APPENDIX A

Paleontological Systematic Description

FSU and UP abbreviations for the holotypes of the new species refer to film and frame numbers that are stored, respectively, at the Department of Geology of the Florida State University (U.S.A.) and at the Istituto di Geologia at the Università degli Studi di Parma (Italy). Holotype measurements are indicated in parentheses.

Genus AMAUROLITHUS Gartner and Bukry, 1975

Amaurolithus delicatus Gartner and Bukry, 1975
(Pl. 13, Figs. 25, 26)

Amaurolithus primus (Bukry and Percival, 1971) Gartner and Bukry, 1975
(Pl. 13, Figs. 23, 24)

Genus BICOLUMNUS Wei and Wise, 1990

Bicolumnus ovatus Wei and Wise, 1990
(Pl. 7, Figs. 15, 16)

Genus BLACKITES Hay and Towe, 1962

Blackites tenuis (Bramlette and Sullivan, 1961) Bybell, 1975
(Pl. 10, Figs. 7-9)

Genus BRAARUDOSPHAERA Deflandre, 1947

Braarudosphaera bigelowii (Gran and Braarud, 1935) Deflandre, 1947
(Pl. 14, Fig. 12)

Genus BRAMLETTEIUS Gartner, 1969

Bramletteius serraculoides Gartner, 1969
(Pl. 14, Figs. 17-20)

Genus CALCIDISCUS Kamptner, 1950

Remarks. Variations in size, shape, and central area features are used to differentiate the Calcidiscus species. Circular to elliptical placoliths have been observed. Most of the specimens have a sub-elliptical outline which make shape a difficult criteria for differentiating the diverse species. This is particularly evident in the late Oligocene to early Miocene, where most of the forms are smaller than 6 (am. The various species used for this study have been differentiated in the light microscope by overall size, the presence of a distinct central pore, and by the variable degree of imbrication of the elements of the shields (straight or kinked sutures).

Calcidiscus carlae (Lehotayova and Priewalder, 1978) Janin, 1992
(Pl. 1, Figs. 19, 20)

Calcidiscus fuscus (Backman, 1980) Janin, 1987
(Pl. 1, Figs. 7-10)

Calcidiscus leptoporus (Murray and Blackman, 1898) Loeblich and Tappan, 1978
(Pl. 1, Figs. 1-6)

Calcidiscus macintyrei (Bukry and Bramlette, 1966) Loeblich and Tappan, 1978
(Pl. 1, Figs. 29, 30)

Remarks. The FO of large (>11 µm), circular Calcidiscus with a closed central area occurs in the middle Miocene Zone NN7. Similar sized forms with a large central opening are grouped into Calcidiscus tropicus (Pl. 1, Figs. 21-28), which occurs earlier in the middle Miocene Zone NN6.

Calcidiscus pataecus (Gartner, 1967) n. comb.
(Pl. 1, Figs. 11, 12)

Coccolithus pataecus Gartner, 1967, p. 4, pl. 5, figs. 6, 7a, b, 8a, 8b.

Remarks. Calcidiscus pataecus include small, subelliptical Calcidiscus specimens (<6 µm) with a closed center and few elements. Calcidiscus leptoporus is a larger form with more elements, strongly imbricated and non-radial sutures.

Calcidiscus radiatus (Kamptner, 1954) Martin Perez and Aguodo, 1990
(Pl. 1, Figs.  13, 14)

Genus CAMURALITHUS n. gen.

Type species. Camuralithus pelliculathus, n. gen., n. sp.

Diagnosis. An elliptical placolith composed of three shields. The proximal and intermediate shields are strongly curved, closely adpressed and are equal in diameter. The third shield, in the distal position, is smaller and has steeply inclined elements. The central area is large and may be spanned by diverse structure.

Derivation of name. From Latin camur, bent, and Greek, lithos, rock.

Camuralithus pelliculathus n. sp.
(Pl. 2, Figs. 1-12)

Diagnosis. A species of Camuralithus composed of three shields and a central area spanned by an X-shaped cross. A central plate may be present on the proximal side that supports the central cross.

Description. A small to medium elliptical form with 40 to 45 elements in the two lower shields. In cross-polarized light, the rim exhibits a unicyclic, white extinction pattern and the central cross is faintly birefringent. In phase contrast light, the central cross appears dark.

Size. 4 to 6 µm (holotype: 4.0 µm).

Differentiation. Camuralithus pelliculathus is differentiated from species of the genus Chiasmolithus by its three superimposed shield structure and by the absence of a large, bicyclic distal shield with a well developed outer cycle.

Derivation of name. From Latin pellicula, skin.

Holotype. FSU-F138 (Pl. 2, Fig. 1); FSU-F145 (Pl. 2, Fig. 2); FSU-F147 (Pl. 2, Fig. 3); FSU-FO53-D19 (Pl. 2, Fig. 4); FSU-FO53-D20 (Pl. 2, Fig. 5).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900-33R-5, 129 cm; early Miocene, Zone NN1.

Occurrence. Rare to common in late Oligocene to early Miocene from ODP Holes 897C, 898A, 899B, and 900A.

Range. Zones NP25 to NN2. The LO observed in Zone NN2 is a good event that can be used to subdivide Zone NN2. The LO of C. pelliculathus occurs between the LO of H. recta and the LO of I. fusa.

Genus CHIASMOLITHUS Hay, Mohler, and Wade, 1966

Chiasmolithus altus Bukry and Percival, 1971
(Pl. 2, Figs. 19, 20)

Chiasmolithus medius Perch-Nielsen, 1971
(Pl. 2, Figs. 17, 18)

Chiasmolithus oamaruensis (Deflandre, 1954) Hay, Mohler, and Wade, 1966
(Pl. 2, Figs. 21, 22)

Genus CLAUSICOCCUS Prins, 1979

Clausicoccus fenestratus (Deflandre and Fert, 1954) Prins, 1979
(Pl. 3, Figs. 1-7)

Clausicoccus obrutus (Perch-Nielsen, 1971) Prins, 1979
(Pl. 3, Figs. 10, 11, 13-16)

Clausicoccus vanheckae (Perch-Nielsen, 1986) n. comb.

