J. Nannoplankton Res. 29 (1), 2007, pp.1-4 © 2007 International Nannoplankton Association
ISSN 1210-8049 Printed by Cambridge University Press, UK1

New calcareous nannofossil species from the Cretaceous
Budden Canyon Formation, Great Valley Sequence,
northern California (USA)
Allan Gil S. Fernando*, Hisatake Okada
Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, N10 W8 Sapporo, 060-0810 Japan. *Present address:
National Institute of Geological Sciences, University of the Philippines, Diliman, Quezon City 1101, Philippines; braarudosphaera@yahoo.com
Manuscript received 24th August, 2006; revised manuscript accepted 19th January, 2007

Abstract Two new species of calcareous nannofossil, Diloma californica and Prediscosphaera quasispinosa,
are described from the Budden Canyon Formation of the Great Valley Sequence in northern California (USA). D.
californica was observed from sediments of Aptian age and has also been observed in rocks of similar age in theVocontian Basin (SE France), suggesting its potential for wide geographic correlation. P. quasispinosa, on the otherhand, appears to be restricted to the Cenomanian, and is presently known only from sediments of northern California.
Keywords Diloma californica, Prediscosphaera quasispinosa, calcareous nannofossils, Cretaceous, Budden
Canyon Formation, Great Valley Sequence, California

1. Introduction
Calcareous nannofossil biostratigraphic investigation ofsediments from the Budden Canyon Formation of northern California (Fernando, 2006; Fernando et al., subm.)
has revealed several new taxa, two of which are describedin this paper: Diloma californica and Prediscosphaera
quasispinosa. Although both species are rare, the occurrence of D. californica in rocks of similar age in theVocontian Basin (SE France: Fernando, 2006) suggeststhat this species may be useful for correlation on a broad
geographical scale. The samples from California werecollected from outcrops along the North Fork
Cottonwood Creek in Shasta County (Figure 1; seeFernando et al., subm., for further details). The samples
from the Vocontian Basin were collected from the Goguel
Level (‘Niveau Goguel’) of Core 2003-GOG1, drilled inLes Sauzeries (~10km north of Barrême), in connection
with the Cretaceous Oceanic Anoxic Events Project of the21st Century Center of Excellence (COE) Program ofHokkaido University.

BA
Figure 1: A) Map of California and location of study area in the Great
Valley Sequence. B) Location of North Fork Cottonwood Creek section(solid box), Shasta County, northern California (USA), modified after
Murphy & Rodda (1996)

2. Taxonomy
Sediment samples and original digital images of the newtaxa are stored at the History of Earth’s Environment
Research Group Laboratory of Hokkaido University(Sapporo, Japan). Original smear-slides, on the otherhand, are stored at the Nannoworks Laboratory of theNational Institute of Geological Sciences, University ofthe Philippines (Quezon City, Philippines).
Family EIFFELLITHACEAE Reinhardt, 1965
Genus Diloma Wind & Cepek, 1979
Type species Diloma primitiva (Worsley, 1971) Wind &Cepek, 1979
Diloma californica sp. nov.
Pl.1, figs 1-16. Derivation of name: Named after thestate of California (USA), where the species was firstobserved. Diagnosis: Medium-sized, (narrowly) ellipticalcoccolith, surrounded by a relatively narrow (<1µm) rim.
A plate (?) occupies the central area and has a prominent
median suture, parallel to the long axis of the coccolith.
The element construction of the rim and the central plate
are not visible under the light-microscope, although, inseveral specimens, the rim appears to be constructed of(short) overlapping elements (Pl.1, fig.16). Moderatelypreserved specimens (SE France samples) display rims
with a beaded appearance (Pl.1, figs 10-15). Undercrossed-polars (XPL), with the main axes of the coccolithparallel to the polarising direction of the microscope, both
the rim and the central area exhibit low to moderate birefringence, and the longitudinal suture is visible (Pl.1, figs
1, 10). At ~45˚, the central area appears brighter than therim and the suture may or may not be visible (Pl.1, figs 7,8, 12). At certain angles, the central area appears to bedivided into four quadrants, the boundaries of which correspond to the axes of the ellipse, and with each diagonally opposite quadrant exhibiting similar properties in XPL

