Mennerius sp. A

Ovechkina, Maria N., Jordan, Richard W. & Mostovski, Mike B., 2017, On the validity, synonymy and distribution of some Lapideacassaceae (Haptophyta), Phytotaxa 308 (1), pp. 111-111 : 111

Mennerius sp. A cf. M. bispinosus (Perch-Nielsen in Perch-Nielsen & Franz, 1977) ( Figure 1C )

Lapideacassis cf. L. bispinosa : Burnett 1998: 191, pl. 6.12, figs 3, 4.

Mennerius cornuta Matveev, 2015: 34 , fig. 2:13a [invalid combination, nec Mennerius cornutus ( Forchheimer & Stradner, 1973) ]. Material:—Campanian; Hulyanka [47.40°N 29.39°E], Odessa Region, Ukraine (after Matveev (2015)).

Description:—Proximal tier short, distal tier high, possibly with perforations. Apical cone conical; two apical spines, one axial and one pointing at ≤30° angle, apical spines longer then body and apical cone combined.

Note:—Perch-Nielsen ( Perch-Nielsen & Franz 1977) described Scampanella bispinosa from several specimens found in the Palaeocene and Eocene sediments of the São Paolo Plateau, having made a reservation that the Early Palaeocene material might have been reworked from the Cretaceous. Specimens from the Coniacian of the East Indian Ocean identified by Burnett (1998: 191, pl. 6.12, figs 3, 4) as Lapideacassis cf. L. bispinosa and those from the Campanian of the Ukraine identified by Matveev (2015: fig. 2:13a) as Mennerius cornuta differ from the Palaeogene individuals in the relative orientation of the apical spines, which are positioned at an angle much less than 45° between them. One may tentatively assume that the Cretaceous forms represent a new species, whose formal description should, however, be postponed until further material is available.

Figures

FIGURE 1. Some Late Cretaceous representatives of the genus Mennerius. A. M. longus, Turonian, Ukraine; 48a, holotype. B. M. morosus, Turonian, Ukraine; 49a, holotype. C. Mennerius sp. A cf. M. bispinosus, Campanian, Ukraine. D. Mennerius sp. B cf. M. bispinosus, Lower Maastrichtian, Russia. E. M. cornutus, Lower Maastrichtian, Russia. F. Mennerius sp. A., Cenomanian, Israel. Scale bars 5 μm. (Figures 1A, 1B after Luljeva (1967); Figure 1C after Matveev (2015); Figures 1D–F, crossed nicols)