is common consensus that involutinins have an aragonitic shell composition (e.g., Rigaud et al., 2013). Note that the inclusion of the Ventrolaminidae into the Endothyroidea was envisaged by Septfontaine (1978) and followed by Bilotte & Decrouez (1979) for Murgeina however leaving open the family belonging. Finally, it is worth mentioning that Nummofallotia is instead classified as a member of the family Meandropsinidae Henson, 1948 with a porcelaneous test and an umbo with radialfibrous mineralogy/appearance ( Loeblich & Tappan, 1987; Hottinger & Caus, 2009) ( Fig. 1 ).

Figures

Fig. 5 Possible post-Triassic fusulinanids Protopeneroplis striata Weynschenk (a-c), Upper Jurassic of Romania and Murgeina apula (Luperto Sinni), Upper Cretaceous (Campanian) of Croatia (d). a Axial section. Note the irregular coiling, the alternating dark and bright layers in the umbo, and the presence of an outer hyaline-calcitic layer (arrow). b-c Equatorial sections. Note the double-layered septum (s) and wall (arrow). d Slightly oblique axial section. Note the alternating dark and bright layers in the umbo (compare to P. striata in a).

Fig. 1 Nummofallotia cretacea (Schlumberger, 1900) from the Upper Cretaceous of Austria. a Equatorial section; Wegscheidgraben, Santonian Hochmoos Formation, Gosau Group (see Wagreich, 1988). b Slightly oblique axial section, same sample as a. Note the well-preserved light brownish porcelaneous wall. c Axial section showing test dissolution affecting the porcelaneous wall dissolution, while the radial fibrous umbo remains unaffected; Uppermost Maastrichtian Kambühel Limestone, Kambühel type-locality (see Tragelehn, 1996). Scale bars = 0.2 mm.