Rosenthal, Y., Holbourn, A.E., Kulhanek, D.K., and the Expedition 363 Scientists
Proceedings of the International Ocean Discovery Program Volume 363
publications.iodp.org

Data report: Middle to Lower Miocene radiolarian biostratigraphy in the Western Pacific Warm Pool at IODP Expedition 363 Site U1490: preliminary results¹

Kenji M. Matsuzaki,^2, 3 Shin-ichi Kamikuri,⁴ and Takuya Sagawa⁵

¹Matsuzaki, K.M., Kamikuri, S., and Sagawa, T., 2023. Data report: Middle to Lower Miocene radiolarian biostratigraphy in the Western Pacific Warm Pool at IODP Expedition 363 Site U1490: preliminary results. In Rosenthal, Y., Holbourn, A.E., Kulhanek, D.K., and the Expedition 363 Scientists, Western Pacific Warm Pool. Proceedings of the International Ocean Discovery Program, 363: College Station, TX (International Ocean Discovery Program). https://doi.org/10.14379/iodp.proc.363.206.2023

²Atmosphere and Ocean Research Institute, University of Tokyo, Japan. kmatsuzaki@g.ecc.u-tokyo.ac.jp

³Also at Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Japan.

⁴Faculty of Education, Ibaraki University, Japan.

⁵Institute of Science and Engineering, Kanazawa University, Japan.

Abstract

Because the western equatorial Pacific Ocean is famous for its calcareous oozes, various biostratigraphic studies on planktonic foraminifers and calcareous nannofossils have been conducted in this region. As a result, western equatorial Pacific Ocean–based studies have established that the tropical Pacific region drives the atmospheric circulation by high seawater temperature, strongly influencing the global climate. Based on this finding, a number of sites were cored in this region during International Ocean Discovery Program (IODP) Expedition 363. Shipboard results unexpectedly revealed that radiolarians are abundant and well preserved in sediment from Eauripik Rise Site U1490 between 220 and 350 m core depth below seafloor, Method A (CSF-A), within an interval of calcareous ooze composed primarily of calcareous nannofossils and foraminifers. Paleomagnetic reversal event and calcareous nannofossil and planktonic foraminiferal bioevents suggested that the interval from 220 to 350 m CSF-A corresponded to the Middle to Early Miocene. This study investigated radiolarian assemblages and the biostratigraphy of core catcher samples obtained from Hole U1490A between 250 and 350 m CSF-A. Notably, the last occurrence (LO) of Artophormis gracilis (Riedel) was confirmed at ~338 m CSF-A, demonstrating that the base of the site is older than 22.6 Ma in age. Additionally, the first occurrence (16.9 Ma) and LO (13.9 Ma) of Calocyclas costata Riedel were identified at 246.7 and 227.8 m CSF-A, respectively, and the LO of Didymocyrtis prismatica (Haeckel), indicating an age of 17.7 Ma, was recorded at 258.5 m CSF-A. We also calculate preliminary sedimentation rates based on the Early Miocene radiolarian biostratigraphy and provide taxonomic notes on radiolarian species.

1. Introduction

International Ocean Discovery Program (IODP) Site U1490 is located at the northern part of the Eauripik Rise (a stable ridge separating the East and West Caroline Basins). The site is situated at 05°48.95′N, 142°39.27′E at a water depth of 2341 m (Figure F1). Three holes were drilled at the site (Holes U1490A–U1490C), with Hole U1490A drilled the deepest, recovering almost 380 m of sediments spanning from recent to upper Oligocene (Rosenthal et al., 2018b). Notably, the sediments collected from Hole U1490A contain calcareous microfossils (mainly nannofossils and foraminifers), siliceous microfossils (radiolarians, diatoms, and sponge spicules), clay minerals, and volcanic ash (Rosenthal et al., 2018b).

Based on variations in the relative abundance of the major components cited above and relying on a combination of visual core description, microscopic examination of smear slides, scanning electron microscopy, magnetic susceptibility, natural gamma radiation, and color reflectance (Rosenthal et al., 2018a), the lithology of the sediment collected from Hole U1490A was divided into three subunits (IA–IC). Subunit IA is about 185 m thick and includes a sequence of Upper Miocene to recent foraminifer-rich nannofossil ooze with small amounts of clay and siliceous microfossils (Figure F2) (Rosenthal et al., 2018b). Subunit IB is about 78 m thick (185–263 m core depth below seafloor, Method A [CSF-A]) (Figure F2). In this subunit, clay minerals are a significant component of the sediment, with increasing abundances downhole spanning the Middle to Lower Miocene (Rosenthal et al., 2018b). It was also observed that although the primary lithology in Subunit IB is clay-rich foraminifer-nannofossil ooze, siliceous microfossils such as sponge spicules and radiolarians are also important components of Subunit IB sediment (Rosenthal et al., 2018b). Subunit IC is about 124 m thick (263–387 m CSF-A) and spans the upper Oligocene to Lower Miocene. Although the uppermost 10 m of Subunit IC is composed of greenish radiolarian-rich nannofossil ooze, the remainder of the subunit is radiolarian-rich chalk (Rosenthal et al., 2018b).

Calcareous nannofossil and planktonic foraminifer biostratigraphy, together with magnetostratigraphy, was conducted shipboard to date the collected sediment (Rosenthal et al., 2018a). Investigations revealed that the sediment records a magnetic signal for all of Subunit IB, but little or no magnetic signal was found in Subunits IA and IC. Thus, the preliminary age model of Subunits IA and IC mainly relied on calcareous microfossil biostratigraphy. However, because the Middle Miocene sediment is surprisingly radiolarian rich, this provided an opportunity to examine radiolarian biostratigraphy at Site U1490. Therefore, this study aims to report preliminary radiolarian biostratigraphic results based on radiolarian assemblages from core catcher samples obtained from Subunits IA–IC. The newly established radiolarian biostratigraphy can help refine the age-depth model of Hole U1490A, particularly for Subunit IC, which has no magnetostratigraphic tie points and only a few calcareous microfossil biostratigraphic tie points. We also provide taxonomic notes for the abundant radiolarian species encountered during our preliminary analysis. Overall, this study is preliminary and will be followed up by analyzing higher resolution samples from Site U1490 to refine the radiolarian biostratigraphy.

2. Materials and methods

Samples from Site U1490 were prepared following the procedures described by Sanfilippo et al. (1985) and Kamikuri (2017, 2022). The dried and weighed sediment samples were placed in a beaker with 15% H₂O₂ to remove organic materials, after which a 3%–5% solution of hydrochloric acid was added to remove the calcareous fraction from the sediment. Subsequently, after the samples were washed and sieved through a 45 µm mesh, the dried sample was scattered randomly on a glass slide. Next, Norland optical adhesive 60 was used as a mounting medium for a 24–36 mm cover glass. Preservation of the radiolarian tests was assessed based on the following criteria (Table T1):

• Good (G): only minor fragmentation.
• Moderate (M): obvious fragmentation, but identification of species unimpaired.
• Poor (P): individual taxa exhibit considerable fragmentation, causing impossible identification of some species.