Cruciplacolithus vanheckae Perch-Nielsen, 1986, p. 835, pl. 1, figs. 1-8.

Remarks. This medium-sized species has a wide, porous central plate. In cross-polarized light, the extinction pattern gives the false impression of the presence of a cross-bars. C. vanheckae is distinguished from C. fenestratus by its greater number of perforations in the central area and by its extinction pattern. C. cribellus has a central porous plate supporting a very thin, slightly offset axial cross. Other Oligocene Clausicoccus have fewer central perforations.

Genus COCCOLITHUS Schwarz, 1894

Coccolithus pelagicus (Wallich, 1977) Schiller, 1930
(Pl. 4, Figs. 7, 8, 21)

Coccolithus sp. 1
(Pl. 4, Figs. 10-13)

Remarks. This elliptical to subelliptical placolith consists of two incompletely developed shields connected by a thick, high inner wall surrounding a very large, open central area. In cross-polarized light, the rim exhibits a faint striated extinction pattern. The collar is bright. In phase contrast light, the collar appears thick and high. The placolith size measures from 6 to 13 µm.

These forms may represent a proto-coccolith ring tube of Coccolithus pelagicus. According to Kleijne (1990), their occurrence in high abundance may result from the very rapid successive production of coccoliths. The presence of malformed specimens may be related to changes in the environment (temperature, salinity, or nutrient availability).

They are rare in the early Miocene and rare to few in the middle to late Miocene.

Genus CORONOCYCLUS Hay, Mohler, and Wade, 1966

Coronocyclus aff. C. prionion
(Pl. 5, Figs. 24-27)

Coronocyclus nitescens (Kamptner, 1963)
(Pl. 5, Figs. 18-23)

Genus CRENALITHUS Roth, 1973

Crenalithus doronocoides (Black and Burns, 1961) Roth, 1973
(Pl. 7, Fig. 32)

Genus CRYPTOCOCCOLITHUS Gartner, 1992

Cryptococcolithus mediaperforatus (Varol, 1991) n. comb.
(Pl. 2, Figs. 13-16)

Birkelundia mediaperforata Varol 1991, p. 221, fig. 7 (17-20).

Cryptococcolithus takayamae Gartner 1992, p. 330, pl. 2, figs. 3a, b.

Remarks. Cryptococcolithus mediaperforatus has a nonbirefringent proximal and distal shield. The inner collar typically has a narrow elliptical outline and exhibits faint birefringence. Only rare specimens in upper Miocene Zone NN11 have the diagnostic central perforation. C. mediaperforatus is differentiated from similar size C. premacintyrei by its two non-birefringent shields and by the unique shape of its collar.

Most forms lack the central plate. The same feature is observed among the Calcidiscus species with a large central opening. Calcidiscus carlae (Pl. 1, Figs. 19 and 20) is a form of C. tropicus where the central plate is preserved.

Genus CYCLICARGOLITHUS Bukry 1971

Cyclicargolithus abisectus (Müller, 1970) Wise, 1983
(Pl. 7, Figs. 5, 6)

Remarks. Circular to subcircular placoliths with a small central opening, which lacks a grid, are included in this genus. Cyclicargolithus abisectus is restricted to forms larger than 10 µm. In cross-polarized light, C. abisectus exhibits a typical disjunct extinction line between the tube and the outer cycle of the shield. Forms smaller than 10 µm are included in C. floridanus. For this study, two groups of C. floridanus have been recognized based on the placolith size: forms smaller than 9 µm and forms between 9 to 10 µm. The typical disjunct extinction line of the large C. abisectus may be identifiable among the large C. floridanus.

Cyclicargolithus floridanus (Roth and Hay in Hay et al., 1967) Bukry, 1971
(Pl. 7, Figs. 7, 8)

Genus DISCOASTER Tan, 1927

Discoaster aulakos Gartner, 1967
(Pl. 6, Fig. 3)

Discoaster asymmetricus Gartner, 1969
(Pl. 6, Fig. 27)

Discoaster bellus Bukry and Percival, 1971
(Pl. 6, Figs. 29, 30)

Discoaster cf. D. bellus
(Pl. 6, Fig. 28)

Remarks. This Discoaster has pointed, slightly bent rays similar to Discoaster bellus. The tips of the rays appear bright in phase contrast light. The central area differs from D. bellus by being slightly larger and with a small proximal knob. Discoaster cf. D. bellus differs from Discoaster quinqueramus var. A by lacking the small stellate knob on the distal side.

Discoaster bollii Martini and Bramlette, 1963
(Pl. 6, Fig. 13)

Discoaster cf. D. bollii

Eu-discoaster cf. E. bollii Theodoridis, 1984, p. 166, pl. 33, figs. 6, 7.

Remarks. The forms included in this group are differentiated from D. bollii by having longer rays and a relatively smaller central area. A knob is present on both proximal and distal sides. Discoaster cf. D. bollii is restricted to the middle Miocene and occurs from the middle Miocene Zones NN6 to NN8. Its FO is placed just above the FO of T. rugosus. The top of its range overlaps the range of D. bollii.

