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Turbiosphaera sarrisii
From Fensome et al., 2019:
Turbiosphaera sarrisii (Archangelsky, 1969a, p.411, pl.2, figs.5–7) Fensome et al., 2019a, p.55.
Holotype: Archangelsky, 1969a, pl.2, figs.6–7; Fensome et al., 2019a, figs.20E–F.
Originally Polystephanephorus?, subsequently Senoniasphaera?, thirdly (and now) Turbiosphaera.
Questionable assignment: Fensome et al. (2019a. p.55).
Age: Eocene.
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Original description: [Archangelsky, 1969a] (translated from Spanish):
Polystephanephorus (?) sarrisii n. sp.
Pl. II, figs. 5, 6, 7
DIAGNOSIS. Subspherical to oval body, composed of an inner membrane (1.5 μ) thicker than the outer membrane; outer membrane giving rise to membranous processes, frequently tubuliform, generally perforated, which narrow towards the apex or are typically cylindrical. Number of processes: about 12; processes of variable width, but all of similar length; processes sometimes united by very delicate distal trabeculae, generally laminar. Apical archeopyle.
HOLOTYPE: microscope slide no. 709, coordinates 30.2/100.3.
MEASUREMENTS: body length: 43 μ; width of body: 40 μ; archeopyle: 23 μ; processes: 14 μ
DISTRIBUTION: Río Turbio Formation, D-15, level 687-689 m. Eocene.
OTHER MEASUREMENTS (specimens from the same provenance): body length: 43-61 μ (15 ex.); body width: 34-51 μ (15 ex.); archeopyle: 22-36 μ (10 ex.); length of processes: 10-17 μ.
DISCUSSION AND COMPARISONS. This curious species appears to be restricted exclusively to a single level, in well D-15; the frequency of the material allows its diagnosis with relative ease. More problematic, however, is the generic assignment. Indeed, the species most similar to ours is undoubtedly Cannosphaeropsis urnaformis Cookson (1953) and Deflandre and Cookson (1955), from the Tertiary of Australia. It was transferred to the genus Polystephanephorus by Sarjeant (1961), who typified it with a Jurassic species from Europe, P. calathus. According to the genus definition, the tubular processes are formed by the union of individual processes that meet distally by trabeculae that form a distal ring. In our case, these distal rings can occasionally be seen, but the individual processes cannot; instead, the tubes are formed by highly perforated membranes. Possibly, the degree of concrescence of the individual processes in this species reached a state similar to that sometimes observed in Turbiosphaera filosa. We also do not know the archeopyle in the European and Australian forms. Therefore, the reference of our taxon to Polystephanephorus is made with reservations.
Our specimens are in many respects similar to those described as Cannosphaeropsis urnaformis Cookson, a species originally assigned to the Lower to Middle Eocene and now uncertainly placed in the Oligocene of Australia. Our specimens have a similar body and appendage size, which may very occasionally be joined distally by very delicate trabeculae (as mentioned by Deflandre and Cookson, 1955, p. 284). The membranes of the appendages or processes are frequently perforated; in our species, we do not observe the widening of the processes toward the distal sector, which gives them an urn-like appearance in the Australian species. This difference is considered valid for the creation of a new species for the Patagonian individuals.
The presence of an archeopyle in our specimens, and its absence in the Australian ones, may be due to rather fortuitous causes (as is the case with Aiora fenestrata, for example). The archeopyle, from what has been observed, appears to be apical (see Plate 2, Figs. 5 and 7).
This species is dedicated to Dr. Miguel Sarris, geologist at Yacimientos Carboníferos Fiscales.
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Comments Fensome et al., 2019a:
Archangelsky (1969) considered that this species has an apical archaeopyle. However, G. R. Guerstein (personal communication 2017) noted that a restudy of the type material confirmed that this species has a precingular archaeopyle. Following suggestions by Archangelsky (1969), Gonzalez Estebenet et al. (2015, 2016) considered Senoniasphaera sarrisii to be an extreme member of the Turbiosphaera filosa complex (their morphotype 1). These authors considered the morphological variation within the Turbiosphaera filosa complex to parallel the variation described by Benedek & Gocht (1981 and references therein) and Pross (2001) for Thalassiphora pelagica. However, Gonzalez Estebenet et al. (2015, 2016) made no formal taxonomic proposals, so for now we questionably transfer Senoniasphaera? sarrisii to Turbiosphaera.
Stratigraphical occurrence. The type material is from the Eocene of Argentina.