Relative abundances of individual taxa were classified based on the systematic examination of 500 radiolarians per sample (Kamikuri, 2022):

• Abundant (A): >10%.
• Common (C): >5%–10%.
• Few (F): 1%–5%.
• Rare (R): <1%.

3. Results

3.1. Radiolarian biozones

Based on the biostratigraphically useful radiolarian taxa occurrences in Hole U1490A (Plates P1, P2, P3, P4, P5; see Appendix; Table T1), we apply the tropical biostratigraphic scheme of Riedel and Sanfilippo (1970, 1978), Sanfilippo and Nigrini (1998), and Kamikuri (2022) to identify six radiolarian interval zones: the Lychnocanoma elongata Interval Zone (RP22), Cyrtocapsella tetrapera Interval Zone (RN1), Stichocorys delmontensis Interval Zone (RN2), Stichocorys wolffii Interval Zone (RN3), Calocyclas costata Interval Zone (RN4), and Dorcadospyris alata Interval Zone (RN5). Additionally, six interval subzones similar to those of Kamikuri (2022) were identified: the Didymocyrtis prismatica Interval Subzone (RN3a), Trissocyclus stauroporus Interval Subzone (RN3b), Carpocanopsis cingulata Interval Subzone (RN4a), Dorcadospyris dentata Interval Subzone (RN4b), Didymocyrtis mammifera Interval Subzone (RN5a), and Calocyclas caepa Interval Subzone (RN5b).

3.1.1. Zone RP22: Lychnocanoma elongata Interval Zone (first identified by Riedel and Sanfilippo, 1970; amended by Riedel and Sanfilippo, 1978)

Definition: the top of this zone is defined by the first occurrence (FO) of C. tetrapera (Haeckel) (Figure F2). The base of this zone, although not identified at Site U1490 at least in core catcher material, is defined by the FO of L. elongata (Vinassa de Regny).

Interval: the base of Site U1490 at 382.8 m CSF-A is within this zone. The stratigraphic intervals assigned to this zone are between Samples 363-U1490A-43X-CC (380.06 m CSF-A) and 38X-CC (329.56 m CSF-A) (Table T2). During drilling of Core 43X, the extended core barrel (XCB) cutting shoe failed, resulting in the termination of drilling in Hole U1490A. Thus, the base of Site U1490 is within the L. elongata Interval Zone.

Important data: two other important bioevents were identified in this zone between Samples 363-U1490A-38X-CC and 39X-CC at a midpoint depth of 338.19 m CSF-A (Figure F2; Tables T1, T2): the last occurrence (LO) of Artophormis gracilis (Riedel) (22.6 Ma) and the FO of Didymocyrtis bassanii (Carnevale) (22.9 Ma).

Correlation and ages: the top of this zone is defined by the FO of C. tetrapera, which is typically located near the Chron C6C paleomagnetic reversal event (Figure F2). The upper L. elongata Interval Zone (RP22) corresponds to calcareous nannofossil Zones CNM1 (Backman et al., 2012) and NN1 (Martini, 1971) (Figure F2).

3.1.2. Zone RN1: Cyrtocapsella tetrapera Interval Zone (Riedel and Sanfilippo, 1978)

Definition: the base of this zone is defined by the FO of C. tetrapera (Figure F2), and the top of this zone is defined by the LO of Theocorythium annosa (Riedel).

Interval: stratigraphic intervals assigned to Zone RN1 are identified between Samples 363- U1490A-38X-CC (329.56 m CSF-A) and 35X-CC (308.71 m CSF-A) (Table T2).

Important data: three other important bioevents are identified in this zone. The FO of Didymocyrtis tubaria (Haeckel) (21.4 Ma) is situated between Samples 363-U1490A-35X-CC and 36X-CC at a midpoint depth of 312.52 m CSF-A (Figure F2; Tables T1, T2). The FO of Calocyclas serrata (Moore) (22.1 Ma) is identified between Samples 37X-CC and 38X-CC at a midpoint depth of 328.48 m CSF-A. Lastly, the FO of Cyrtocapsella cornuta (Haeckel), which is dated at 22.3 Ma, is found between Samples 36X-CC and 37X-CC at a midpoint depth of 321.87 m CSF-A.

Correlation and ages: this zone is defined by the FO of C. tetrapera and the LO of T. annosa and is typically correlated from the middle of Chron C6B to the Chron C6AA paleomagnetic reversal event (Figure F2). Investigations also revealed that the C. tetrapera Interval Zone (RN1) corresponds to the lower part of calcareous nannofossil Zone NN2 (Martini, 1971), as well as all of Zone CNM2 and the lower part of Zone CNM3 (Backman et al., 2012) (Figure F2).

3.1.3. Zone RN2: Stichocorys delmontensis Interval Zone (Riedel and Sanfilippo, 1978)

Definition: the base of this zone is defined by the LO of T. annosa (Riedel) (Figure F2), and the FO of S. wolffii Haeckel defines the top of this zone.

Interval: stratigraphic intervals assigned to this zone are identified between Samples 363-U1490A-35X-CC (308.90 m CSF-A) and 29F-CC (260.72 m CSF-A) (Table T2).

Important data: six other important bioevents were identified in this zone. First, the FO of S. delmontensis (Campbell and Clark) (20.7 Ma) and the LO of C. serrata (Moore) (20.5 Ma; Nigrini et al., 2006) are situated between Samples 363-U1490A-32X-CC and 33X-CC at a midpoint depth of 283.10 m CSF-A (Figure F2; Tables T1, T2). The FO of Didymocyrtis violina (Haeckel) (19.8 Ma), the LO of Phormocyrtis alexandrae O’Connor (19.0 Ma), and the LO of C. tetrapera (Haeckel) (18.9 Ma; Kamikuri, 2022) are identified between Samples 30F-CC and 31F-CC at a midpoint depth of 267.52 m CSF-A (Tables T1, T2). Additionally, the LO of Dorcadospyris ateuchus (Ehrenberg) (19.1 Ma) is recorded at 262.84 m CSF-A between Samples 29F-CC and 30F-CC.

Correlation and ages: the S. delmontensis Interval Zone (RN2) corresponds to the Chron C6AA and C6 paleomagnetic reversal event (Figure F2). This zone also corresponds to upper calcareous nannofossil Zone NN2 (Martini, 1971), as well as the upper part of Zone CNM3 and Zone CNM4 (Backman et al., 2012) (Figure F2).

3.1.4. Zone RN3: Stichocorys wolffii Interval Zone (Riedel and Sanfilippo, 1978)

Definition: the base of this zone is defined by the FO of S. wolffii Haeckel, and the top is defined by the FO of Calocyclas costata Riedel (Figure F2).

Interval: stratigraphic intervals are identified between Samples 363-U1490A-29F-CC (260.72 m CSF-A) and 27H-CC (251.4 m CSF-A) (Table T2).

