Back
Unipontidinium aquaeductum
Unipontidinium aquaeductum (Piasecki, 1980, p.70, pl.1, figs.1-3; pl.5, figs.1-2) Wrenn, 1988, p.148.
Originally Nematosphaeropsis, subsequently Nematosphaeropsis?, thirdly Impagidinium, fourthly (and now) Unipontidinium.
Holotype: Piasecki, 1980, pl.1, figs.1-3
Originally Nematosphaeropsis, subsequently Nematosphaeropsis?, thirdly Impagidinium, fourthly (and now) Unipontidinium.
Age: mid Barremian (Middle Miocene?)
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Unipontidinium aquaeductum (Piasecki, 1980) Wrenn, 1988. According to Wrenn (1988, p.148), Unipontidinium aquaeductum has two wall layers, with the central body giving rise to processes (gonal, or gonal and intergonal) that are joined at their distal terminations by single parasutural trabeculae, processes may or may not be joined proximally by parasutural features on the central body. Paratabulation is 3-4', 6", 6c, 5-6"', 1p, 1"". The archeopyle is precingular resulting from the loss of plate 3". Size: length 38-47 µm, width 24-36 µm.
--------------------------------------------------
Original description: Piasecki, 1980, p.70: Nematosphaeropsis aquaducta
Diagnosis: A Nematosphaeropsis with short and stout processes connected distally by stout trabeculae, which are triangular in cross section. Parasutural structures are missing on the central body.
Description (annotated): Chorate cysts with spherical to slightly ovoidal central bodies and sutural processes and trabeculae forming an outer sphere. Only one wall layer is visible in the light microscope. No structures are visible in the wall. The surface is smooth or punctate. Gonal and intergonal processes are present and no parasutural structures connect the bases of the processes. A few of the processes show a small proximate cavity, otherwise they are massive and buccinate. The processes are sort and stout, and annular in cross section. Distally they expand into connecting trabeculae, which make the paratabulation clearly visible. The trabeculae are triangular in cross section with one angle pointing against the capsule. The outer side of trabeculae is concave, especially above the processes, giving rise to a shape similar to the shape of the roman aquaducts. The lengths of the processes, are 9-12 µm, and uniform within a single specimen. The archaeopyle is formed by the loss of paraplate 3'' and the operculum is completely detached. The archaeopyle formula is P. The paratabulation formula, determined from the arrangement of the trabeculae, is (4', 6'', 6c, 5''', 1p, 1'''').
Paracingulum is helicoidal.
Affinities:
Piasecki, 1980, p. 70: Nematosphaeropsis aquaeducta
Nematosphaeropsis aquaeducta differs from other species of the genus Nematosphaeropsis by its short, simple and stout processes and trabeculae. Baltes (1969) figures a specimen identified as Nematosphaeropsis balcombiana Deflandre and Cookson, 1955. However, it appears from the figures that this specimen has the short and stout processes and trabeculae here used to define N. aquaeducta instead of the long and thin processes and trabeculae typical of N. balcombiana.
Wrenn, 1988, p.148-149
Specimens of Nematosphaeropsis lativittatus exhibiting widely spaced uncollapsed processes and trabeculae can express paratabulation clearly and can resemble Unipontidinium aquaeductum. However, the breadth of the processes, the extremely flared process terminations and the presence of paired penitabular trabeculae (that may or may not be more or less fused to each other) distinguish N. lativittatus from U. aquaeductum.
REMARK: This species was originally described as Nematosphaeropsis aquaeducta. Lentin and Williams, 1985, transferred it to Impagidinium, and Wrenn, 1988, on the basis of the species having single parasutural trabeculae rather than pairs of trabeculae, transferred it to the newly erected genus Unipontidinium.
Strauss (pers. comm., 1992) notes a facies dependant morphologic variability among the species in the Miocene from the Germanic Basin. Some of these varieties show small splits in the trabeculae, on the basis of which Strauss prefers to retain U. aquaeductum in Nematosphaeropsis.