Discoaster braarudii Bukry, 1971
(Pl. 6, Fig. 23)

Discoaster broweri Tan, 1927 emend. Bramlette and Riedel, 1954
(Pl. 6, Figs. 24, 32)

Discoaster deflandrei (Bramlette and Riedel, 1954) var. nodosus n. var.
(Pl. 6, Figs. 5, 6)

Remarks. This large Discoaster is distinguished from Discoaster deflandrei deflandrei by the position of a pair of lateral nodes on the arms. The pair of nodes are completely separated from the terminal bifurcation, as are the nodes in Discoaster tanii nodifer. Intermediate forms (Pl. 6, Fig. 6), with the pair of nodes still at the level of the bifurcation, are also observed. This group of large discoasters with a large central area have a very short range restricted to the highstand of the third-order sequence TB1.4 (upper Zone NN1 to lower Zone NN2). They also co-occur with the first occurrence peak of D. druggii (Pl. 6, Fig. 7) in the early Miocene. The diameter measures between 14 to 18 µm.

Discoaster druggii Bramlette and Wilcoxon, 1967
(Pl. 6, Fig. 7)

Discoaster extensus Hay, 1967
(Pl. 6, Fig. 4)

Discoaster kugleri Martini and Bramlette, 1963
(Pl. 6, Fig. 12)

Discoaster micros Theodoridis, 1984 n. comb.
(Pl. 6, Figs. 9, 10)

Eu-discoaster micros Theodoridis 1984, p. 170—171, pl. 36, figs. 1—3.

Remarks. The morphologic differences introduced by Theodoridis (1984) between Helio-discoaster (straight sutures) and Eu-discoaster (curved sutures) is not followed here. Discoaster micros has a relatively large central area, short bifurcated arms, and a low proximal knob. According to Theodoridis (1984) Discoaster micros is restricted to the E. kugleri Subzone (= Martini's Zone NN7). The forms observed at Site 900A are very similar to the holotype but have been recorded in the middle of Zone NN11. This Discoaster has a diameter between 5 and 6 µm.

Discoaster musicus Stradner, 1959
(Pl. 6, Fig. 11)

Discoaster obtusus Gartner, 1967
(Pl. 6, Fig. 1)

Discoaster prepentaradiatus Bukry and Percival, 1971
(Pl. 6, Fig. 20)

Discoaster quinqueramus (Gartner, 1969) var. A n. var.
(Pl. 6, Fig. 31)

Remarks. Discoaster quinqueramus var. A is differentiated from Discoaster quinqueramus by lacking a well-developed polygonal knob on the distal side. The FO and LO of D. quinqueramus var. A is used in this study to define the Zone NN11. Forms of Discoaster quinqueramus with a prominent stellate distal knob have not been observed at Holes 897C and 900A. Their absence may be due to some ecological exclusion, but there is no clear evidence to explain the absence of central knob.

Discoaster surculus Martini and Bramlette, 1963
(Pl. 6, Fig. 22)

Discoaster tamalis Kamptner, 1967
(Pl. 6, Figs. 25, 26)

Discoaster variabilis Martini and Bramlette, 1963 (5 ray asymmetric)
(Pl. 6, Fig. 19)

Remarks. Most of the five rays of Discoaster variabilis are slightly asymmetrical and do not have well-developed depressions around the center. Only rare forms (Pl. 6, Fig. 18) with five symmetrical rays exhibit a distal side with well-developed depressions. Therefore the FO of Discoaster prepentaradiatus (Pl. 6, Fig. 20) (forms without a developed central area), is not easily identifiable because many intergrading forms exist.

Genus ERICSONIA Black, 1964

Ericsonia formosa (Kamptner, 1963) Haq, 1971
(Pl. 4, Figs. 14-17)

Ericsonia detecta n. sp.
(Pl. 4, Figs. 1-6)

Diagnosis. An elliptical species of Ericsonia with a thin margin composed of two unequal shields; the proximal shield being much smaller or undeveloped. The central opening is large and open.

Description. The distal shield is composed of 30 to 34 slightly imbricated elements. The proximal shield has one fourth to one fifth the dimension of the distal shield and is composed of about the same number of elements. A very thin tube connects the two shields. In cross-polarized light, the distal shield is slightly birefringent and striated. The proximal shield and the inner cycle (tube) are bright. In phase contrast light, both shield appear dark.

Size. 5 to 7 µm (holotype: 5.3).

Differentiation. The rim margin is very similar to other species of the genus Ericsonia, but E. detecta lacks the typical plate elements filling the central area. E. detecta is differentiated from species of the genus Coccolithus by its very narrow proximal shield and by its large central opening. Its consistent occurrence throughout the Oligocene-Miocene interval and its presence in samples which an excellent preservation clearly indicate that E. detecta represents a separate species among the genus Ericsonia. E. detecta is differentiated from Ericsonia sp. 1 by its elliptical outline.

Derivation of name. From Latin detectus, unroof.

Holotype. FSU-F140 (Pl. 4, Fig. 1); FSU-FO53-D24 (Pl. 4, Fig. 2); FSU-FO53-D25 (Pl. 4, Fig. 3).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900-33R-5, 129 cm; early Miocene, Zone NN1.

Occurrence. Rare to common in Oligocene to Miocene sediments from ODP Holes 897C, 898A, 899B, and 900A. The FO is observed at Hole 897C in the upper part of Zone NP22 and at Holes 899B, 900A, in the lower part of Zone NP23. E. detecta occurs throughout the whole Miocene.

Ericsonia sp. 1
(Pl. 4, Fig. 20)

Remarks. This is a form similar to E. detecta, but having a distinct circular outline. Ericsonia sp. 1 has a large, open central area with a bright inner wall and a dark distal shield. It occurs from the Oligocene Zone NP22 to the lower part of Zone NP25. The diameter of this form is between 6 to 8 µm

Genus GEMINILITHELLA Backman, 1980

Geminilithella bramlettei (Hay and Towe, 1962) Varol, 1989a
(Pl. 4, Figs. 18, 19)

Cyclolithus bramlettei Hay and Towe, 1962, p. 500, pl. 5, fig. 6; pl. 7, fig. 2.