Important data: four other important bioevents are identified in this zone: the FO of T. stauroporus Haeckel (18.0 Ma), which is situated between Samples 363-U1490A-28F-CC and 29F-CC at a midpoint depth of 258.36 m CSF-A (Figure F2; Tables T1, T2), the LOs of D. prismatica (Haeckel) (17.7 Ma) and Thamnospyris schizopodia (Haeckel) at 253.70 m CSF-A between Samples 27H-CC and 28F-CC (Figure F2; Tables T1, T2), and the LO of Cyrtocapsella elongata at 246.61 m CSF-A between Samples 26H-CC and 27H-CC.

Correlation and ages: the S. wolffii Interval Zone (RN3) corresponds to the Chron C6/C5C paleomagnetic reversal event (Figure F2). This zone also corresponds to upper calcareous nannofossil Zone NN3 and the lower part of Zone NN4 (Martini, 1971) and encompasses Zone CNM5 and the lower part of Zone CNM6 (Backman et al., 2012) (Figure F2).

Remarks: previous studies conducted in the Indian Ocean showed that it was possible to conduct precise correlations between data from radiolarians and calcareous nannofossils using Lower Miocene core sequences. Hence, based on precise new radiolarian data, Kamikuri (2022) divided the S. wolffii Interval Zone (RN3) into two subzones named the D. prismatica Interval Subzone (RN3a) and the T. stauroporus Interval Subzone (RN3b). Similarly, this study also identifies these subzones.

3.1.4.1. Subzone RN3a: Didymocyrtis prismatica Interval Subzone (Kamikuri, 2022)

Definition: the FO of S. wolffii Haeckel defines the base of this subzone, and the top is defined by the FO of T. stauroporus Haeckel (Figure F2).

Interval: stratigraphic intervals are identified between Samples 363-U1490A-29F-CC (260.72 m CSF-A) and 28F-CC (256.0 m CSF-A).

Correlation and ages: the T. stauroporus Interval Subzone (RN3a) corresponds to calcareous nannofossil Zones NN3 (Martini, 1971) and CNM5 (Backman et al., 2012) (Figure F2).

3.1.4.2. Subzone RN3b: Trissocyclus stauroporus Interval Subzone (Kamikuri, 2022)

Definition: the base of this subzone is defined by the FO of T. stauroporus Haeckel, and the top is defined by the FO of Calocyclas costata (Riedel) (Figure F2).

Interval: stratigraphic intervals are identified between Samples 363-U1490A-28F-CC (256.0 m CSF-A) and 26H-CC (241.8 m CSF-A) (Table T2).

Important data: the LO of Cyrtocapsella elongata (Nakaseko) at 246.61 m CSF-A between Samples 363-U1490A-26H-CC and 27H-CC is observed in this subzone.

Correlation and ages: the D. prismatica Interval Subzone (RN3b) corresponds to the lower part of calcareous nannofossil Zone NN4 (Martini, 1971) and the lower part of the Zone CNM6 (Backman et al., 2012) (Figure F2).

3.1.5. Zone RN4: Calocyclas costata Interval Zone (Riedel and Sanfilippo, 1970; amended by Riedel and Sanfilippo, 1978)

Definition: the base of this zone is defined by the FO of Calocyclas costata Riedel (Figure F2), and the top of this zone is defined by the evolutionary transition (ET) from D. dentata Haeckel to D. alata (Riedel) (Figure F2).

Interval: stratigraphic intervals are identified between Samples 363-U1490A-26H-CC (241.8 m CSF-A) and 25H-CC (232. 48 m CSF-A) (Table T2).

Important data: two other important bioevents are identified in this zone: the FO of L. elongata (Vinassa de Regny) and the LO of C. cingulata Riedel and Sanfilippo (18.9 Ma; Kamikuri, 2022) situated between Samples 363-U1490A-25H-CC and 26H-CC at a midpoint depth of 237.15 m CSF-A (Figure F2; Tables T1, T2).

Correlation and ages: the Calocyclas costata Interval Zone (RN4) corresponds to the Chron C5C/C5B paleomagnetic reversal event (Figure F2). This zone also corresponds to upper calcareous nannofossil Zone NN4 (Martini, 1971), as well as Zone CNM6 and the lower part of Zone CNM7 (Backman et al., 2012) (Figure F2).

Remarks: Kamikuri (2022) further divided the Calocyclas costata Interval Zone (RN4), relying on the LO of C. cingulata Riedel and Sanfilippo, into two subzones: the C. cingulata Interval Subzone (RN4a) and the D. dentata Interval Subzone (RN4b). Interestingly, this study identifies the LO of C. cingulata Riedel and Sanfilippo and the LO of S. diaphanes (Sanfilippo et al.,

1985) between Samples 363-U1490A-25H-CC and 26H-CC at a midpoint depth of 237.3 m CSF-A (Tables T1, T2). This depth corresponds to the top of the Calocycletta costata Interval Zone (RN4) at Site U1490, indicating that the sedimentation rates at around 240 m CSF-A were low and that analysis of additional samples between the core catcher samples is required to define the subzones accurately. Magnetostratigraphy for this time interval also suggested low sedimentation rates between 200 and 250 m CSF-A (Rosenthal et al., 2018b).

3.1.6. Zone RN5: Dorcadospyris alata Interval Zone (Riedel and Sanfilippo, 1970; amended by Riedel and Sanfilippo, 1978)

Definition: the base of this zone is defined by the ET from D. dentata Haeckel to D. alata (Riedel), and the top of this zone is defined by the FO of Diartus petterssoni (Riedel and Sanfilippo) (Figure F2).

Interval: the top of this zone could not be identified in Hole U1490A because of the poor preservation of radiolarians from samples shallower than Sample 363-U1490A-23H-CC. However, stratigraphic intervals assigned to this zone are still identified between Samples 25H-CC (232.48 m CSF-A) and 23H-CC (213.47 m CSF-A) (Table T2).

Remarks: previously, Kamikuri (2022) divided the D. alata Interval Zone (RN5) into two subzones, relying on the LO of Calocyclas costata (Riedel): the D. mammifera Interval Subzone (RN5a) and the C. caepa Interval Subzone (RN5b). Following this previous research, this study identifies the LO of Calocyclas costata Riedel between Samples 363-U1490A-24H-CC and 25H-CC at a midpoint depth of 227.73 m CSF-A (Tables T1, T2), with the D. mammifera Interval Subzone (RN5a) being the uppermost subzone.

3.1.6.1. Subzone RN5a: Didymocyrtis mammifera Interval Subzone (Kamikuri, 2022)

Definition: the base of this subzone is defined by the ET from D. dentata Haeckel to D. alata (Riedel), and the top is defined by the LO of Calocyclas costata (Riedel) (Figure F2).

Interval: stratigraphic intervals are identified between Samples 363-U1490A-25H-CC (232.48 m CSF-A) and 24H-CC (222.98 m CSF-A).