Originally Nematosphaeropsis, subsequently Nematosphaeropsis?, thirdly Impagidinium, fourthly (and now) Unipontidinium.
Holotype: Piasecki, 1980, pl.1, figs.1-3
Originally Nematosphaeropsis, subsequently Nematosphaeropsis?, thirdly Impagidinium, fourthly (and now) Unipontidinium.
Age: mid Barremian (Middle Miocene?)
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Unipontidinium aquaeductum (Piasecki, 1980) Wrenn, 1988. According to Wrenn (1988, p.148), Unipontidinium aquaeductum has two wall layers, with the central body giving rise to processes (gonal, or gonal and intergonal) that are joined at their distal terminations by single parasutural trabeculae, processes may or may not be joined proximally by parasutural features on the central body. Paratabulation is 3-4', 6", 6c, 5-6"', 1p, 1"". The archeopyle is precingular resulting from the loss of plate 3". Size: length 38-47 µm, width 24-36 µm.
--------------------------------------------------
Original description: Piasecki, 1980, p.70: Nematosphaeropsis aquaducta
Diagnosis: A Nematosphaeropsis with short and stout processes connected distally by stout trabeculae, which are triangular in cross section. Parasutural structures are missing on the central body.
Description (annotated): Chorate cysts with spherical to slightly ovoidal central bodies and sutural processes and trabeculae forming an outer sphere. Only one wall layer is visible in the light microscope. No structures are visible in the wall. The surface is smooth or punctate. Gonal and intergonal processes are present and no parasutural structures connect the bases of the processes. A few of the processes show a small proximate cavity, otherwise they are massive and buccinate. The processes are sort and stout, and annular in cross section. Distally they expand into connecting trabeculae, which make the paratabulation clearly visible. The trabeculae are triangular in cross section with one angle pointing against the capsule. The outer side of trabeculae is concave, especially above the processes, giving rise to a shape similar to the shape of the roman aquaducts. The lengths of the processes, are 9-12 µm, and uniform within a single specimen. The archaeopyle is formed by the loss of paraplate 3'' and the operculum is completely detached. The archaeopyle formula is P. The paratabulation formula, determined from the arrangement of the trabeculae, is (4', 6'', 6c, 5''', 1p, 1'''').
Paracingulum is helicoidal.
Affinities:
Piasecki, 1980, p. 70: Nematosphaeropsis aquaeducta
Nematosphaeropsis aquaeducta differs from other species of the genus Nematosphaeropsis by its short, simple and stout processes and trabeculae. Baltes (1969) figures a specimen identified as Nematosphaeropsis balcombiana Deflandre and Cookson, 1955. However, it appears from the figures that this specimen has the short and stout processes and trabeculae here used to define N. aquaeducta instead of the long and thin processes and trabeculae typical of N. balcombiana.
Wrenn, 1988, p.148-149
Specimens of Nematosphaeropsis lativittatus exhibiting widely spaced uncollapsed processes and trabeculae can express paratabulation clearly and can resemble Unipontidinium aquaeductum. However, the breadth of the processes, the extremely flared process terminations and the presence of paired penitabular trabeculae (that may or may not be more or less fused to each other) distinguish N. lativittatus from U. aquaeductum.
REMARK: This species was originally described as Nematosphaeropsis aquaeducta. Lentin and Williams, 1985, transferred it to Impagidinium, and Wrenn, 1988, on the basis of the species having single parasutural trabeculae rather than pairs of trabeculae, transferred it to the newly erected genus Unipontidinium.
Strauss (pers. comm., 1992) notes a facies dependant morphologic variability among the species in the Miocene from the Germanic Basin. Some of these varieties show small splits in the trabeculae, on the basis of which Strauss prefers to retain U. aquaeductum in Nematosphaeropsis.