Back
Lejeunecysta kammae

Lejeunecysta kammae Willumsen, 2011, p.224,226, figs.11K–L.

Holotype: Willumsen, 2011, fig.K.
Age: early Paleocene.

--------------------------------------------------
Original description (Willumsen, 2011):
Lejeunecysta kammae sp. nov. (Fig. 11K, L)
Types. Holotype, Grey River, M34/f537, slide L19809/4, 16 mm, EF: E29,4 (Fig. 11K). Paratype, Grey River, same sample & slide EF: V48,4 (Fig. 11L).
Type unit and locality. Conway Formation, Grey River section, North Canterbury, New Zealand.
Etymology. After the authors deceased mother Kamma Bodil Strandberg Willumsen.

Diagnosis. Small, pentagonal, lavigate, Lejeunecysta with a truncate, reduced apical horn and two reduced antapical horns. Antapical horns have rounded tips and they are indicated by latitudinal folds. Tabulation is indicated by longitudinal distinct folds in the cingular area and mid-dorsal part of the hypocyst; the archeopyle is intercalary, type, 2a.

Description. Proximate, pentagonal, small dorsoventrally compressed peridinioid autocyst. The cyst wall is laevigate. The epi- and hypocyst are equal in size and have slightly convex to straight sides. The apical and two antapical horns are reduced; the apical horn has a truncate tip. The sulcal area is indicated by antapical latitudinal (transverse) folds that reach from the cingulum to tip of the two reduced antapical horns. Cingular area indicated by two longitudinal folds. The intercalary archeopyle, is formed by the loss of paraplate 2a; the operculum is typically in place but can be detached at the apical plate 30 contact and intercalary apical plates 1a and 3a. Total length 55(59)61 µm [3 specimens measured]. Total width 51(55)60 µm [3 specimens measured].

Remarks. Lejeunecysta kammae sp. nov. differs from L. hyalina Gerlach, 1961 by its pentagonal shape and in being half the size; from L. fallax Morgenroth, 1966 in having relatively reduced apical and antapical horns and a pentagonal shape; from Lejeunecysta spatiosa Morgenroth, 1966 by having a smooth surface and being smaller (54 X 55 µm contra 81 X 101 µm); from Lejeunecysta tenella Morgenroth, 1966 by lacking spines on the surface and having a reduced apical horn; and from Lejeunecysta cinctoria Bujak, 1980 by lacking spines on the paracingular margins and the apex. Lejeunecysta kammae has an epi- and hypocyst that are equal in size and two very reduced antapical horns, whereas Lejeunecysta convexa Matsuoka & Bujak, 1988 has well-developed antapical horns and unequal epi- and hypocysts. Furthermore, the cingulum of Lejeunecysta izerzenensis Slimani et al., 2008 is larger and has a cingulum demarcated by two denticulate septa, it lacks the longitudinal folds in the antapical area and it has a larger cyst size compared with L. kammae.

Age and distribution. Lejeunecysta kammae sp. nov. was recorded in both Mead and Branch stream sections where its FO is in the upper part of the lower Paleocene radiolarian zone RP3 (Hollis 1993, 1997, Hollis et al. 2003b) and it ranges upwards into the lowermost part of radiolarian zone RP4 (Fig. 6). It was also recorded in the Grey River section, North Canterbury.
--------------------------------------------------
Feedback/Report bug