Cydococcolithina protoannula Gartner, 1971, p., pl. 5, figs 1a-c, 2.

Geminilithella bramlettei (Hay and Towe, 1962) Varol, 1989a, p. 296, pl. 1, figs. 22-24; pl. 3, figs. 41-42.

Remarks. C. protoannula is placed in synonymy with G. bramlettei. The holotype of C. protoannula (distal view) has two nearly equal-sized shields and a large central opening. This latter form is similar to the holotype of C. protoannula (proximal view).

Geminilithella rotula (Kamptner, 1956) Backman, 1980
(Pl. 5, Figs. 3, 8-11)

Genus HAYELLA Gartner, 1969

Hayella aperta Theodoridis, 1984 (elliptical)

Remarks. In cross-polarized light, this elliptical form has a large, striated shield surrounding a large central opening. The central tube exhibits a bright, diffused extinction pattern. Elliptical forms observed at Hole 900A are similar to the elliptical specimens illustrated by Theodoridis (1984, pl. 3, figs. 5, 6). The holotype of H. aperta has a distinct circular outline (Theodoridis, 1984, pl. 3, fig. 3). Elliptical forms of H. aperta are observed in early Miocene Zones NN1 to NN2 in Hole 900A.

Genus HELICOSPHAERA Kamptner, 1954 emend Theodoridis, 1984

Helicosphaera ampliaperta Bramlette and Wilcoxon, 1967
(Pl. 10, Figs. 1-3)

Helicosphaera bramlettei Müller, 1970
(Pl. 9, Figs. 16)

Helicosphaera aff. H. carteri (Wallich, 1877) Kamptner, 1954
(Pl. 8, Figs. 21-24; Pl. 10, Figs. 14, 15)

Remarks. This medium-sized Helicosphaera has two distinct openings aligned with the longer axis of the shield. The flange is rounded and terminates by a small inner crescent-shaped expansion along the side of the shield. The bar is in optical continuity with the rim and separates two openings. This helicolith measures between 8 to 10 µm and has a short range restricted to Oligocene Zone NP23 to the early part of Zone NP24. In cross-polarized light, Helicosphaera aff. H. carteri exhibits the same intense birefringence as H. carteri and is distinguished from the latter by its smaller size, the larger openings and the abrupt termination of the flange.

Helicosphaera compacta Bramlette and Wilcoxon, 1967
(Pl. 9, Figs. 8-11)

Helicosphaera elongata Theodoridis, 1984
(Pl. 9, Figs. 15, 24-27)

Helicosphaera euphratis Haq, 1966 (<8.0 µm)

Remarks. This form of Helicosphaera has a small central opening almost filled by the bar. Because of the small size of the bar, it is difficult to differentiate the small form of H. intermedia, a species of Helicosphaera with a less inclined, sigmoidal-shaped bar. Both H euphratis and H. intermedia have a rounded flange that terminates gradually along the side of the shields. The LO of H. euphratis (<8.0µm) has been observed with the LO of large form of H. euphratis (Pl. 9, Figs. 3, 12-14) in the upper part of the early Miocene Zone NN2. This event occurs just below the last occurrence of Triquetrorhabdulus challengeri.

Helicosphaera gartneri Theodoridis, 1984
(Pl. 9, Fig. 19)

Helicosphaera intermedia Martini, 1965
(Pl. 9, Figs. 20-23)

Helicosphaera limasera n. sp.
(Pl. 10, Figs. 12, 13)

Helicosphaera aff. H. seminulum Bramlette and Wilcoxon, 1967, p. 106, pl. 5, figs. 11, 12.

Diagnosis. A medium-sized species of Helicosphaera with a small rounded flange and an open central area spanned by a normal oblique bar that is in optical discontinuity with the shield. The flange does not extend outside the shield and terminates gradually along the side of the shield.

Description. In cross-polarized light, this medium-sized Helicosphaera has an open central opening spanned by a thick oblique bar which is birefringent and in discontinuity with the shield. The bar forms a distinct angle with the shield which is between 30° and 40° to the short axis. The flange is smoothly rounded and has a faint to dark extinction pattern.

Size. 8 to 12 µm; specimen from Bramlette and Wilcoxon (1967): 10.3 µm.

Differentiation. H. limasera differs from H. seminulum by having an oblique bar without a longitudinal suture. H. limasera is differentiated from H. bramlettei by its rounded flange and its more inclined bar.

Derivation of name. From Latin limus, oblique, and sera, bar.

Holotype. UP-FO-D (Pl. 10, Fig. 12); UP-FO-D (Pl. 10, Fig. 13).

Type locality. ODP Site 897, Iberia Abyssal Plain.

Type level. ODP Sample 149-897C-47R-6, 6 cm; early Oligocene, Zone NP23.

Occurrence. H. limasera is found Oligocene sediments from Sites 897 and 898.

Range. Zone NP23 to lower part of Zone NP25.

Helicosphaera obliqua Bramlette and Wilcoxon, 1967
(Pl. 8, Figs. 16-20)

Helicosphaera paleocarteri Theodoridis, 1984
(Pl. 10, Figs. 4-6)

Helicosphaera perch-nielseniae Haq, 1971
(Pl. 8, Figs. 3, 12, 15)

Helicosphaera recta Haq, 1966
(Pl. 8, Figs. 1, 2, 4-11)

Helicosphaera reticulata Bramlette and Wilcoxon, 1967
(Pl. 9, Fig. 17)

Helicosphaera truempyi Biolzi and Perch-Nielsen, 1982
(Pl. 9, Fig. 18)

Helicosphaera wilcoxonii Gartner, 1971
(Pl. 9, Figs. 4-7)

Genus HOMOZYGOSPHAERA Deflandre, 1952

Homozygosphaera macropora (Deflandre in Deflandre and Fert, 1954) n. comb.

