Nannotax3 - ntax_cenozoic - Lithoptychius pileatus

Citation: Lithoptychius pileatus (Bukry, 1973) Aubry in Aubry et al. 2011

Basionym: Fasciculithus pileatus Bukry, 1973

Taxonomic discussion: Distinguishing this taxon from L. janii is quite straightforward, but it is clearly similar and may prove to be conspecific.
One of the specimens included by Bukry (1973) in his original description (his plate 2 fig 1) is better placed in F. janii, and hence the two species have been confused in the literature - see Steurbaut & Sztrakos (2008), Monechi et al. (2012).

Distinguishing features: Cylindrical column that broadens distally and a wide, disc-like apical cycle that is crystallographically distinct.

Geological Range:
Last occurrence (top): in mid part of NP6 zone (50% up, 59.3Ma, in Thanetian stage). Data source: Varol, 1989, fig. 12.4
First occurrence (base): near top of NP4 zone (90% up, 61.7Ma, in Danian stage). Data source: Varol, 1989, fig. 12.4; Monechi et al. 2013, fig 6

References:

Aubry, M. P., Bord, D. & Rodriguez, O. (2011). New taxa of the Order Discoasterales Hay 1977. Micropaleontology. 57(3): 269-287. gs

Bown, P. R. (2016). Paleocene calcareous nannofossils from Tanzania (TDP sites 19, 27 and 38). Journal of Nannoplankton Research. 36(1): 1-32. gs V O

Bukry, D. (1973g). Phytoplankton stratigraphy, Deep Sea Drilling Project Leg 20, Western Pacific Ocean. Initial Reports of the Deep Sea Drilling Project. 20: 307-317. gs V O

Monechi, S., Reale, V., Bernaola, G. & Balestra, B. (2012). Taxonomic review of early Paleocene fasciculiths. Micropaleontology. 58(4): 351-365. gs

Monechi, S., Reale, V., Bernaola, G. & Balestra, B. (2013). The Danian/Selandian boundary at Site 1262 (South Atlantic) and in the Tethyan region: Biomagnetostratigraphy, evolutionary trends in fasciculiths and environmental effects of the Latest Danian Event. Marine Micropaleontology. 98(1): 28-40. gs

Okada, H. & Thierstein, H. R. (1979). Calcareous nannoplankton - Leg 43, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 43: 507-573. gs V O

Perch-Nielsen, K. (1985a). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs

Steurbaut, E. & Sztrákos, K. (2008). Danian/Selandian boundary criteria and North Sea Basin–Tethys correlations based on calcareous nannofossil and foraminiferal trends in SW France. Marine Micropaleontology. 67: 1-29. gs

Varol, O. (1989c). Palaeocene calcareous nannofossil biostratigraphy. In, Crux, J. A. & van Heck, S. E. (eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series. 265-310. gs V O

Comments (1)

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Vladimir Musatov (Saratov, Russia)

Hi Jeremy

Lithoptychius pileatus

Last occurrence (top): in mid part of NP6 zone.

In the zonal division scheme indicated by its disappearance in the middle zone NP5. (http://mikrotax.org/Nannotax3/graphics/nanno-zonations1.svg.

The truth is out there))

14th May 2017 7:50pm

Jeremy Young

Hi Vladimir

Interesting observation. The mid NP6 LAD quoted here is bsed on Varol (1998) who used the LAD of F. pileatus within his zonal scheme. However, the taxon is certiainly more common in top NP4-lower NP5. A possible explanation is provided by Agnini et al. 2007 (fig. 5) who show an LCO in mid NP5 but a trail of rare occurrences up into NP6 . I am not sure where the mid NP5 LAD in time scale creator comes from. What is your experience?

Jeremy

15th May 2017 9:44pm

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Tags	LITHS: nannolith-radiate, circular, cylindrical, CROSS-POLARS: V-prominent, R-prominent,
Metrics	Lith size: 4->8µm; Data source notes: size (width) from illustrated specimens (OD size range of 5-12 µm not obviously supported)

Lithoptychius pileatus

References:

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