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СПИСАНИЕ НА БЪЛГАРСКОТО ГЕОЛОГИЧЕСКО ДРУЖЕСТВО, год. 78, кн. 1–3, 2017, с. 73–95REVIEW OF THE BULGARIAN GEOLOGICAL SOCIETY, vol. 78, part 1–3, 2017, p. 73–95

Family Globigerinidae Carpenter, Parker and Jones, 1862 from the Paleocene and Eocene in Lom Depression

Svetlozar SeferinovSofia University “St. Kliment Ohridski“, Department of Geology, Paleontology and Fossil Fuels, 1504 Sofia; E-mail: svetlozar_seferinov@yahoo.com

Семейство Globigerinidae Carpenter, Parker and Jones, 1862 от Палеоценската и Еоценската серия в Ломската депресия

Светлозар СефериновСофийски университет „Св. Климент Охридски“, Катедра Геология, палеонтология и изкопаеми горива, 1504 София

Abstract. The present article is the first part of two contributions presenting the taxonomy of planktonic foraminiferal assemblages from the Paleocene and Eocene in Lom depression. Taxonomical descriptions of 21 species belonging to 6 genera (Catapsydrax Bolli, Loeblich and Tappan, 1957 – 1 species, Paragloborotalia Cifelli, 1982 – 1 species, Pаrasubbotina Olsson, Hemleben, Berggren and Liu, 1992 – 3 species, Globigerina d’Orbigny, 1826 – 1 species, Subbotina Brotzen and Pozaryska, 1961 – 12 species, Globigerinatheka Brönnimann, 1952 – 3 species), 1 family (GLOBIGERINIDAE Carpenter, Parker and Jones, 1862) and 1 superfamily (GLOBIGERINOIDEA Carpenter, Parker and Jones, 1862) of Suborder GLOBIGERININA Delage and Hérouard, 1896 are given following the classification of Pearson et al. (2006). 12 species are first described in Bulgaria. The foraminiferal data were obtained from 376 samples of drill cuttings and core from 12 boreholes.

Keywords: planktonic foraminifera, taxonomy, Paleocene, Eocene, Lom depression.

Резюме. Настоящата статия е първата от две части, посветени на таксономията на планктонните фораминифери от Палеоценската и Еоценската серия в Ломската депресия. Представени са таксономични описания на 21 вида, принадлежащи на 6 рода (Catapsydrax Bolli, Loeblich and Tappan, 1957 – 1 вид, Paragloborotalia Cifelli, 1982 – 1 вид, Pаrasubbotina Olsson, Hemleben, Berggren and Liu, 1992 – 3 вида, Globigerina d’Orbigny, 1826 – 1 вид, Subbotina Brotzen and Pozaryska, 1961 – 12 вида, Globigerinatheka Brönnimann, 1952 – 3 вида), 1 семейство (GLOBIGERINIDAE Carpenter, Parker and Jones, 1862) и 1 надсемейство (GLOBIGERINOIDEA Carpenter, Parker and Jones, 1862) от подразред GLOBIGERININA Delage and Hérouard, 1896 съгласно систематиката на Pearson et al. (2006). Дванадесет от видовете се описват за първи път в България. Фораминиферните данни са получени от 376 проби от шлам и ядка от 12 сондажни разреза.

Ключови думи: планктонни фораминифери, таксономия, Палеоцен, Еоцен, Ломска депресия.

Introduction

The micropaleontological studies of planktonic fo-raminiferal assemblages in Lom depression began in the early 60’s of the 20th century by proving the pres-ence of the Paleocene (Danian) and Eocene (Lower, Middle, Upper) in some separate boreholes (Caneva, Vapcarova, 1961; Tsaneva, 1964; Vaptsarova, 1963, 1964). During the next decade specialized taxonomic research on the phylogenetic relationships and tax-onomy of some genera were published by Zaneva (1971a, b), Tsaneva (1975). Since then, with excep-

tion of Seferinov’s work (2013b), there are no other publications regarding the planktonic foraminifera in this region. This gap, as well as the fact that the stud-ies in the 20th century were published before the age of the Scanning Electron Microscopy (SEM), requires a new view of planktonic foraminiferal taxonomy ac-cording to the modern systematic.