Turbiosphaera sarrisii (Archangelsky, 1969a, p.411, pl.2, figs.5–7) Fensome et al., 2019a, p.55.
Holotype: Archangelsky, 1969a, pl.2, figs.6–7; Fensome et al., 2019a, figs.20E–F.
Originally Polystephanephorus?, subsequently Senoniasphaera?, thirdly (and now) Turbiosphaera.
Questionable assignment: Fensome et al. (2019a. p.55).
Age: Eocene.
---------------------------------------------------------------------------------------------------
Original description: [Archangelsky, 1969a] (translated from Spanish):
Polystephanephorus (?) sarrisii n. sp.
Pl. II, figs. 5, 6, 7
DIAGNOSIS. Subspherical to oval body, composed of an inner membrane (1.5 μ) thicker than the outer membrane; outer membrane giving rise to membranous processes, frequently tubuliform, generally perforated, which narrow towards the apex or are typically cylindrical. Number of processes: about 12; processes of variable width, but all of similar length; processes sometimes united by very delicate distal trabeculae, generally laminar. Apical archeopyle.
HOLOTYPE: microscope slide no. 709, coordinates 30.2/100.3.
MEASUREMENTS: body length: 43 μ; width of body: 40 μ; archeopyle: 23 μ; processes: 14 μ
DISTRIBUTION: Río Turbio Formation, D-15, level 687-689 m. Eocene.
OTHER MEASUREMENTS (specimens from the same provenance): body length: 43-61 μ (15 ex.); body width: 34-51 μ (15 ex.); archeopyle: 22-36 μ (10 ex.); length of processes: 10-17 μ.
DISCUSSION AND COMPARISONS. This curious species appears to be restricted exclusively to a single level, in well D-15; the frequency of the material allows its diagnosis with relative ease. More problematic, however, is the generic assignment. Indeed, the species most similar to ours is undoubtedly Cannosphaeropsis urnaformis Cookson (1953) and Deflandre and Cookson (1955), from the Tertiary of Australia. It was transferred to the genus Polystephanephorus by Sarjeant (1961), who typified it with a Jurassic species from Europe, P. calathus. According to the genus definition, the tubular processes are formed by the union of individual processes that meet distally by trabeculae that form a distal ring. In our case, these distal rings can occasionally be seen, but the individual processes cannot; instead, the tubes are formed by highly perforated membranes. Possibly, the degree of concrescence of the individual processes in this species reached a state similar to that sometimes observed in Turbiosphaera filosa. We also do not know the archeopyle in the European and Australian forms. Therefore, the reference of our taxon to Polystephanephorus is made with reservations.
Our specimens are in many respects similar to those described as Cannosphaeropsis urnaformis Cookson, a species originally assigned to the Lower to Middle Eocene and now uncertainly placed in the Oligocene of Australia. Our specimens have a similar body and appendage size, which may very occasionally be joined distally by very delicate trabeculae (as mentioned by Deflandre and Cookson, 1955, p. 284). The membranes of the appendages or processes are frequently perforated; in our species, we do not observe the widening of the processes toward the distal sector, which gives them an urn-like appearance in the Australian species. This difference is considered valid for the creation of a new species for the Patagonian individuals.
The presence of an archeopyle in our specimens, and its absence in the Australian ones, may be due to rather fortuitous causes (as is the case with Aiora fenestrata, for example). The archeopyle, from what has been observed, appears to be apical (see Plate 2, Figs. 5 and 7).
This species is dedicated to Dr. Miguel Sarris, geologist at Yacimientos Carboníferos Fiscales.
---------------------------------------------------------------------------------------------------
Comments Fensome et al., 2019a:
Archangelsky (1969) considered that this species has an apical archaeopyle. However, G. R. Guerstein (personal communication 2017) noted that a restudy of the type material confirmed that this species has a precingular archaeopyle. Following suggestions by Archangelsky (1969), Gonzalez Estebenet et al. (2015, 2016) considered Senoniasphaera sarrisii to be an extreme member of the Turbiosphaera filosa complex (their morphotype 1). These authors considered the morphological variation within the Turbiosphaera filosa complex to parallel the variation described by Benedek & Gocht (1981 and references therein) and Pross (2001) for Thalassiphora pelagica. However, Gonzalez Estebenet et al. (2015, 2016) made no formal taxonomic proposals, so for now we questionably transfer Senoniasphaera? sarrisii to Turbiosphaera.
Stratigraphical occurrence. The type material is from the Eocene of Argentina.