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Seriliodinium
From Williams et al., 2017:
[Seriliodinium, Eaton, 1996, p. 152-153
Type species: Seriliodinium explicatum, Eaton, 1996 (pl.1, figs.1–2; text-figs.2A–B,5A–B)]
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Original description: [Eaton, 1996]:
Diagnosis:
Trabeculate chorate cysts with a subcircular to oval outline in dorso-ventral view, and a cyst body which is rounded cruciform to oval in outline. Processes are characteristically confined to the peripheral region of the cyst body, leaving the mid-ventral and mid-dorsal areas essentially process-free, and resulting in a marginate overall appearance. The majority of the processes are gonal in position and distally trifurcate. More complex processes, including those which characterise the paracingular zone, each occupy several gonal sites and are distally multifurcate. Parasutural septa are variably developed, and occur as low ridges or membranes of variable height, which link adjacent processes. The processes are united distally by a network of single, parasutural, rope-like trabeculae, which is developed peripherally, and generally leaves the mid-ventral and mid-dorsal areas open. The distribution of the processes, parasutural septa and trabeculae defines a gonyaulacoid paratabulation the archaeopyle is simple, precingular, formed by the loss of paraplate 3".
Discussion:
Seriliodinium is characterised by a gonyaulacoid paratabulation, a simple precingular archaeopyle, a broadly spiniferitid style of process form and distribution, and a distal network of trabeculae. These features imply some degree of similarity to Unipontidinium Wrenn, 1988, Nematosphaeropsis Deflandre and Cookson emend. Wrenn, 1988, and Cannosphaeropsis 0. Wetzel emend. Marheinecke, 1992. Seriliodinium is closest to Unipontidinium in possessing single parasutural trabeculae, but differs in having a restricted process distribution and a limited development of trabeculae which results in an overall marginate appearance. These distributional features also serve to distinguish Seriliodinium from Nematosphaeropsis which is further characterised by paired, penitabular trabeculae rather than single parasutural elements. In Cannosphaeropsis, processes are restricted to the apical and antapical poles, and the network of single trabeculae supports small trifurcate and bifurcate processes. This contrasts with the wider distribution of processes in Seriliodinium, and the fact that its trabeculae define the outer limits of the cyst.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Seriliodinium Eaton, 1996. Diagnosis according to Eaton (1996, p.152-153), is a trabeculate chorate cyst with a subcircular to oval outline in dorso-ventral view, and a cyst body which is rounded cruciform to oval in outline. Processes are characteristically confined to the peripheral region of the cyst body, leaving the mid-ventral and mid-dorsal areas essentially process-free, and resulting in a marginate overall appearance. The majority of the processes are gonal in position and distally trifurcte. More complex processes, including those which characterise the paracingular zone, each occupy several gonal sites and are distally multifurcate. Parasutural septa are variably developed and occur as low ridges or membranes or variable height, which link adjacent processes. The processes are united distally by a network of single, parasutural, rope-like trabeculae, which is developed peripherally, and generally leaves the mid-ventral and mid-dorsal areas open. The distribution of the processes, parasutural septa and trabeculae defines a gonyaulacoid paratabulation; the archeopyle is simple, precingular, formed by the loss of 3". Unlike Nematosphaeropsis, the trabeculae are not paired.
[Seriliodinium, Eaton, 1996, p. 152-153
Type species: Seriliodinium explicatum, Eaton, 1996 (pl.1, figs.1–2; text-figs.2A–B,5A–B)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eaton, 1996]:
Diagnosis:
Trabeculate chorate cysts with a subcircular to oval outline in dorso-ventral view, and a cyst body which is rounded cruciform to oval in outline. Processes are characteristically confined to the peripheral region of the cyst body, leaving the mid-ventral and mid-dorsal areas essentially process-free, and resulting in a marginate overall appearance. The majority of the processes are gonal in position and distally trifurcate. More complex processes, including those which characterise the paracingular zone, each occupy several gonal sites and are distally multifurcate. Parasutural septa are variably developed, and occur as low ridges or membranes of variable height, which link adjacent processes. The processes are united distally by a network of single, parasutural, rope-like trabeculae, which is developed peripherally, and generally leaves the mid-ventral and mid-dorsal areas open. The distribution of the processes, parasutural septa and trabeculae defines a gonyaulacoid paratabulation the archaeopyle is simple, precingular, formed by the loss of paraplate 3".
Discussion:
Seriliodinium is characterised by a gonyaulacoid paratabulation, a simple precingular archaeopyle, a broadly spiniferitid style of process form and distribution, and a distal network of trabeculae. These features imply some degree of similarity to Unipontidinium Wrenn, 1988, Nematosphaeropsis Deflandre and Cookson emend. Wrenn, 1988, and Cannosphaeropsis 0. Wetzel emend. Marheinecke, 1992. Seriliodinium is closest to Unipontidinium in possessing single parasutural trabeculae, but differs in having a restricted process distribution and a limited development of trabeculae which results in an overall marginate appearance. These distributional features also serve to distinguish Seriliodinium from Nematosphaeropsis which is further characterised by paired, penitabular trabeculae rather than single parasutural elements. In Cannosphaeropsis, processes are restricted to the apical and antapical poles, and the network of single trabeculae supports small trifurcate and bifurcate processes. This contrasts with the wider distribution of processes in Seriliodinium, and the fact that its trabeculae define the outer limits of the cyst.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Seriliodinium Eaton, 1996. Diagnosis according to Eaton (1996, p.152-153), is a trabeculate chorate cyst with a subcircular to oval outline in dorso-ventral view, and a cyst body which is rounded cruciform to oval in outline. Processes are characteristically confined to the peripheral region of the cyst body, leaving the mid-ventral and mid-dorsal areas essentially process-free, and resulting in a marginate overall appearance. The majority of the processes are gonal in position and distally trifurcte. More complex processes, including those which characterise the paracingular zone, each occupy several gonal sites and are distally multifurcate. Parasutural septa are variably developed and occur as low ridges or membranes or variable height, which link adjacent processes. The processes are united distally by a network of single, parasutural, rope-like trabeculae, which is developed peripherally, and generally leaves the mid-ventral and mid-dorsal areas open. The distribution of the processes, parasutural septa and trabeculae defines a gonyaulacoid paratabulation; the archeopyle is simple, precingular, formed by the loss of 3". Unlike Nematosphaeropsis, the trabeculae are not paired.