This article is the first part of two contributions to-wards the goal of updating the taxonomy of planktonic foraminiferal assemblages obtained from the sedimen-tary rocks of the Paleocene–Eocene interval in Lom depression.

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Material and methods

The investigated foraminiferal collection, kept in the Museum of Paleontology and Historical Geology at Sofia University “St. Kliment Ohridski“, was ob-tained from 12 boreholes located in two separate parts of Lom depression (Fig. 1). The Paleogene sequences consist of five lithostratigraphic units: limestone-marl formation, clay-marl formation, Komarevo Formation, Avren Formation and marl-limestone formation. Their stratigraphic relationships are shown on Figure 2. The biostratigraphic subdivision and correlation of the Paleogene deposits in Lom depression have been al-ready presented by Seferinov (2013a).

All lithostratigraphic units contain planktonic fo-raminifera that are in different amounts and species diversity. The foraminiferal fauna is predominantly abundant, well preserved, with distinct morphology, and only the limestone intervals contains badly pre-served tests, often strongly damaged and assemblages are reduced in species diverstity, which shows partial dissolution and recrystallization.

A total number of 376 samples of well cuttings and core spaced at an average vertical interval of 10 m were studied. Their distribution in the borehole sec-tions is as follows: R-1 Asparuhovo (60 samples), R-3 Asparuhovo (36 samples), R-5 Asparuhovo (35 sam-ples), R-1 Dalgodeltsi (41 samples), R-1 Kovachitsa (21 samples), R-2 Komoshtitsa (17 samples), R-3 Komoshtitsa (33 samples), C-6 Oryahovo (35 sam-ples), C-7 Oryahovo (25 samples), C-8 Oryahovo (15 samples), C-10 Leskovets (19 samples) and C-11 Oryahovo (39 samples).

All samples were processed in the Geologigal en-terprise for laboratory investigation – laboratory of micropaleontology, following standard methods of

washing out through a 63-μm mesh sieve, and analyz-ing the residues for planktonic foraminifera. Picked specimens were mounted on SEM stubs and coated with gold. Scanning electron microscopy was con-ducted at Faculty of Chemistry at Sofia University “St. Kliment Ohridski“ with SEM JEOL JSM-5500.

Taxonomic descriptions

The present study revealed that the Paleocene and Eocene sediments in Lom depression contain abundant and diverse assemblages of planktonic foraminifera. Taxonomical descriptions of 21 species belonging to 6 genera (Catapsydrax Bolli, Loeblich and Tappan, 1957 – 1 species, Paragloborotalia Cifelli, 1982 – 1 species, Pаrasubbotina Olsson, Hemleben, Berggren and Liu, 1992 – 3 species, Globigerina dʼOrbigny, 1826 – 1 species, Subbotina Brotzen and Pozaryska, 1961 – 12 species, Globigerinatheka Brönnimann, 1952 – 3 species), 1 family (GLOBIGERINIDAE Carpenter, Parker and Jones, 1862) and 1 superfamily (GLOBIGERINOIDEA Carpenter, Parker and Jones, 1862) of Suborder GLOBIGERININA Delage and Hérouard, 1896 are given here following the classi-fication of Pearson et al. (2006). 12 species are de-scribed for the first time in Bulgaria.