Important data: two other important bioevents are identified in this zone: the LOs of D. tubaria (Haeckel) and D. violina (Haeckel) situated between Samples 363-U1490A-24H-CC and 25H-CC at a midpoint depth of 227.73 m CSF-A (Figure F2; Tables T1, T2).

Correlation and ages: the D. mammifera interval Subzone (RN5a) corresponds to the Chron C5AD paleomagnetic reversal event (Figure F2). Investigations also revealed that the D. mammifera Interval Subzone (RN5a) corresponds to upper calcareous nannofossil Zone NN5 (Martini, 1971) and the upper part of Zone CNM7 (Backman et al., 2012) (Figure F2).

Remarks: the RN5a Interval Subzone lower boundary was defined by the ET from D. dentata to D. alata (Riedel and Sanfilippo, 1978). However, in this study, D. dentata was not observed in any of the 20 core catcher samples analyzed. Thus, we use the FO of D. alata instead. Nevertheless, analysis of additional samples from between core catchers will focus on the occurrence of D. dentata, despite D. dentata being rare or absent in some regions of the Indian Ocean (Kamikuri, 2022; S. Kamikuri, pers. comm., 2022).

3.1.6.2. Subzone RN5b: Calocyclas caepa Interval Subzone (Kamikuri, 2022)

Definition: the base of this subzone is defined by the LO of Calocyclas costata (Riedel) (Figure F2), and the top is defined by the FO of D. petterssoni (Riedel and Sanfilippo) (Figure F2).

Interval: Sample 363-U1490A-24H-CC (223.1 m CSF-A).

3.2. Updated Early Miocene age-depth model for Site U1490

A shipboard age-depth model was developed for Site U1490 using a combination of calcareous nannofossil and planktonic foraminifer biostratigraphy together with magnetostratigraphy. The magnetostratigraphy was particularly well defined between 197.0 (Subchron C5r.1r; ~11.056 Ma) and 263.30 m CSF-A (Chron C6n; 18.748 Ma), allowing for well-constrained sedimentation rates for the Miocene (Figure F3; Rosenthal et al., 2018b). However, deeper than 263.3 m CSF-A (18.748 Ma), no more paleomagnetic reversal events were identified and only a few planktonic foraminifer and calcareous nannofossil bioevents were recorded, resulting in poorer age constraint for the interval between 263 and 350 m CSF-A. Recently, Doyongan and Fernando (2021) reported a revised nannofossil biostratigraphy for the Miocene and thus improved the accuracy of the age model.

For further improvement of the age-depth model, we report 14 radiolarian bioevents between 263 and 350 m CSF-A for Hole U1490A that further constrain revised nannofossil biostratigraphy–based sedimentation rates for the Lower Miocene core sequences (Table T3).

There is generally good correspondence between radiolarian, calcareous nannofossil, and planktonic foraminifer bioevents for Hole U1490A (Figure F3), although there are some disparities with planktonic foraminifer ages between 250 and 265 m CSF-A (Figure F3). Such disparities correspond to changes in lithology, including a transition from clay-rich foraminifer-nannofossil ooze to radiolarian-rich nannofossil clay/radiolarian-rich chalk. However, because radiolarian ages fit well with paleomagnetic reversal events and calcareous nannofossil ages, we assume our preliminary results are reliable and allow us to compute preliminary sedimentation rates for depth intervals between 260 and 350 m CSF-A based on radiolarian bioevents. In lithologic Subunit IC, which is the oldest subunit (approximately between 350 and 270 m CSF-A), sedimentation rates were approximately 2.28 cm/ky (Figure F3). Sedimentation rates decreased at 270.3 m CSF-A to around 0.9 cm/ky, and this rate was maintained to 200 m CSF-A, which corresponds to lithologic Subunit IB (Figure F3). This decrease in sedimentation rate is close to the lithology transition from radiolarian-rich chalk with indurated ash/biosilica to radiolarian-rich nannofossil clay. These sedimentation rates could be improved in the future by additional refinement of the radiolarian biostratigraphy for the Lower Miocene using higher resolution samples.

4.  Acknowledgments

This work uses samples and data provided by the International Ocean discovery Program (IODP). This work was supported by Japan Society for the Promotion of Science (JSPS) Grant 19KK0089 awarded to Kenji M. Matsuzaki and in part by JSPS Grant 18H01279 awarded to Takuya Sagawa. We thank the IODP core curators at the Kochi Core Center (Japan) for providing samples as well as the IODP Expedition 363 science party. We also thank Drs. Ann Holbourn and Wolfgang Kuhnt for helpful advice. Lastly, we thank the editor, Dr. Denise Kulhanek, for reviewing and editing our manuscript and the reviewer, Dr. Johan Renaudie, for helpful and critical comments about radiolarian species taxonomy.

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Appendix

Taxonomic notes

We define brief synonymies for the encountered radiolarian species.

Order COLLODARIA Haeckel, 1882

Genus Polysolenia Ehrenberg, 1861

Polysolenia spinosa (Haeckel, 1861) sensu Matsuzaki (2021)

(Plate P1, figures 8, 11)

Collosphaera spinosa n. sp. Haeckel, 1861, p. 845.

Acrosphaera echinoides n. sp. Haeckel, 1887, p. 100.

Polyselonia spinosa (Haeckel); Matsuzaki et al., 2014, pl. 1, figs. 1, 2.

Polyselonia spinosa (Haeckel) group Kamikuri, 2019b, pl. 1, figs. 8, 10.

Polysolenia spinosa (Haeckel, 1861) sensu lato Matsuzaki, 2021, p. 2-2, pl. 1, fig. 2 (only).

Polysolenia sp. A

(Plate P1, figure 10)

Remarks. It differs from Polysolenia spinosa (Haeckel, 1861) sensu lato by having highly variable pore sizes.

Polysolenia glebulenta (Bjørklund and Goll, 1979)

(Plate P1, figure 9)

Collosphaera glebulenta n. sp. Bjørklund and Goll, 1979, pp. 1316, 1317, pl. 2, figs. 9–25.

Collosphaera glebulenta Bjørklund and Goll; Boltovskoy and Jankilevich, 1985, pl. 1, fig. 4.

Genus Siphonosphaera Müller, 1859

Siphonosphaera sp. A

(Plate P1, figure 13)

Genus Disolenia Ehrenberg, 1861

Disolenia sp. A

(Plate P1, figure 14)

Disolenia spp.

(Plate P1, figures 15, 16)

Order SPUMELLARIA Ehrenberg, 1876

Genus Spongasteriscus Haeckel, 1862

Spongasteriscus marylandicus Martin, 1904

(Plate P1, figures 1, 2)

Spongasteriscus marylandicus n. sp. Martin, 1904, p. 453, pl. 130, fig. 10.

Histiastrum martinianum n. sp. Carnevale, 1908, pp. 26, 27, pl. 4, fig. 11.

Spongasteriscus spp. Petrushevskaya and Kozlova, 1972, p. 529, pl. 20, fig. 12; pl. 21, figs. 6, 7.