Discolithus macroporus Deflandre in Deflandre and Fert, 1954, p. 138, pl. 11, fig. 5.

Holodiscus macroporus (Deflandre in Deflandre and Fert, 1954) Roth, 1970, p. 866, pl. 11, fig. 6.

Remarks. Deflandre (1952) defined Homozygosphaera for monomorphic coccosphere composed of zygoliths. According to Kleijne (1991), the distal side of Homozygosphaera may be spanned by a bridge or by several arches The type species, Conusphaera spinosa, is a coccolith tube with a distal side spanned by a high bridge. Homozygosphaera macropora (new combination) is a tube coccolith spanned by arches or septae surrounding 9 to 14 holes.

Genus HUGHESIUS Varol, 1989b

Hughesius gizoensis Varol, 1989b
(Pl. 3, Figs. 12, 17, 18)

Hughesius gizoensis Varol, 1989b, p. 261, pl. 4, figs 9-13.

Remarks. H. gizoensis (form with two unicyclic shields and two central plates) has been grouped together with H. tasmaniae (form with central perforations) in the beginning of this study and therefore is not represented on the range charts. H. gizoensis has a consistent occurrence through the early middle Miocene. The holotype has been described from the upper Miocene and Varol (1989b) indicated an occurrence from Zones NN6 to NN11. H. gizoensis is present from Zone NN1 in the Iberia Abyssal Plain and overlaps the range of H. tasmaniae.

Hughesius tasmaniae (Edwards and Perch-Nielsen, 1975) n. comb.
(Pl. 3, Figs. 8, 9)

Ericsonia tasmaniae Edwards and Perch-Nielsen, 1975, p.481-482, pl. 20, figs. 5-12.

Remarks. As mentioned in the diagnosis by Edwards and Perch-Nielsen (1975), this small placolith lacks an inner distal cycle. Varol (1989b) described a new genus, Hughesius, for placoliths with two equal-sized unicyclic shields and a central area occupied by a variable number of plates. In cross-polarized light, the shields and central plate of Hughesius are non-birefringent. Species of Clausicoccus have a bright inner cycle in cross-polarized light. In phase contrast light, the shields and plates are dark and the central perforations are clearly identifiable. Forms with six or more perforations are included into H. tasnamiae. Forms with a central area occupied by two plates are identified as H. gizoensis. In the present study, forms with four perforations (Hughesius sp. from Varol, 1989b) have not been separated from H. tasmaniae, but are present at Sites 897, 898, 899 and 900. H. tasmaniae is present from the upper Oligocene Zone NP25 to the upper part of the early Miocene Zone NN2. Forms of Hughesius with four perforations have the same range. The LO of H. tasmaniae has been observed just earlier than the LO of Triquetrorhabdulus carinatus and is a reliable event that can be used alternatively to define the top of Zone NN2 when T. carinatus is missing.

Genus ILSELITHINA Stradner in Stradner and Adamiker, 1966

Ilselithina fusa Roth, 1970
(Pl. 12, Figs. 18-27)

Genus ISTHMOLITHUS Deflandre, 1954

Isthmolithus recurvus Martini, 1973
(Pl. 14, Figs. 1, 2)

Genus LANTERN ITUS Stradner, 1962

Lianternithus minutus Stradner, 1962
(Pl. 14, Fig. 6, 7)

Genus LITHOSTROMANION Deflandre, 1942

Lithostromanion operosum (Deflandre, 1954) Bybell, 1975
(Pl. 14, Fig. 5)

Genus MICRANTHOLITHUS Deflandre in Deflandre and Fert, 1954

Micrantholithus aequalis Sullivan, 1964
(Pl. 14, Fig. 13)

Genus MINYLITHA Bukry, 1973

Minylitha convallis Bukry, 1973
(Pl. 13, Figs. 27, 28)

Genus ORTHOZYGUS Bramlette and Wilcoxon, 1967

Orthozygus aureus (Stradner, 1962) Bramlette and Wilcoxon, 1967
(Pl. 14, Figs. 8, 9)

Genus PEDINOCYCLUS Bukry and Bramlette, 1971

Pedinocyclus larvalis (Bukry and Bramlette, 1969) Loeblich and Tappan, 1973
(Pl. 14, Figs. 14, 15)

Genus PEMMA Klump, 1953

Pemma papillata Martini, 1959
(Pl. 14, Figs. 10, 11)

Genus PERITRACHELINA Deflandre, 1952

Peritrachelina joidesa Bukry and Bramlette, 1968
(Pl. 14, Fig. 3)

Genus PONTOSPHAERA Lohmann, 1902

Pontosphaera anisotrema (Kamptner, 1956) Backman, 1980
(Pl. 12, Figs. 12, 13)

Pontosphaera callosa (Martini, 1969) Varol, 1982
(Pl. 12, Figs. 10, 11)

Pontosphaera longiforaminis (Báldi-Becke, 1964) n. comb.
(Pl. 12, Figs. 1-4)

Discolithus longiforaminis Báldi-Becke, 1964, p. 164, pl. 1, figs. 3, 3a, 3b.

Remarks. This species has a central plate composed of 15 to 18 radial elements. Only one complete cycle of perforations is present on the outer part of the plate. The other central perforations are slit-shaped pores between the radial elements and do not form an additional cycle of perforations. P. longiforaminis is distinguished from P. multipora by the shape and arrangement of its central perforations. P. multipora has rounded perforations (Pl. 12, Fig. 5) arrange in a complete cycle.

