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Leptodinium italicum
Leptodinium italicum Biffi and Manum, 1988
Holotype: Biffi and Manum, 1988, pl.13, fig.4, 8, 15
Locus typicus: Scaglia Cinerea Fm., Monte Conero section, Marche Region, Italy
Stratum typicum: Oligocene Early Miocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Leptodinium italicum Biffi and Manum, 1988. According to the diagnosis, this species is proximate, ovoidal, with epicyst longer than hypocyst. Wall about 2 µm thick, composed of two layers except along the sutures. The inner appears structureless, the outer is finely spongy with a micropitted surface. Parasutural septa show a formula of 4', 6", 6c, 5(6)”’, 1p, 1"”, ps. Paraplate 6" is pentagonal, only a little smaller than 5" and with almost equal contact with 4' and 1'. Paraplate 4' appears to be clearly shorter than 1'. Archeopyle precingular. Size: length 46-60 µm, width 42-55 µm, septa 4-8 µm high.
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Original description: Biffi and Manum, 1988, p. 208
Diagnosis: Proximate cyst of ovoidal shape, epicyst a little longer than hypocyst. Wall thick, about 2.0 Ám, composed of two closely appressed layers except along sutures; the inner appears structureless, the outer finely spongy with a micropitted surface. Parasutural septa formed by the outer layer. Paratabulation formula: 4', 6'', 6c, 5(6)''', 1p, 1'''', ps. Paraplate 6'' is pentagonal, only a little smaller than 5'' and with almost equal contact with 1' and 4'. Paraplate 4' appears to be clearly shorter than 1'. Archeopyle precingular, by loss of paraplate 3''.
Dimensions: Holotype: length 60 Ám, breadth 52 Ám, septa excluded (5-6 Ám). Mean values (bracketed) and extremes (n = 15): length 46(53)60 Ám; breadth 42(47)55 Ám; septa range from 4.0 to 8.0 Ám.
Description (annotated): The parasutural septa are formed by the outer, spongy layer (periphragm) of the wall and show themselves scattered, tiny pits, but do not have the same spongy appearance as the wall itself. The wall stratification is not distinct in all specimens, probably owing to preservational differences. The septa are composed of twin layers of periphragm, which are only clearly separate proximally, where narrow parasutural pericoels are formed. In surface view, this separation shows as a parasutural pair of septa bases, tending to separate slightly more at parasutural junctions. The pericoel can also be observed in ambital view of parasutural junctions which appear like processes with hollow bases. An apical protrusion, formed by the septa , is often evident (pl. 13, fig. 12). Five postcingular paraplates are clearly expressed, however, a rudimentary parasuture may occasionally indicate the usually unexpressed 1'''. A posterior sulcal paraplate, of nearly quadrangular shape, is always present (pl. 13, fig. 10, 16).
Affinities:
Biffi and Manum, 1988, p. 208
Leptodinium italicum differs from L. membranigerum Gerlach emend. Sarjeant in having a thicker spongy wall, with a micropitted surface rather than granular; a distinct apical protrusion formed by the septa and an ovoidal shape.
Holotype: Biffi and Manum, 1988, pl.13, fig.4, 8, 15
Locus typicus: Scaglia Cinerea Fm., Monte Conero section, Marche Region, Italy
Stratum typicum: Oligocene Early Miocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Leptodinium italicum Biffi and Manum, 1988. According to the diagnosis, this species is proximate, ovoidal, with epicyst longer than hypocyst. Wall about 2 µm thick, composed of two layers except along the sutures. The inner appears structureless, the outer is finely spongy with a micropitted surface. Parasutural septa show a formula of 4', 6", 6c, 5(6)”’, 1p, 1"”, ps. Paraplate 6" is pentagonal, only a little smaller than 5" and with almost equal contact with 4' and 1'. Paraplate 4' appears to be clearly shorter than 1'. Archeopyle precingular. Size: length 46-60 µm, width 42-55 µm, septa 4-8 µm high.
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Original description: Biffi and Manum, 1988, p. 208
Diagnosis: Proximate cyst of ovoidal shape, epicyst a little longer than hypocyst. Wall thick, about 2.0 Ám, composed of two closely appressed layers except along sutures; the inner appears structureless, the outer finely spongy with a micropitted surface. Parasutural septa formed by the outer layer. Paratabulation formula: 4', 6'', 6c, 5(6)''', 1p, 1'''', ps. Paraplate 6'' is pentagonal, only a little smaller than 5'' and with almost equal contact with 1' and 4'. Paraplate 4' appears to be clearly shorter than 1'. Archeopyle precingular, by loss of paraplate 3''.
Dimensions: Holotype: length 60 Ám, breadth 52 Ám, septa excluded (5-6 Ám). Mean values (bracketed) and extremes (n = 15): length 46(53)60 Ám; breadth 42(47)55 Ám; septa range from 4.0 to 8.0 Ám.
Description (annotated): The parasutural septa are formed by the outer, spongy layer (periphragm) of the wall and show themselves scattered, tiny pits, but do not have the same spongy appearance as the wall itself. The wall stratification is not distinct in all specimens, probably owing to preservational differences. The septa are composed of twin layers of periphragm, which are only clearly separate proximally, where narrow parasutural pericoels are formed. In surface view, this separation shows as a parasutural pair of septa bases, tending to separate slightly more at parasutural junctions. The pericoel can also be observed in ambital view of parasutural junctions which appear like processes with hollow bases. An apical protrusion, formed by the septa , is often evident (pl. 13, fig. 12). Five postcingular paraplates are clearly expressed, however, a rudimentary parasuture may occasionally indicate the usually unexpressed 1'''. A posterior sulcal paraplate, of nearly quadrangular shape, is always present (pl. 13, fig. 10, 16).
Affinities:
Biffi and Manum, 1988, p. 208
Leptodinium italicum differs from L. membranigerum Gerlach emend. Sarjeant in having a thicker spongy wall, with a micropitted surface rather than granular; a distinct apical protrusion formed by the septa and an ovoidal shape.