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Lentodinella danica
From Fensome et al., 2019:
Lentodinella danica Kienel, 1994, p.54–55, pl.14, figs.1–15; pl.15, figs.1–8. Holotype: Kienel, 1994, pl.14, figs.1–3. Age:
Danian.
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Original description: [Kienel, 1994] (translated from German):
Lentodinella danica n. sp.
(Plates 14/1-15; Plate 15/1-8)
Holotype: Cyst ny 10/64, SEM 919/117-119.
Dimensions: 33 pm, cyst height (apical-antapical) 18 μm, archaeopyle diameter 7 μm, wall thickness: inner wall 1.2 μm at the archaeopyle, outer wall 1 μm.
Locus typicus: Profile from Nye K10v, North Jutland, Denmark.
Stratum typicum: Bryozoan Limestone, Dan.
Derivatio nominis: danica, after the massive occurrence in Dan.
Species diagnosis: See genus diagnosis with the addition: The inner wall is composed of two interlocking layers of hourglass-shaped crystals. The outer wall consists of long-stalked, roof-tile-like crystals in a dextral spiral arrangement.
Diagnosis: See diagnosis of genus with the addition: The inner wall is built up from two interlocking layers of hourglass-shaped crystals. The outer wall consists of long-cauliform, dextrally imbricating crystals.
Repository: Institute of Paleontology, Free University of Berlin.
Material: 7 cysts from the uppermost Maastrichtian of Kjolby Gaard, 134 cysts from the Nye Klov Dan, 165 cysts from the Kjolby Gaard Dan, 42 cysts from the Vokslev Dan, 44 cysts from the Stevns Klint Dan, 55 cysts from the Bulbjerg Dan, and 1 cyst from the Nennhausen Dan.
Description: The cysts reach horizontal diameters between 23 and 48 μm. Cyst heights of 15–30 μm have been measured. The height/width ratio is sometimes close to 1:1 (Plate 14/4). However, some cysts are extremely flat, with ratios around 1:1.5. The archaeopyles have diameters between 6 and 9 pm, depending on their overall size, and exhibit a bulging marginal structure. The operculi observed in some specimens (Plate 15/3,7) overlap slightly and are slightly notched at two opposite points.
In the fully mineralized state, the cysts are lens-shaped, and the transition from the central body, which encloses the endocoel, to the paracingulum is gradual. However, the outer wall is often missing or present only in relict specimens. In this case, the central body and the paracingulum, on which the outer wall is still preserved in almost all specimens, are sharply demarcated from each other (Plate 14/2).
Primarily, the wall is double-layered. The inner wall, with a thickness of around 1.2 μm, consists of two layers of primarily hourglass-shaped crystals that interlock like a zipper (Plates 14/8, 14, 15). However, this skeletal crystal structure is in most cases unrecognizable due to neomorphism (Plates 14/6, 9, 11-13). The crystals then exhibit a plate-like habit. From the apical view, an arrangement in radial rows is visible in centrally delaminated forms (Plates 14/1-3, 6), while antapically, at least in the central region, an arrangement in subparallel rows is evident (Plates 14/7-8). The outer wall is composed of columnar, dextrally spirally arranged crystals, at the base of which the crystal rods typical of the pithonelloid outer wall can still be seen (Plates 14/11, 12). In some specimens, the outer wall is still covered by a plate-like overgrowth. In the cingulum region, a distinction can also be made between an inner and an outer stem-spiral wall. The inner wall of the central body continues distally in the form of very coarse crystals of the same habit, which overlap each other dextrally.
One of the observed specimens shows similarities in external form to Tetratropis WILLEMS, 1990 (Plate 15/3). In lateral view, three to four keels parallel to the cingulum are vaguely visible. However, the wall structure corresponds to that of Lentodinella, and the diameter, at 32.5 μm, is also more in line with its size range.
Lentodinella danica Kienel, 1994, p.54–55, pl.14, figs.1–15; pl.15, figs.1–8. Holotype: Kienel, 1994, pl.14, figs.1–3. Age:
Danian.
---------------------------------------------------------------------------------------------------
Original description: [Kienel, 1994] (translated from German):
Lentodinella danica n. sp.
(Plates 14/1-15; Plate 15/1-8)
Holotype: Cyst ny 10/64, SEM 919/117-119.
Dimensions: 33 pm, cyst height (apical-antapical) 18 μm, archaeopyle diameter 7 μm, wall thickness: inner wall 1.2 μm at the archaeopyle, outer wall 1 μm.
Locus typicus: Profile from Nye K10v, North Jutland, Denmark.
Stratum typicum: Bryozoan Limestone, Dan.
Derivatio nominis: danica, after the massive occurrence in Dan.
Species diagnosis: See genus diagnosis with the addition: The inner wall is composed of two interlocking layers of hourglass-shaped crystals. The outer wall consists of long-stalked, roof-tile-like crystals in a dextral spiral arrangement.
Diagnosis: See diagnosis of genus with the addition: The inner wall is built up from two interlocking layers of hourglass-shaped crystals. The outer wall consists of long-cauliform, dextrally imbricating crystals.
Repository: Institute of Paleontology, Free University of Berlin.
Material: 7 cysts from the uppermost Maastrichtian of Kjolby Gaard, 134 cysts from the Nye Klov Dan, 165 cysts from the Kjolby Gaard Dan, 42 cysts from the Vokslev Dan, 44 cysts from the Stevns Klint Dan, 55 cysts from the Bulbjerg Dan, and 1 cyst from the Nennhausen Dan.
Description: The cysts reach horizontal diameters between 23 and 48 μm. Cyst heights of 15–30 μm have been measured. The height/width ratio is sometimes close to 1:1 (Plate 14/4). However, some cysts are extremely flat, with ratios around 1:1.5. The archaeopyles have diameters between 6 and 9 pm, depending on their overall size, and exhibit a bulging marginal structure. The operculi observed in some specimens (Plate 15/3,7) overlap slightly and are slightly notched at two opposite points.
In the fully mineralized state, the cysts are lens-shaped, and the transition from the central body, which encloses the endocoel, to the paracingulum is gradual. However, the outer wall is often missing or present only in relict specimens. In this case, the central body and the paracingulum, on which the outer wall is still preserved in almost all specimens, are sharply demarcated from each other (Plate 14/2).
Primarily, the wall is double-layered. The inner wall, with a thickness of around 1.2 μm, consists of two layers of primarily hourglass-shaped crystals that interlock like a zipper (Plates 14/8, 14, 15). However, this skeletal crystal structure is in most cases unrecognizable due to neomorphism (Plates 14/6, 9, 11-13). The crystals then exhibit a plate-like habit. From the apical view, an arrangement in radial rows is visible in centrally delaminated forms (Plates 14/1-3, 6), while antapically, at least in the central region, an arrangement in subparallel rows is evident (Plates 14/7-8). The outer wall is composed of columnar, dextrally spirally arranged crystals, at the base of which the crystal rods typical of the pithonelloid outer wall can still be seen (Plates 14/11, 12). In some specimens, the outer wall is still covered by a plate-like overgrowth. In the cingulum region, a distinction can also be made between an inner and an outer stem-spiral wall. The inner wall of the central body continues distally in the form of very coarse crystals of the same habit, which overlap each other dextrally.
One of the observed specimens shows similarities in external form to Tetratropis WILLEMS, 1990 (Plate 15/3). In lateral view, three to four keels parallel to the cingulum are vaguely visible. However, the wall structure corresponds to that of Lentodinella, and the diameter, at 32.5 μm, is also more in line with its size range.