Pontosphaera multipora (Kamptner, 1948) Roth, 1970
(Pl. 12, Figs. 5-9)

Genus PYROCYCLUS Hay and Towe, 1962

Pyrocyclus orangensis (Bukry, 1971) Backman, 1980
(Pl. 7, Figs. 25-29)

Genus RETICULOFENESTRA Hay et al. 1966, emend Gallagher, 1989

Reticulofenestra bisecta (Hay, Mohler, and Wade, 1966) Roth, 1970 bisecta
(Pl. 7, Figs. 11, 12)

Reticulofenestra bisecta (Hay, Mohler, and Wade) Roth, 1970, p. 847, pl. 3, fig. 6.

Remarks. Forms of Reticulofenestra bisecta have been separated according to the size and the presence in the central area of a small plate or large plug. Two subspecies and one species are distinguished among this group: R. bisecta bisecta, R. bisecta filewiczii, and R. stavensis. The recognition of three forms presents some advantages for defining the Oligocene/Miocene boundary. R. bisecta bisecta (forms smaller than 10 µm) has its LO at the level of the LO of Sphenolithus ciperoensis. and can be use to define the Oligocene/ Miocene boundary. R. stavensis (=R. bisecta bisecta larger than 10 µm) has its LCO slightly above the LO of Sphenolithus ciperoensis, in the lower part of Zone NN1. R. bisecta filewiczii (forms with a small central plate) are usually observed up to the lower part of Zone NN2, but its last consistent occurrence level occurs in the lower part of Zone NN1.

Reticulofenestra bisecta (Hay, Mohler, and Wade, 1966) Roth, 1970filewiczii Wise and Wiegand, 1983
(Pl. 7, Figs. 13, 14)

Reticulofenestra bisecta (Hay, Mohler, and Wade) Roth, 1970 filewiczii Wise and Wiegand in Wise 1983, p. 505, pl. 5, fig. 3, pl. 6, figs. 1-2.

Remarks. As for the other subspecies of Reticulofenestra bisecta, different last occurrence levels are recorded in Holes 897C, 898A, 899B, and 900A. On the base of the biostratigraphic data from Hole 899B, the last consistent occurrence of R. bisecta filewiczii is placed in the lower part of Zone NN1, but sporadic specimens are observed in Hole 897C and 898A up to the lower part of Zone NN2.

Reticulofenestra circus n. sp.
(Pl. 7, Figs. 3, 4)

Diagnosis. A medium-sized, subcircular species of Reticulofenestra with a thin collar and a medium-sized central opening having a quadrate outline. The central area is either vacant or closed by a grid.

Description. A medium-sized placolith with a subcircular outline having an axial ratio of about 1.05. The proximal shield is slightly smaller than the distal shield and has a thin collar (or tube cycle). The central opening appears quadrate and represents 25% to 30% of the total length of the coccolith.

Size. Diameter: 8-9 (8.2) µm.

Differentiation. R. circus is distinguished from other medium-sized Reticulofenestra by its subcircular outline, the presence of a thin collar, and by the typical quadrated-shape of its central opening. R. circus is differentiated from R. hillae by its smaller size and its subcircular outline, and from C. floridanus by its larger, quadrated central opening.

Derivation of name. From Latin circus, round.

Holotype. UP-FOA-D32 (Pl. 7, Fig. 3).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900A-50R-5, 6 cm.

Occurrences. Present to few in lower Oligocene sediments from ODP Holes 897C, 899B and 900A.

Range. Restricted to the early Oligocene: Zones NP22 to NP23. The LO of R. circus is a good event and is usually found with the LO of L. minutus or just above it.

Reticulofenestra daviesi (Haq, 1968) Haq, 1971
(Pl. 7, Fig. 23)

Reticulofenestra hampdensis Edwards, 1973
(Pl. 7, Fig. 24)

Reticulofenestra lockeri Müller, 1970
(Pl. 7, Figs. 19, 20)

Reticulofenestra haqii Backman, 1978
(Pl. 7, Figs. 17, 18)

Reticulofenestra moguntina Martini, 1988
(Pl. 7, Figs. 21, 22)

Reticulofenestra francofurtana Best and Müller, 1972, p. 107, pl. 1, fig. 2, pl. 2, fig. 17 (non pl. 1, fig. 1).

Reticulofenestra moguntina Martini, 1988, p.217, pl. 1, figs. 3-4.

Reticulofenestra producta (Kamptner, 1963) Wei and Thierstein, 1991
(Pl. 7, Fig. 33)

Reticulofenestra stavensis (Levin and Joerger, 1967) Varol, 1989b
(Pl. 7, Figs. 9, 10)

Coccolithus stavensis Levin and Joerger, 1967, p. 165, pl. 1, figs. 7a-d.

Reticulofenestra stavensis (Levin and Joerger, 1967) Varol 1989b, p. 261.

Remarks. Species of Reticulofenestra with a large central plug closing the central area are distinguished in this study according to the placolith length. Forms larger than 10 µm are included in Reticulofenestra stavensis and forms smaller than 10 µm are included in Reticulofenestra bisecta bisecta. On the basis of the biostratigraphic results of Hole 899B, the last consistent occurrence of R. stavensis is placed in the lower part of Zone NN1, at the same level as the last consistent occurrence of R. bisecta filewiczii.

Reticulofenestra umbilicus (Levin, 1965) Martini and Ritzkowski, 1968
(Pl. 7, Figs. 1, 2)

Genus RHABDOSPHAERA Haeckel, 1894

Rhabdosphaera procera Martini, 1969
(Pl. 10, Figs. 10, 11)

Genus SPHENOLITHUS Deflandre, 1952

Sphenolithus akropodus n. sp.
(Pl. 11, Figs. 1, 2, 4-11)

Sphenolithus sp. aff. S. distentus Okada 1990, p. 154, pl. 2, figs. 7, 8.