Order FORAMINIFERIDA d’Orbigny, 1826Suborder GLOBIGERININA Delage and Hérouard, 1896Superfamily GLOBIGERINOIDEA Carpenter, Parker and Jones, 1862Family GLOBIGERINIDAE Carpenter, Parker and Jones, 1862Genus Catapsydrax Bolli, Loeblich and Tappan, 1957

Fig. 1. Location of the studied boreholes sections

Фиг. 1. Местоположение на изучените сондажни разрези

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Fig. 2. Correlation scheme for the spatial relationships of the Paleogene lithostratigraphic units in Lom depression1, clays; 2, marls; 3, clayey limestones; 4, sandy organogenic limestones; 5, clayey limestones with concretion

Фиг. 2. Корелационна схема за пространствените взаимоотношения между палеогенските литостратиграфски еди-ници в Ломската депресия1 – глини; 2 – мергели; 3 – глинести варовици; 4 – песъчливи органогенни варовици; 5 – глинести варовици с конкреции

Type species. Globigerina dissimilis Cushman and Bermudez, 1937.

Catapsydrax unicavus Bolli, Loeblich and Tappan, 1957(Plate I, 1–2)

1957. Catapsydrax unicavus sp. n.; Bolli et al., p. 37, pl. 7, fig. 9a–c, pl. 37, fig. 7a, b.

1962. Globigerinita unicavus unicavus (Bolli); Blow and Banner, p. 109, pl. 14, figs. M, N.

1975. Catapsydrax unicavus Bolli et al.; Stainforth et al., p. 328, fig. 149: 1, 2, 4, fig. 149: 5a–c [holotype re-illustrated]; fig. 149: 3a–b [reillustration of Blow and Banner, 1962, pl. 14, figs. M, N].

1991a. Catapsydrax unicavus Bolli et al.; Huber, p. 439, pl. 5, fig. 18.

1994. Catapsydrax unicavus Bolli et al.; Spezzaferri, p. 48, pl. 33, fig. 5a–c.

2006. Catapsydrax unicavus Bolli et al.; Pearson et al., p. 77, pl. 5.3, figs. 1–17 (pl. 5.3, figs. 1–3: SEMs of holotype of Catapsydrax unicavus Bolli).

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PLATE I ТАБЛИЦА I

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2015. Catapsydrax unicavus Bolli et al.; Pearson and Wade, p. 8, figs. 4.1a–5c.

Nomenclature. The holotype (Smithsonian Museum of Natural History, Washington, D. C., No. USNM P4216) was collected by Bolli from the Lower Miocene Cipero Formation of Trinidad, Globigerina ciperoensis zone, exposure on San Fernando by-pass road, Trinidad, B. W. I.Material. A few dozens of specimens with good and excellent preservation. Description. Cancellate, spinose, ruber/sacculifer-type wall texture, generally with heavy gametogenetic calcification. Test small in size, low trochospiral, with rounded periphery and 4 chambers in the final whorl. Chambers are globular, embracing, increasing rapidly in size with a small globular, slightly inflated bulla extending over the umbilicus. The bulla has one infra-laminal aperture with a continuous, thickened imper-

forate rim, sutures straight to slightly curved, moder-ately depressed.Remarks. The species is first described in Bulgaria.Discussion. Pearson et al. (2006) observed consider-able variability in the degree of chamber appression and bulla morphology. They acknowledge that future studies may well reveal more than one valid taxon within the broad concept of unicavus, especially as regards the larger, more loosely coiled morphotypes. Our specimens show similar variabilities in their mor-phological characteristics especially regarding the bulla.Distribution. Catapsydrax unicavus is known from the Lower Eocene zone Psеudohastigerina wilcoxen-sis/Morozovella velascoensis E2 (Berggren, Pearson, 2005; Wade et al., 2011) to the Lower Miocene. Cosmopolitan.Occurrence. Avren Formation: С-6 Oryahovo (253–345 m – E8–10, E11 zones); С-7 Oryahovo (230–

