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Sangiorgia marretiae
Original description: [Sluijs and Brinkhuis, 2024, p. 456-457]:
Sangiorgia marretiae sp. nov.
Plates 8, S28, S29
Etymology. Named for Fabienne Marret-Davies in recognition of her achievements in marine palynology, at Liverpool University, United Kingdom.
Diagnosis. Cysts proximochorate; small to intermediate in size, body subspherical, bearing gonal and intergonal, solid processes, of which many, but not all, distally interconnect. The connections are formed by single, ribbon-like trabecular features, which sometimes split into two strands, like the “tramlines” typical for Nematosphaeropsis. The gonal locations are typically distally marked by somewhat broad, trifurcate projections, typical for Spiniferites species. However, since these tri- and occasionally bifurcations occur distally on top of the connecting trabeculae, the overall habitus is also reminiscent of species of Cannosphaeropsis, notably C. utinensis (e.g., “barbed wire style” distal trabeculae). Proximal markings between process bases are limited to faint parasutural lines; paratabulation standard sexiform gonyaulacacean,
like all members of the spiniferitioids; archeopyle precingular, Type P, operculum free.
Holotype. Plate 8, E–H
Paratypes. Plate 8, A–D, I–L
Material. IODP 302 Hole M0004A, Lomonosov Ridge, Arctic Ocean
Type locality and horizon. IODP 302 Hole M0004A, Lomonosov Ridge, Arctic Ocean, lower Eocene, Core 302-0004A-27X-3-80/82
Age. Early Eocene
Description.
Shape: body subspherical.
Wall relationships: autophragm only, or endophragm and periphragm “appressed” between processes.
Wall features: autophragm smooth or faintly ornamented. Parasutural features between process bases faint (e.g., traces of low ridges) or absent altogether; features may be present over entire cyst or locally.
Processes: gonal only, or gonal and intergonal; tips of connected and unconnected processes are distally trifurcate (gonal) or bifurcate (intergonal) and occur on top of the distally connecting trabeculae. A variable portion of the processes distally links to form trabeculae that connect several processes, sometimes leading to a partial and incomplete parasutural network. Connections between processes may comprise one (as in Cannosphaeropsis) or two (as in Nematosphaeropsis) trabeculae.
Paratabulation: positions of gonal processes and faint
sutural ornamentation indicates standard sexiform
gonyaulacacean (Spiniferitioid) tabulation.
Archeopyle: precingular, Type P (3” only); operculum free.
Paracingulum: indicated, if at all, by parasutural lines and position of gonal processes.
Parasulcus: indicated, if at all, by parasutural lines.
Dimensions. Diameter central body 22(28)35 µm (n = 10).
Holotype. 28 µm.
Paratypes. 35 µm, 22 µm.
Stratigraphic range/occurrence. Early Eocene
Remarks. It differs from S. pospelovae in being thinwalled, more fragile, transparent, and smaller and by the presence of distal, tri- or bifurcated processes occurring on top of the distally connecting trabeculae. In overall habitus and variations, this species superficially comes across as a Spiniferites but differs by forming a distinct, but incomplete, distally connecting network of essentially simple (sets of) strands or trabeculae.
Sangiorgia marretiae sp. nov.
Plates 8, S28, S29
Etymology. Named for Fabienne Marret-Davies in recognition of her achievements in marine palynology, at Liverpool University, United Kingdom.
Diagnosis. Cysts proximochorate; small to intermediate in size, body subspherical, bearing gonal and intergonal, solid processes, of which many, but not all, distally interconnect. The connections are formed by single, ribbon-like trabecular features, which sometimes split into two strands, like the “tramlines” typical for Nematosphaeropsis. The gonal locations are typically distally marked by somewhat broad, trifurcate projections, typical for Spiniferites species. However, since these tri- and occasionally bifurcations occur distally on top of the connecting trabeculae, the overall habitus is also reminiscent of species of Cannosphaeropsis, notably C. utinensis (e.g., “barbed wire style” distal trabeculae). Proximal markings between process bases are limited to faint parasutural lines; paratabulation standard sexiform gonyaulacacean,
like all members of the spiniferitioids; archeopyle precingular, Type P, operculum free.
Holotype. Plate 8, E–H
Paratypes. Plate 8, A–D, I–L
Material. IODP 302 Hole M0004A, Lomonosov Ridge, Arctic Ocean
Type locality and horizon. IODP 302 Hole M0004A, Lomonosov Ridge, Arctic Ocean, lower Eocene, Core 302-0004A-27X-3-80/82
Age. Early Eocene
Description.
Shape: body subspherical.
Wall relationships: autophragm only, or endophragm and periphragm “appressed” between processes.
Wall features: autophragm smooth or faintly ornamented. Parasutural features between process bases faint (e.g., traces of low ridges) or absent altogether; features may be present over entire cyst or locally.
Processes: gonal only, or gonal and intergonal; tips of connected and unconnected processes are distally trifurcate (gonal) or bifurcate (intergonal) and occur on top of the distally connecting trabeculae. A variable portion of the processes distally links to form trabeculae that connect several processes, sometimes leading to a partial and incomplete parasutural network. Connections between processes may comprise one (as in Cannosphaeropsis) or two (as in Nematosphaeropsis) trabeculae.
Paratabulation: positions of gonal processes and faint
sutural ornamentation indicates standard sexiform
gonyaulacacean (Spiniferitioid) tabulation.
Archeopyle: precingular, Type P (3” only); operculum free.
Paracingulum: indicated, if at all, by parasutural lines and position of gonal processes.
Parasulcus: indicated, if at all, by parasutural lines.
Dimensions. Diameter central body 22(28)35 µm (n = 10).
Holotype. 28 µm.
Paratypes. 35 µm, 22 µm.
Stratigraphic range/occurrence. Early Eocene
Remarks. It differs from S. pospelovae in being thinwalled, more fragile, transparent, and smaller and by the presence of distal, tri- or bifurcated processes occurring on top of the distally connecting trabeculae. In overall habitus and variations, this species superficially comes across as a Spiniferites but differs by forming a distinct, but incomplete, distally connecting network of essentially simple (sets of) strands or trabeculae.