Sphenolithus sp. 1 Fornaciari et al., 1990, pl. 2, figs. 1-3.

Diagnosis. A large species of Sphenolithus with a long tapering apical spine, sometimes bifurcated, and a short proximal elements extending laterally to form a small basal part.

Description. This sphenolith has a short proximal shield and a long apical spine. About 8 to 10 thick, elongated elements form the apical spine, which may be curved or bifurcated at the top. In cross-polarized light and at 45° to the crossed nicols, the apical spine is completely bright. The extinction suture line of the base curves downward, separating the proximal basal elements which extend laterally as two pointed feet. At 0° to the crossed nicols, the apical spine is weakly birefringent.

Size. Length: 7 to 9 (8.5) µm; basal part: 2.5 to 3.5 (3.0) µm.

Differentiation. S. akropodus differs from S. distentus by its larger size, the presence of more developed basal elements, and by a more massive apical spine. In crossed-polarized light and at 45° to the nicols, the extinction pattern of the basal shield elements of S. akropodus form two bright, pointed feet. In S. distentus the proximal elements are almost parallel to the long axis of the sphenolith and form two bright, less developed, and more blocky feet. S. akropodus differs from S. predistentus by its curved extinction suture line and from S. ciperoensis by its relatively shorter proximal shield and its extinction suture line, which does not extend proximally.

Derivation of name. From Greek akros, highest point, and pous, foot.

Holotype. FSU-F165 (Pl. 11, Fig. 1); FSU-FO54-D26 (Pl. 11, Fig. 4); FSU-FO54-D25 (Pl. 11, Fig. 5); FSU-FO54-D27 (Pl. 11, Fig. 6).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900A-51R-6, 47 cm.

Occurrence. Present to rare in early Oligocene sediments from Sites 897, 899, and 900. The LO of S. akropodus is a reliable event and is observed at Site 900 just below the FO of S. ciperoensis.

Range. Early Oligocene Zones NP22 to NP23.

Sphenolithus aubryae n. sp.
(Pl. 11, Figs. 16-18)

Sphenolithus dissimilis Sphenolithus belemnos intergrade Rio, Fornaciari, and Raffi, 1990, pl. 12, figs. 2.

Diagnosis. A short, compressed species of Sphenolithus with a proximal shield, about 2/3 the total length. The proximal elements are parallel to the long axis of the sphenolith. The apical, multispinate spine is very short and composed of few elements which are radially arranged and bell-shaped.

Description. In cross-polarized light, and at 0° to the nicols, the narrow basal shield is birefringent. The extinction line forms an asymmetric cross with a basal shield nearly twice the height of the apical spine. At 45° to the crossed nicols, the short, multipartite apical spine is birefringent and the extinction suture line between the proximal shield and the apical spine is V-shaped. In phase contrast light, a large dark cavity is present at the center of the apical spine.

Size. Length: 3.5 to 4.5 µm (holotype: 4.1); basal part: 2.0 to 2.5 µm (2.4).

Differentiation. S. aubryae differs from S. belemnos by the structure and length of its apical spine and by the nearly parallel sides of its proximal shield. At 45°, S. belemnos has a longer and slender apical spine. S. aubryae is differentiated from S. dissimilis by its shorter apical spine formed by short, non parallel elements. S. dissimilis has a large, extended base.

Derivation of name. In honor of Professor Marie-Pierre Aubry, Laboratoire de Géologie du Quaternaire, CNRS Luminy, Marseille (France).

Holotype. FSU-FO43-D33 (Pl. 11, Fig. 16); FSU-FO43-D34 (Pl. 11, Fig. 17); FSU-FO43-D35 (Pl. 11, Fig. 18).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900A-29R-6, 23 cm.

Occurrence. Present to few in early Miocene sediments from Sites 897, 898, 899, and 900.

Range. Early Miocene Zones NN2 to NN3.

Sphenolithus belemnos Bramlette and Wilcoxon, 1967
(Pl. 11, Figs. 25, 27)

Sphenolithus calyculus Bukry, 1985
(Pl. 10, Figs. 24, 26, 27)

Sphenolithus capricornutus Bukry and Percival, 1971
(Pl. 11, Fig. 19)

Sphenolithus ciperoensis Bramlette and Wilcoxon, 1967
(Pl. 10, Figs. 22, 23, 25)

Sphenolithus cometa n. sp.
(Pl. 11, Figs. 22-24)

?Sphenolithus multispinatus Fornaciari et al., 1990, p. 254, pl. 3, figs. 1-3 (nomen nudum).

Diagnosis. A species of Sphenolithus with a short narrow base and a long diverging apical spine in which the elements are longitudinally divided to form three to four separated elongated spines that flare upwards.

Description. In cross-polarized light and at 0° to the nicols, the bright basal elements are slightly laterally extended, the apical spine is bipartite and diverging; at 45° to the nicols, the proximal shield and the lateral elements are faintly birefringent and the apical spine exhibits a decreasing birefringence from its base towards the three delicate spines (giving an aspect similar to a comet).

Size. Length: 5 to 7 µm (holotype: 5.3); basal part: 1.5 to 2.5 µm (2.0).

Differentiation. S. cometa differs from all other sphenoliths by its typical apical spine. S. dissimilis also possesses a spine formed by three elements, but they are not separated longitudinally as the apical elements of S. cometa. At 0° to the nicols, S. capricornutus differs from S. cometa by has a more diverging and thicker spine; at 45° to the nicols, the apical spine of S. cometa is birefringent.

Derivation of name. From Latin cometa, comet.

Holotype. FSU-FO50-D6 (Pl. 11, Fig. 22); FSU-FO50-D5 (Pl. 11, Fig. 23); FSU-FO50-D7 (Pl. 11, Fig. 24).