PLATE I

1, 2. Catapsydrax unicavus Bolli, Loeblich, and Tappan, 1957. С-6 Oryahovo, 253 m, sample 25, Avren Formation, Middle Eocene, E11 zone; 1, spiral view, SEM x 250; 2, umbilical view, SEM x 220. 3. Paragloborotalia nana (Bolli, 1957). С-6 Oryahovo, 256.50 m, sample 18, Avren Formation, Middle Eocene, E11 zone; umbili-cal view, SEM x 230.4. Parasubbotina eoclava Coxall et al., 2003. R-2 Komoshtitsa, 880 m, sample 86, clay-marl formation, Middle Eocene, E6-7 zone; umbilical view, SEM x 170.5, 6. Parasubbotina inaequispira (Subbotina, 1953). R-2 Komoshtitsa; 5, 1348 m, sample 138, limestone-marl formation, Lower Eocene, E5 zone, umbilical view, SEM x 170; 6, 970 m, sample 95, clay-marl formation, Lower Eocene, E6-7, spiral view, SEM x 180.7, 8. Parasubbotina varianta (Subbotina, 1953). С-6 Оryahovo, 465 m, sample 40, Komarevo Formation, Upper Paleocene, P4 zone; 7, spiral view, SEM x 180; 8, umbilical view, SEM x 190.9, 10. Globigerina officinalis Subbotina, 1953. С-6 Oryahovo, 250 m, sample 24, Avren Formation, Middle Eocene, E11 zone; 9, umbilical view, SEM x 150; 10, spiral view, SEM x 130.11, 12. Subbotina angiporoides (Hornibrook, 1965). С-6 Oryahovo; 11, 250 m, sample 24, Avren Formation, Middle Eocene, E11 zone; umbilical view, SEM x 230; 12, 250 m, sample 24, Avren Formation, Middle Eocene, E11 zone; spiral view, SEM x 230; 13. Subbotina corpulenta (Subbotina, 1953). R-3 Komoshtitsa, 840 m, sample 42, clay-marl formation, Lower Eocene, E7 zone; umbilical view, SEM x 120.

ТАБЛИцА I

1, 2. Catapsydrax unicavus Bolli, Loeblich, and Tappan, 1957. С-6 Оряхово, 253 m, проба 25, Авренска свита, Среден Еоцен, зона E11; 1 – спирална страна, SEM x 250; 2 – пъпна страна, SEM x 220. 3. Paragloborotalia nana (Bolli, 1957). С-6 Оряхово, 256,50 m, проба 18, Авренска свита, Среден Еоцен, зона E11; пъпна страна, SEM x 230.4. Parasubbotina eoclava Coxall et al., 2003. Р-2 Комощица, 880 m, проба 86, глинесто-мергелна задруга, Среден Еоцен, зона Е6-7; пъпна страна, SEM x 170.5, 6. Parasubbotina inaequispira (Subbotina, 1953). Р-2 Комощица, 5 – 1348 m, проба 138, варовиково-мергелна задруга, Долен Еоцен, зона E5; пъпна страна SEM x 170; 6 – 970 m, проба 95, глинесто-мергелна задруга, Долен Еоцен, зона Е6-7, спирална страна, SEM x 180.7, 8. Parasubbotina varianta (Subbotina, 1953). С-6 Оряхово, 465 m, проба 40, Комаревска свита, Горен Палеоцен, зона P4; 7 – спирална страна, SEM x 180; 8 – пъпна страна, SEM x 190.9, 10. Globigerina officinalis Subbotina, 1953. С-6 Оряхово, 250 m, проба 24, Авренска свита; Среден Еоцен, зона E11; 9 – пъпна страна, SEM x 150; 10 – спирална страна, SEM x 130. 11, 12. Subbotina angiporoides (Hornibrook, 1965). С-6 Оряхово, 11 – 250 m, пр. 24, Авренска свита, Среден Еоцен, зона E11, пъпна страна, SEM x 230; 12 – 250 m, проба 24, Авренска свита, Среден Еоцен, зона E11, спирална страна, SEM x 230;13. Subbotina corpulenta (Subbotina, 1953). Р-3 Комощица, 840 m, проба 42, глинесто- мергелна задруга, Долен Еоцен, зона E7; пъпна страна, SEM x 120.