Histiastrum martinianum Carnevale group Sanfilippo et al., 1973, p. 217, pl. 2, figs. 7, 8.

Stephanastrum sp. A

(Plate P1, figure 12)

Spongaster sp. A Kamikuri, 2019a, pl. 21, fig. 13.

Genus Dictyocoryne Ehrenberg, 1861

Dictyocoryne malagaense (Campbell and Clark, 1944) group

(Plate P1, figures 3–7)

Rhopalodictyum (Rhopalodictya) malagaense n. sp. Campbell and Clark, 1944, p. 29, pl. 4, figs. 4, 5.

Dictyocoryne malagaense Campbell and Clark; Kamikuri 2019b, pl. 9, fig. 5; Kamikuri, 2019a, pl. 19, figs. 1, 2.

Dictyocoryne malagaense (Campbell and Clark, 1944) group Matsuzaki, 2021, figs. 14, 15, 23.

Genus Thecosphaera Haeckel, 1882

Thecosphaera sp. A

(Plate P1, figure 17)

Thecosphaera dedoensis Nakaseko, 1971 group

(Plate P1, figure 24)

Thecosphaera dedoensis n. sp. Nakaseko, 1971, p. 61, pl. 2, figs. 2a, 2b.

Thecosphaera dedoensis Nakaseko; Motoyama, 1996, pl. 2, fig. 2; Kamikuri, 2019a, pl. 13, figs. 1–8.

Remarks. The morphology of T. dedoensis in Kamikuri (2019a) differs slightly from the holotype by having more numerous pores on the Equator. Thus, we propose here the name for such morphotypes as T. dedoensis group.

Genus Excentrodiscus Hollande and Enjumet, 1960

Excentrodiscus planangulus Renaudie and Lazarus, 2016

(Plate P1, figure 18)

Excentrodiscus planangulus n. sp. Renaudie and Lazarus, 2016, pp. 31–33, pl. 2, figs. 1A-3, A-6.

Genus Hexastylus Haeckel, 1882

Hexastylus aculeata (Campbell and Clark, 1944)

(Plate P1, figure 19)

Staurolonche (Staurolonchantha) aculeata Campbell and Clark, 1944, p. 13, pl. 2, figs. 2, 3.

Hexastylus aculeata (Campbell and Clark); Kamikuri, 2019a, pl. 12, figs. 3a, 3b.

Genus Stylatractona Haeckel, 1887

Stylatractona sp. A

(Plate P1, figures 20, 21)

Genus Heliodiscus Haeckel, 1862

Heliodiscus grottensis Stöhr, 1880

(Plate P1, figure 22)

Heliodiscus grottensis n. sp. Stöhr, 1880, p. 89, pl. 1, fig. 13.

Heliodiscus (Heliodiscetta) siculus Stoehr; Haeckel, 1887, p. 446.

Heliodrymus (Heliocladus) grottensis (Stoehr); Haeckel, 1887 p. 451.

Heliodiscus sp. A

(Plate P1, figure 23)

Genus Didymocyrtis Haeckel, 1862

Didymocyrtis prismatica (Haeckel, 1887)

(Plate P2, figures 1, 2, 4)

Pipettella prismatica n. sp. Haeckel, 1887, p. 305, pl. 39, fig. 6.

Pipettella prismatica Haeckel; Riedel, 1959, pp. 287, 288, pl. 1, fig. 1.

Cannartus prismaticus (Haeckel); Riedel and Sanfilippo, 1970, p. 520, pl. 15, fig. 1; Ling, 1975, p. 717, pl. 2, figs. 7, 8.

Didymocyrtis prismatica (Haeckel); Nigrini and Lombari, 1984, S45, S46, pl. 6, figs. 3a, 3b; Kamikuri et al., 2009, fig. 9A; Kamikuri, 2019b, pl. 6, figs. 4, 5.

Didymocyrtis tubaria (Haeckel, 1887)

(Plate P2, figures 3, 5)

Pipettaria tubaria n. sp. Haeckel, 1887, p. 339, pl. 39, fig. 15.

Cannartus tubarius (Haeckel); Riedel and Sanfilippo, 1970, p. 520, pl. 15, fig. 2; Sakai, 1980, p. 707, pl. 5, figs. 11a, 11b.

Didymocyrtis tubaria (Haeckel); Sanfilippo et al., 1985, p. 659, fig. 8.2; Sugiyama and Furutani, 1992, p. 201, pl. 16, fig. 1; Kamikuri et al., 2009, fig. 9B; Kamikuri, 2019b, pl. 6, figs. 6, 7.

Didymocyrtis bassanii (Carnevale, 1908)

(Plate P2, figures 6–8)

Cannartidium bassanii n. sp. Carnevale, 1908, p. 21, pl. 3, fig. 12.

Cannartus bassanii (Carnevale); Sanfilippo et al., 1973, p. 216, pl. 1, figs. 1–3.

Didymocyrtis bassanii (Carnevale); O’Connor, 1997, p. 112; Nigrini et al., 2006, p. 32, pl. P1, fig. 5; Kamikuri et al., 2009, fig. 9H; Kamikuri, 2019b, pl. 6, figs. 10, 12, 13.

Didymocyrtis cf. laticonus (Riedel, 1959)

(Plate P2, figure 9)

Cannartus laticonus n. sp. Riedel, 1959, pp. 291, 292, pl. 1, fig. 5.

Cannartus laticonus Riedel; Sakai, 1980, p. 705, pl. 3, figs. 7a, 7b, 8a, 8b.

Didymocyrtis laticonus (Riedel); Sanfilippo and Riedel, 1980, text-fig. 1e; Nigrini and Lombari, 1984, S53, S54, pl. 7, figs. 1a–1c; Sanfilippo et al., 1985, p. 658, figs. 8.5a, 8.5b; Kamikuri et al., 2009, fig. 9E; Kamikuri, 2019b, pl. 6, fig. 8.

Genus Stylodictya Ehrenberg, 1846

Stylodictya tenuispina Jørgensen, 1905 group sensu Matsuzaki (2021)

(Plate P2, figures 11–17)

Stylodictya tenuispina n. sp. Jørgensen, 1905, pp. 118, 119, pl. 10, fig. 39.

Stylodictya validispina Jørgensen; Kruglikova, 1974, p. 191, pl. 2, fig. 6 (only).

Stylodictya tenuispina Jørgensen group Matsuzaki and Itaki, 2019, pl. 2, figs. 24–27; Matsuzaki, 2021, figs. 4.16–4.19.

Stylodictya sp. A

(Plate P2, figure 10)

Genus Lithelius Haeckel, 1861

Lithelius hayesi (Lazarus et al., 2005)

(Plate P2, figure 18)

Prunopyle hayesi n. sp. Chen, 1975, p. 454, pl. 9, figs. 4, 5 (only).

Ommatodiscus haeckeli group Petrushevskaya, 1975, p. 572, pl. 32.

Larcopyle hayesi, Lazarus et al., 2005, p. 119, 120, pl. 11, figs. 1–8, 18–20.