Type locality. ODP Site 898, Iberia Abyssal Plain.

Type level. ODP Sample 149-898A-24R-5, 24 cm.

Occurrence. Rare to few in early Miocene sediments from Sites 897, 898, 899, and 900. S. cometa has its FO in the lower part of Zone NN2 and its LO in the upper part of Zone NN2 at the FO of S. belemnos.

Range. Early Miocene Zone NN2.

Sphenolithus delphix Bukry, 1973
(Pl. 11, Figs. 20, 21)

Sphenolithus distentus (Martini, 1965) Bramlette and Wilcoxon, 1967
(Pl. 10, Figs. 18-21)

Sphenolithus orphanknollensis Perch Nielsen, 1971
(Pl. 10, Figs. 16, 17)

Sphenolithus predistentus Bramlette and Wilcoxon, 1967
(Pl. 11, Figs. 3, 12-15)

Genus SYRACOSPHAERA Lohmann, 1902

Syracosphaera lamina n. sp.
(Pl. 14, Figs. 21-22)

Diagnosis. A medium-sized species of Syracosphaera with a narrow, strongly convex rim and a very thin central plate formed by elongated radial laths supporting a small, hollow central stem.

Description. In cross-polarized light, the narrow rim exhibits a bicyclic, sigmoidal extinction pattern. The narrow inner rim cycle has a faint birefringence and the outer cycle is brightly birefringent. The central plate is non-birefringent and the central stem appears slightly bright. In phase contrast light, the outer rim cycle is dark and the inner one is bright. The stem appears dark and hollow.

Size. Length: 5 to 6 µm (holotype: length: 5.9; width: 4.7).

Differentiation. S. lamina differs from S. clathrata (Roth 1970) by its rim construction, its large central area, and by its central plate. S. lamina is differentiated from S. histrica and S. pulchra by its non-birefringent central plate, and by the presence of a stem. Syracosphaera? fragilis (Theodoridis, 1984) has a unicyclic rim extinction pattern and a birefringent central plate.

Derivation of name. From Latin lamina, thin plate.

Holotype. FSU-FO48-D25 (Pl. 14, Fig. 21); FSU-FO48-D27 (Pl. 14, Fig. 22).

Type locality. ODP Site 900, Iberia Abyssal Plain.

Type level. ODP Sample 149-900A-27R-2, 72 cm.

Occurrence. Rare to few in late Oligocene to early Miocene sediments from Sites 897, 898 and 899. At Site 900, S. lamina has an extended range to the upper Miocene Zone NN11.

Genus TETRALITHOIDES Theodoridis, 1984

Tetralithoides symeonidesii Theodoridis, 1984
(Pl. 12, Figs. 14-17)

Genus TRANSVERSOPONTIS Hay, Mohler, and Wade, 1966

Transversopontis obliquipons (Deflandre in Deflandre and Fert, 1954)

Hay, Mohler, and Wade, 1966
(Pl. 14, Fig. 16)

Genus TRIQUETRORHABDULUS Martini, 1965

Triquetrorhabdulus carinatus Martini, 1965
(Pl. 13, Figs. 17-21)

Triquetrorhabdulus challengeri Perch-Nielsen, 1977
(Pl. 13, Figs. 4-6)

Triquetrorhabdulus milowiii Bukry, 1971
(Pl. 13, Figs. 2, 3)

Triquetrorhabdulus rioi Olafsson, 1989
(Pl. 13, Figs. 13, 14)

Triquetrorhabdulus rugosus Bramlette and Wilcoxon, 1967
(Pl. 13, Figs. 15, 16, 22)

Triquetrorhabdulus serratus (Bramlette and Wilcoxon, 1967) Olafsson, 1989
(Pl. 13, Figs. 11, 12)

Genus UMBILICOSPHAERA Lohmann, 1902

Umbilicosphaera cricota (Gartner, 1967) Cohen and Reonhardt, 1968
(Pl. 5, Figs. 14, 15)

Umbilicosphaera sibogae foliosa (Kamptner, 1963) Okada and McIntyre, 1977
(Pl. 5, Figs. 12, 13)

Umbilicosphaera sp. (elliptical)
(Pl. 5, Figs. 16, 17)

Remarks. This large, subelliptical to elliptical species of Umbilicosphaera has a narrow rim and a very large central opening. No other elliptical Umbilicosphaera have been described in the literature for the Miocene interval. Umbilicosphaera huburtiana (Gaarder, 1970) also has an elliptical rim but is a living taxa which first occurs in the Pleistocene. Rare to few elliptical, thin rim Umbilicosphaera occur from late Miocene Zone NN11 to the early Pliocene Zone NN15.

Genus ZYGRHABLITHUS Deflandre, 1959

Zygrhablithus bijugatus (Deflandre in Deflandre and Fert, 1954) Deflandre, 1959
(Pl. 13, Figs. 1, 7)

Zygrhablithus sp. 1
(Pl. 13, Figs. 8-10)

Remarks. This form of Zygrhablithus has a distinct thin base and a long distal process consisting of four elongated blade-shaped elements. An opening (canal) is present from the base to the upper part of the distal process. In cross-polarized light, the thin base and the upper part of the distal process are bright. The four elongated arches of the distal process are not- or faintly birefringent. Zygrhablithus sp. 1 is differentiated from Z. bijugatus (Pl. 13, Fig. 1, 7) by its faint birefringence, and from Z. kerabyi, and Z. sileensis by its thinner basal base and its longer, narrow distal process. Zygrhablithus sp. 1 is a form similar to the Eocene Z. sagittus but differs by having a longer distal process. Zygrhablithus sp. 1 has been observed from the base of the late Oligocene Zone NP24 to the early Miocene Zone NN2.