2Fernando, Okada(Pl.1, figs 5, 6, 11, 14, 15). Remarks: Wind & Cepek(1979, pp.248-249, pl.8, figs 8-17) illustrated a specimen(Diloma sp.) similar to D. californica. Similarities include
the bright central area under XPL and the four quadrants
comprising the central area. However, several of their
specimens of Diloma sp. are divided into six sections, twoof which are small triangular segments, situated along theshort axis (Wind & Cepek, 1979, pl.8, figs 12-15). This
habit was not observed in specimens of D. californica
from either California or the Vocontian Basin.
Additionally, the size of D. californica is smaller thanDiloma sp. (7.5-9.0µm) and Diloma sp. has a geologicalrange within the Hauterivian, in contrast to D. californica,
which is presently restricted to the Early Aptian. Wind &Cepek (1979) suggested the possibility that specimens ofDiloma sp. could represent overgrown specimens of D.
placinum, which also occurs within the Hauterivian. Most
specimens of D. californica exhibit moderate preservation, where both etching and overgrowth (as suggested by
the beaded appearance of the rim in some D. californica
specimens) are possible. However, as the diagnostic features for the well- and moderately-preserved specimens
are similar, it is unlikely that D. californica could represent overgrown specimens of Diloma sp. Dimensions:
Length = 5-6µm; width = 3-4µm. Holotype: Pl.1, figs 19, Sample US-040 (northern California). Paratypes: Pl.1,figs 10-13, Sample GO-013, Section 17-4, Core 2003GOG1, Les Sauzeries, Vocontian Basin, SE France; Pl.1,figs 14-16, Sample GO-015, Section 17-4, Core 2003GOG1, Les Sauzeries, Vocontian Basin, SE France. Type
locality: Ono, North Fork Cottonwood Creek section,Ono Quadrangle, Shasta County, northern California(Great Valley Sequence), USA. Sec.12 of T.30N., R.7W.
(Murphy et al., 1969). Type Level: Lower Aptian, Sample
US-040, base of upper Chickabally Member, Budden
Canyon Formation (nannofossil zone BC19 of Bown etal., 1998). Occurrence: BC19-BC20 in California(Fernando, 2006; Fernando et al., subm.); CC7a (ofSissingh, 1977, as modified by Perch-Nielsen, 1985) andNC6A-NC7A (of Roth, 1978, as modified by Bralower etal., 1995) in the Le Sauzeries section, Vocontian Basin,SE France (Fernando, 2006).
Family PREDISCOSPHAERACEAE Rood et al.,1971
Genus Prediscosphaera Vekshina, 1959
Type species P. cretacea (Arkhangelsky, 1912) Gartner,
1968
Prediscosphaera quasispinosa sp. nov.
Pl.1, fig.17. Derivation of name: From the Latin quasi,
meaning ‘having similarities to’, referring to its resemblance in appearance to P. spinosa. Diagnosis: A small,(normally) elliptical species of Prediscosphaera, which
has a thick inner-cycle and a thick, subaxial central cross,occupying most of the central area. Remarks: P. quasispinosa most closely resembles P. spinosa with regards tobasic morphology. They are similar in that the cross-barsof P. spinosa could either be axial or not perfectly alignedwith the major and minor axes of the ellipse (Gartner,1968; Bukry, 1969). However, the general outline of thetwo taxa is different (i.e. P. spinosa is rectangular in outline), and the cross-bars and inner cycle of P. spinosa arenarrower than those of P. quasispinosa (see Pl.1, fig.18
for comparison). P. cretacea, another elliptical form, hascross-bars that are not aligned with the major and minoraxes of the ellipse (Pl.1, fig.19). The recorded distributionof P. quasispinosa is, at present, restricted to northernCalifornia, although J. Self-Trail (pers. comm., 2007) has
also observed P. quasispinosa from sediments of
Cenomanian age of the Atlantic Coastal Plain.
Dimensions: Length = 5µm; width = 4µm. Holotype:
Pl.1, fig.17, Sample US-062 (northern California). Type
locality: North Fork Cottonwood Creek section, Ono
Quadrangle, Shasta County, northern California (GreatValley Sequence), USA. Sec.21 of T.30N., R.6W.
(Murphy et al., 1969). Type level: Upper Cenomanian,Sample US-062, Gas Point Member, Budden Canyon
Formation (nannofossil subzone UC3e of Burnett, 1998).
Occurrence: UC3e-UC5c in California (Fernando, 2006;Fernando et al., subm.).
Acknowledgements
The authors would like to thank Drs Jackie Lees and Jean SelfTrail for reviewing the initial draft and for their helpful comments and suggestions. AGSF would also like to thank Dr. Leesfor the encouragement to write this taxonomic paper. This paper
would not have been possible without the following people whocollected the samples in California and SE France: Drs
Kazushige Tanabe, Michael Murphy, Hiroshi Nishi, Kazuto
Kodama, Reishi Takashima, Ken Sawada, Kazuyoshi Moriya,
Yasuhiro Iba and Koichi Iijima. This paper is supported by the21st Century COE Program ‘The Neoscience of Natural
History’ of the Hokkaido University.

References
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Nannofossil Biostratigraphy. British MicropalaeontologicalSociety Series. Chapman & Hall/Kluwer Academic Press,London: 86-131.
Bralower, T.J., Leckie, R.M., Sliter, W.V. & Thierstein, H.R.
1995. An Integrated Cretaceous Microfossil Biostratigraphy.
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Bukry, D. 1969. Upper Cretaceous coccoliths from Texas andEurope. The University of Kansas PaleontologicalContributions, Article 51 (Protista 2): 1-79.
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Micropalaeontological Society Series. Chapman &Hall/Kluwer Academic Press: 132-199.
Fernando,A.G.S.
2006.
CalcareousNannofossil
Biostratigraphy and Assemblages of the Mid-CretaceousNew calcareous nannofossil species...California(Barremian-Turonian) Budden Canyon Formation (northernCalifornia, USA) and Oceanic Anoxic Event (OAE) 1a in SE
France and OAE2 in the Tethyan and Pacific Regions.
Unpublished PhD thesis, Hokkaido University, Sapporo,
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Fernando, A.G.S., Nishi, H., Tanabe, K., Moriya, K., Iba, Y.,
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3

Fernando, Okada

4Plate 1
XPL = cross-polarised light; PC = phase-contrast; BF = bright-fieldholotype, XPL

holotype, PC

holotype, PC

holotype, XPL

1µm

Diloma californica Sample US-040, upper Chickabally Member, Budden Canyon Formation, Great Valley Sequence (GVS), California
holotype, XPLholotype, XPLholotype, XPLholotype, XPLholotype, PCparatype, XPLparatype, XPLparatype, XPL

D. californica Sample GO-013, Section 17-4, Core 2003-GOG1, Les Sauzeries, Vocontian Basin, SE Franceparatype, BF

PC

XPL

XPL

D. californica Sample GO-015, Section 17-4, Core 2003-GOG1, Les Sauzeries, Vocontian Basin, SE Franceholotype, XPL

Prediscosphaera quasispinosa
Sample US-062, Gas Point
Member, Budden Canyon
Formation, GVS, California

XPL

P. spinosa Sample US-049,GVS, California

XPLP. cretacea Sample US-311,GVS, California