Remarks. Specimens belonging to this species are characterized by well-pronounced whorl-arranged morphology although each whorl is thin. Thus, following the nomenclature in Matsuzaki et al. (2015), we propose to move such specimens into the Genus Lithelius Haeckel.

Lithelius haeckelispiralis Matsuzaki and Suzuki in Matsuzaki et al., 2015

(Plate P2, figures 12–15)

Lithelius spiralis n. sp. Haeckel, 1861, pp. 519, 520, pl. 27, figs. 6, 7.

Lithelius spiralis Haeckel; Tan and Su, 1982, p. 162, pl. 13, figs. 9–11.

Lithelius haeckelispiralis Matsuzaki and Suzuki nomen nov. Matsuzaki et al. 2015, pp. 37, 38, figs. 6.32, 6.33, 6.37.

Genus Larcopyle Dreyer, 1889 sensu Zhang and Suzuki, 2017

Larcopyle buetschlii Dreyer, 1889 sensu lato

(Plate P2, figure 16)

Larcopyle buetschlii n. sp. Dreyer, 1889, pp. 124, 125, fig. 70.

Larcopyle buetschlii Dreyer; Matsuzaki et al. 2015, p. 33, figs. 6.21–6.28; Matsuzaki, 2021, figs. 6.2–6.6.

Genus Phorticium sensu Zhang and Suzuki, 2017

Phorticium cf. scitulum Zhang and Suzuki, 2017 sensu lato

(Plate P2, figures 20, 21)

Phorticium scitulum n. sp. Zhang and Suzuki, 2017, pp. 45, 46, figs. 26.1–26.23.

Phorticium aff. scitulum Zhang and Suzuki; Matsuzaki and Itaki, 2019, pl. 3, figs. 9, 10, 12, 13; Matsuzaki, 2021, figs. 5.4, 5.6, 5.8, 5.10–5.12, 5.16.

Phorticium sp. A

(Plate P2, figure 19)

Order NASSELLARIA Ehrenberg, 1876

Genus Cyrtocapsella Haeckel, 1887

Cyrtocapsella cornuta (Haeckel, 1887)

(Plate P3, figures 1, 2)

Theocapsa (Theocapsura) darwinii n. sp. Haeckel, 1887, p. 1431, pl. 66, fig. 12.

Cyrtocapsa (Cyrtocapsella) cornuta n. sp. Haeckel, 1887, p. 1513, pl. 78, fig. 9.

Cyrtocapsella cornuta Haeckel; Riedel and Sanfilippo, 1970, p. 531, pl. 14, fig. 8.

Cyrtocapsella cornuta (Haeckel); Sakai, 1980, p. 709, pl. 8, figs. 8a, 8b; Sugiyama and Furutani, 1992, p. 208, pl. 17, fig. 11; Kamikuri et al., 2009, figs. 10X1, 10X2; Kamikuri, 2019b, pl. 10, figs. 5a, 5b; Kamikuri, 2019a, pl. 5, figs. 4a, 4b.

Cyrtocapsella tetrapera (Haeckel, 1887)

(Plate P3, figures 3, 4)

Cyrtocapsa (Cyrtocapsella) tetrapera n. sp. Haeckel, 1887, p. 1512, pl. 78, fig. 5.

Cyrtocapsa (Cyrtocapsella) cf. tetrapera Haeckel; Nakaseko, 1955, p. 119, pl. 11, figs. 7a, 7b.

Cyrtocapsella tetrapera Haeckel; Riedel and Sanfilippo, 1970, p. 530-531; Ling, 1975, p. 728, pl. 9, fig. 18; Sakai, 1980, p. 709, pl. 8, figs. 5, 6.

Lithocampe tetrapera (Haeckel); Petrushevskaya and Kozlova, 1972, p. 546, pl. 25, fig. 14.

Lithocampe radicula Ehrenberg; Suzuki et al., 2009, pl. 23, figs. 2a, 2b.

Cyrtocapsella tetrapera (Haeckel); Sanfilippo et al., 1973, p. 221, pl. 5, figs. 4–6; Nigrini and Lombari, 1984, N109, N110, pl. 23, fig. 5; Kamikuri et al., 2004, fig. 9.5; Kamikuri et al., 2009; figs. 10Z1, 10Z2; Kamikuri, 2019b, pl. 10, figs. 1a, 1b, 2a, 2b; Kamikuri, 2019a, pl. 5, fig. 5.

Cyrtocapsella elongata (Nakaseko, 1963)

(Plate P3, figure 9)

Theocapsa elongata n. sp. Nakaseko, 1963, p. 185, pl. 3, figs. 4, 5.

Cyrtocapsella elongata (Nakaseko); Sanfilippo and Riedel, 1970, p. 452, pl. 1, figs. 11, 12; Nigrini and Lombari, 1984, N105, N106, pl. 23, figs. 3a, 3b; Kamikuri, 2019b, pl. 10, figs. 3, 4; Kamikuri, 2019a, pl. 5, fig. 9.

Genus Stichocorys Haeckel, 1882

Stichocorys johnsoni (Caulet, 1986)

(Plate P3, figure 10)

Theoperid, gen. et sp. indet. Johnson, 1974, pl. 8, fig. 1.

Stichocorys johnsoni n. sp. Caulet, 1986, p. 851, pl. 6, figs. 5, 6.

Stichocorys? johnsoni Caulet group Sugiyama and Furutani, 1992, p. 210, pl. 17, fig. 4.

Stichocorys delmontensis (Campbell and Clark, 1944)

(Plate P3, figures 14–18)

Eucyrtidium (Eucyrtis) delmontense n. sp. Campbell and Clark, 1944, p. 56, pl. 7, figs. 19, 20.

Stichocorys delmontensis (Campbell and Clark); Riedel and Sanfilippo, 1970, p. 530, pl. 14, fig. 6; Nigrini and Lombari, 1984, N129, N130, pl. 25, fig. 4; Sugiyama and Furutani, 1992, p. 210, pl. 14, fig. 6; Motoyama, 1996, pl. 5, fig. 3; Matsuzaki and Itaki, 2019, pl. 8, fig. 1; Kamikuri et al., 2009, fig. 10Q; Kamikuri, 2019b, pl. 10, figs. 8a, 8b; Kamikuri, 2019a, pl. 5, fig. 7.

Eucyrtidium lineatum (Ehrenberg); Suzuki et al., 2009, pl. 38, figs. 15a–16c.

Stichocorys diaphanes (Sanfilippo et al., 1973)

(Plate P3, figures 11, 12)

Calocyclas coronata n. sp. Carnevale, 1908, p. 33, pl. 4, fig. 24.

Eucyrtidium diaphanes Sanfilippo and Riedel nomen nov. Sanfilippo et al., 1973, p. 221, pl. 5, figs. 12–14; Nigrini and Lombari, 1984, N113, N114, pl. 23, fig. 7; Kamikuri et al., 2009, fig. 10M.

Stichocorys diaphanes (Sanfilippo and Riedel); Kamikuri, 2019b, pl. 10, fig. 17.

Stichocorys wolffii Haeckel, 1887

(Plate P3, figure 13)

Stichocorys wolffii n. sp. Haeckel, 1887, p. 1479, pl. 80, fig. 10.

Stichocorys wolffii Haeckel; Riedel and Holm, 1957, pp. 92, 93, pl. 4, figs. 6, 7; Sanfilippo et al., 1985, p. 682, figs. 23.3a, 23.3b; Kamikuri et al., 2009, fig. 10N; Kamikuri, 2019b, pl. 10, figs. 10a, 10b.

Genus Lithocampe Ehrenberg, 1846

Lithocampe subligata Stöhr

(Plate P3, figures 19–21)

Lithocampe subligata Stöhr, 1880, p. 102, pl. 4, fig. 1.

Lithocampe subligata Stöhr group Petrushevskaya, 1975, p. 581, figs. 6–9, 12.

Genus Eucyrtidium Ehrenberg, 1846

Eucyrtidium cienkowskii Haeckel, 1887

(Plate P3, figures 32, 33)

Eucyrtidium cienkowskii n. sp. Haeckel, 1887, p. 1493, pl. 80, fig. 9.

Eucyrtidium cienkowskii Haeckel group Sakai, 1980, p. 710, pl. 7, figs. 8a, 8b, 9, 10; Sugiyama and Furutani, 1992, p. 208, pl. 14, figs. 3, 4, pl. 17, fig. 6; Kamikuri, 2019a, pl. 4, figs. 9–11.

Eucyrtidium sp. aff. inflatum Kling, 1973

(Plate P3, figure 34)

Genus Phormocyrtis Haeckel, 1887

Phormocyrtis alexandrae O’Connor, 1997

(Plate P3, figures 23, 31)

Eucyrtidium sp. B Sakai, 1980, p. 710, pl. 7, figs. 7a, 7b.

Eucyrtidium sp. Sugiyama and Furutani, 1992, p. 209, pl. 14, fig. 2.

Phormocyrtis alexandrae n. sp. O’Connor, 1997, pp. 110, 111, pl. 2, figs. 9–12; pl. 6, figs. 1–4, 6.

Genus Anthocyrtidium Haeckel, 1882

Anthocyrtidium achillis Haeckel, 1887

(Plate P4, figure 11)

Sethocorys achillis n. sp. Haeckel, 1887, p. 1301, pl. 62, fig. 8.

Anthocyrtidium achillis Haeckel; Caulet, 1979, p. 132, pl. 2, fig. 4.

Anthocyrtidium sp. A

(Plate P4, figure 12)

Genus Lamprocyclas Haeckel, 1882

Lamprocyclas sp. B sensu Kamikuri, 2019b

(Plate P3, figure 22)

Lamprocyclas sp. B Kamikuri, 2019b, pl. 14, figs. 4a, 4b.

Genus Calocyclas Ehrenberg, 1847

Remarks. Based on O’Dogherty et al. (2021), the genus Calocycletta Haeckel (1887) is a junior synonym of the genus Calocyclas Ehrenberg (1847). Thus, in this study we use the genus Calocyclas for species belonging to the genus Calocycletta Haeckel.

Calocyclas costata Riedel, 1959

(Plate P4, figures 1, 2)

Anthocyrtium (Anthocyrturium) flosculus n. sp. Haeckel, 1887, pp. 1277, 1278, pl. 62, fig. 19.

Calocyclas virginis Haeckel; Riedel, 1959, pp. 90–92, pl. 4, fig. 5.

Calocyclas costata n. sp. Riedel, 1959, pp. 296, 298, pl. 2, fig. 9.

Calocycletta costata (Riedel); Riedel and Sanfilippo, 1970, p. 535, pl. 14. fig. 12.

Calocyclas serrata (Moore, 1972)

(Plate P4, figure 3)

Calocycletta cf. virginis Haeckel; Riedel and Sanfilippo, 1970, pl. 14, fig. 11.

Calocycletta serrata n. sp. Moore, 1972, pp. 148, 150, pl. 2, figs. 1–3.

Calocycletta serrata Moore; Nigrini and Lombari, 1984, N159, N160, pl. 29, figs. 1a–1c; Riedel and Sanfilippo, 1986, pl. 6, figs. 12, 13; Palmer, 1981, pl. 1, fig. 3.

Remarks. Calocyclas serrata can be distinguished from other Calocyclas species by the presence of well-pronounced undulated wavy feet on the bottom of the abdomen.

Calocyclas virginis Haeckel, 1887

(Plate P4, figure 4)

Calocyclas (Calocycletta) virginis n. sp. Haeckel, 1887, pp. 1381, 1382, pl. 74, fig. 4.

Calocyclas virginis Haeckel; Riedel, 1954, pp. 172, 173.

Calocycletta virginis (Haeckel); Sanfilippo et al., 1973, p. 226, pl. 6, fig. 11; Sakai, 1980, p. 711, pl. 10, figs. 5a, 5b; Sanfilippo et al., 1985, p. 693, figs. 28.1a, 28.1b.

Calocyclas caepa (Moore, 1972)

(Plate P4, figure 10)

Calocycletta caepa n. sp. Moore, 1972, p. 150, pl. 2, figs. 4–7.

Calocycletta caepa Moore; Nigrini and Lombari, 1984, N153, N154, pl. 28, figs. 1a–1d; Sanfilippo et al., 1985, figs. 28.5a, 28.5b.

Calocyclas cladara (Sanfilippo and Riedel, 1992)

Calocycletta (Calocycletta) cladara Sanfilippo and Riedel, 1992, p. 30, pl. 2, figs. 12–16.

Genus Theocorythium Haeckel, 1887

Remarks. According to O’Dogherty et al. (2021), the genus Theocyrtis Haeckel, 1887 is a junior synonym of the genus Theocorythium Haeckel, 1887. Thus, in this study we refer to the genus Theocorythium Haeckel, 1887 all specimens belonging to the genus Theocyrtis Haeckel, 1887.

Theocorythium spongoconus (Kling, 1971)

(Plate P3, figures 5, 6)

Theocorys spongoconus n. sp. Kling, 1971, p. 1087, pl. 5, fig. 6.

Theocorys spongoconum Kling; Sakai, 1980, p. 711, pl. 8, fig. 14.

Theocorys spongoconus Kling; Nigrini et al., 2006, pp. 48, 49, pl. P4, figs. 19–21.

Theocorythium sp. A

(Plate P3, figure 7)

Theocorythium annosa (Riedel, 1959)

(Plate P4, figure 5)

Phormocyrtis annosa n. sp. Riedel, 1959, p. 294, pl. 2, fig. 7.

Theocyrtis annosa (Riedel); Riedel and Sanfilippo, 1970, p. 535, pl. 15, fig. 9; Nigrini et al., 2006, p. 50, pl. P5, fig. 14; Kamikuri et al., 2012, pl. 2, fig. 2.

Genus Artophormis Haeckel, 1882

Artophormis gracilis (Riedel, 1959)

(Plate P4, figure 6)

Artophormis gracilis n. sp. Riedel, 1959, p. 300, pl. 2, figs. 12, 13.

Artophormis gracilis Riedel; Moore, 1971, p. 742, pl. 5, figs. 10, 11; Sanfilippo et al., 1985, pp. 666, 667, figs. 12.2a, 12.2b, 12.2c; Nigrini et al., 2006, p. 26, pl. P3, figs. 20–22.

Cyrtophormis gracilis (Riedel); Petrushevskaya and Kozlova, 1972, p. 547, pl. 28, figs. 13–15.

Genus Siphocampe Haeckel, 1882

Siphocampe nodosaria (Haeckel, 1887) group

(Plate P3, figures 8, 30)

Lithomitra (Lithomitrella) nodosaria n. sp. Haeckel, 1887, p. 1484, pl. 79, fig. 1.

Lithomitra nodosaria Haeckel group; Petrushevskaya, 1975, p. 586, pl. 10, fig. 18.

Siphocampe nodosaria (Haeckel); Nigrini and Lombari, 1984, N191, N120, pl. 32, fig. 3.

Remarks. This species differs from Siphocampe arachnea Haeckel group mainly by having less pores in each segment.

Siphocampe sp. B

(Plate P3, figures 26, 27)

Genus Artostrobus Haeckel, 1887

Artostrobus cf. semazen Renaudie and Lazarus, 2012

(Plate P3, figure 35)

Artostrobus semazen n. sp. Renaudie and Lazarus, 2012, p. 44, pl. 4, figs. 5A, 5B, 10, 13.

Remarks. The specimen shown in Plate P3, figure 5, is very similar to Artostrobus semazen Renaudie and Lazarus but differs by having a nearly cylindrical abdomen instead of fusiform. Considering it may be an intraspecific variation, we propose the name Artostrobus cf. semazen Renaudie and Lazarus.

Genus Tricolocapsa Haeckel, 1887

Tricolocapsa sp. A

(Plate P3, figure 24)

Tricolocapsa sp. B

(Plate P3, figure 25)

Genus Carpocanopsis Riedel and Sanfilippo, 1971

Carpocanopsis cingulata Riedel and Sanfilippo, 1971

(Plate P4, figures 7, 8)

Carpocanopsis cingulatum n. sp. Riedel and Sanfilippo, 1971, p. 1597, pl. 2g, figs. 17–21; pl. 8, fig. 8.

Carpocanopsis cingulata Riedel and Sanfilippo; Sanfilippo et al., 1973, p. 224, pl. 6, figs. 5, 6; Nigrini and Lombari, 1984, N87, N88, pl. 21, fig. 4.

Genus Acrobotrys Haeckel, 1882

Acrobotrys disolenia (Haeckel, 1887)

(Plate P3, figure 29)

Acrobotrys disolenia n. sp. Haeckel, 1887, p. 1114, pl. 96, fig. 10.

Acrobotrys disolenia Haeckel; Kamikuri, 2019b, pl. 18, fig. 30.

Genus Dendrospyris Haeckel, 1882

Dendrospyris aff. bursa sensu Kamikuri, 2019a

(Plate P4, figures 19, 20)

Dendrospyris aff. bursa (Sanfilippo and Riedel); Kamikuri 2019a, pl. 7, figs. 12, 13.

Dendrospyris sp. A

(Plate P4, figure 21)

Dendrospyris sp. B

(Plate P4, figure 22)

Genus Tholospyris Haeckel, 1882

Tholospyris mammillaris (Haeckel, 1887)

(Plate P4, figure 13)

Dictyospyris (Dictyospyrissa) mammillaris n. sp. Haeckel, 1887, p. 1076, pl. 89, figs. 9, 10.

Tholospyris mammillaris (Haeckel); Nigrini and Lombari, 1984, N73, N74, pl. 20, figs. 3a, 3b.

Tholospyris spp.

(Plate P4, figures 14–18)

Genus Trissocyclus Haeckel, 1882

Trissocyclus stauroporus (Haeckel, 1887)

(Plate P4, figure 9)

Zygostephanus (Zygostephus) dissocircus n. sp. Haeckel, 1887, p. 971, pl. 93, fig. 1.

Zygostephanium dizonium n. sp. Haeckel, 1887, p. 973, pl. 93, fig. 3.

Trissocyclus (Tricyclarium) stauroporus Haeckel, 1887, p. 987, pl. 83, fig. 5.

Liriospyris stauropora (Haeckel); Goll, 1968, pp. 1431, 1432, pl. 175, figs. 1–3, 7, text-fig. 9.

Trissocyclus stauropora Haeckel; Petrushevskaya and Kozlova, 1972, p. 533, pl. 39, figs. 29–31; Sanfilippo et al., 1985, pp. 664, 665, figs. 11.1a, 11.1b, 11.1c.

Genus Dorcadospyris Haeckel, 1882

Dorcadospyris simplex (Riedel, 1959)

(Plate P5, figure 1)

Brachiospyris simplex n. sp. Riedel, 1959, pp. 293, 294, pl. 1, fig. 10.

Dorcadospyris simplex (Riedel); Riedel and Sanfilippo, 1970, p. 523, pl. 15, fig. 6; Nigrini and Lombari, 1984, N37, N38, pl. 18, fig. 3.

Dorcadospyris ateuchus Ehrenberg, 1874

(Plate P5, figure 2)

Ceratospyris ateuchus n. sp. Ehrenberg, 1874, p. 218.

Dorcadospyris ateuchus (Ehrenberg); Sanfilippo et al. 1985, p. 663, figs. 10.4a, 10.4b.

Dorcadospyris alata (Riedel, 1959)

(Plate P5, figure 5)

Brachiospyris alata n. sp. Riedel, 1959, pp. 293, 294, pl. 1, figs. 11, 12.

Dorcadospyris alata (Riedel); Riedel and Sanfilippo, 1970, p. 523, pl. 14, fig. 5; Sanfilippo et al., 1985, pp. 661, 662, fig. 10.7.

Genus Lychnocanoma Haeckel, 1887

Lychnocanoma elongata (Vinassa de Regny, 1900)

(Plate P5, figures 3, 4, 6, 8)

Tetrahedrina elongata n. sp. Vinassa de Regny, 1900, p. 243, pl. 2, fig. 31.

Lychnocanoma elongata (Vinassa de Regny); Sanfilippo et al. 1973, p. 221, pl. 5, figs. 19, 20; Kamikuri et al., 2012, pl. 2, fig. 11.

Lychnocanoma sp. A

(Plate P5, figures 7, 9)

Genus Thamnospyris Haeckel, 1882

Thamnospyris schizopodia (Haeckel, 1887)

Gorgospyris (Thamnospyris) schizopodia Haeckel, 1887, p. 1071, pl. 87, fig. 4.

Thamnospyris schizopodia (Haeckel); Petrushevskaya and Kozlova, 1872, pl. 38, fig. 2.