Scale bar – 100 μm

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300 m – E8–10, E11 zones); С-11 Oryahovo (430 m – E11 zone); clay-marl formation: Р-2 Komoshtitsa (900 m – E6–7 zone); Р-3 Komoshtitsa (1100–1200 m – E7 zone). Lower–Middle Eocene.

Genus Paragloborotalia Cifelli, 1982Type species. Globorotalia opima subsp. opima Bolli, 1957.

Paragloborotalia nana (Bolli, 1957)(Plate I, 3)

1957b. Globorotalia opima nana subsp. n.; Bolli, p. 118, pl. 28, fig. 3a–c.

1978. Globorotalia opima nana Bolli; Toumarkine, p. 714, pl. 8, figs. 3–4.

1985. Globorotalia opima nana Bolli; Bolli and Saunders, p. 202, fig. 26: 16a–c (holotype reillustrated), fig. 26: 15, 17–20 (paratypes).

1993. Paragloborotalia nana (Bolli); Chaisson and Leckie, p. 176, pl. 8, figs. 10–11.

1995. Jenkinsella opima nana (Bolli); Poag and Commeau, p. 149, pl. 6, figs. 21–22.

2004. Paragloborotalia nana (Bolli); Pearson et al., p. 36, pl. 1, fig. 21.

2006. Paragloborotalia nana (Bolli); Pearson et al., p. 86, pl. 5.8, figs. 1–16 (pl. 5.8, figs. 1–3: SEMs of holo-type of Globorotalia opima nana Bolli).

Nomenclature. The holotype (Smithsonian Museum of Natural History, Washington, D.C., No. USNM P5661) is the specimen figured by Bolli (1957b) from the type section of the Globorotalia opima opima zone, Cipero type section, Trinidad. Material. Few very well preserved specimens.Description. Normal perforate, coarsely cancellate, sacculifer-type of wall, spinose in life, with sometimes heavy gametogenetic calcification. Test very low tro-chospiral, globular, quadrate in outline, with rounded axial periphery and flat spiral side. Chambers are glob-ular, inflated, embracing; 4 to occasionally 4½ in ulti-mate whorl, increasing slowly in size. Sutures slightly depressed, straight on both spiral and umbilical sides. Last 4 chambers comprise about three-quarters of the test size, ultimate chamber may be slightly reduced in size. Umbilicus very small sized, deep opening, some-times closed off by surrounding chambers. Aperture umbilical-extraumbilical, low arch, bordered by a nar-row, often thickened, continuous lip.Remarks. The species is first described in Bulgaria.Discussion. It tends to be very conservative in mor-phology. The test is compact with quadrangular ap-pearance and sutures make out a cross pattern in both spiral and umbilical views in four-chambered speci-mens.Distribution. According to Pearson et al. (2004) forms transitional from P. griffinoides occur as low as E7 zone in Tanzania. It persisted until the Lower Miocene (Pearson et al., 2006). Worldwide in low and mid-lat-itudes.

Occurrence. Avren Formation: C-6 Oryahovo (256.5–259 m – E11 zone), C-7 Oryahovo (230–280 m – E8–10, E11 zones), C-11 Oryahovo (435 m – E11 zone). Middle Eocene.

Genus Pаrasubbotina Olsson, Hemleben, Berggren and Liu, 1992Type species. Globigerina pseudobulloides Plummer, 1926.

Parasubbotina eoclava Coxall et al., 2003(Plate I, 4)

2003. Parasubbotina eoclava sp. n.; Coxall et al., p. 256, pl. 8, figs. 1–3 (holotype), 4–11 (paratype).

2004. Parasubbotina eoclava Coxall et al.; Pearson et al., p. 36, pl. 1, fig. 14.

2006. Parasubbotina eoclava Coxall et al.; Pearson et al., p. 89, pl. 5.9, figs. 1–16 (pl. 5.9, figs. 1–10: reillus-tration of holotype and paratypes of Parasubbotina eoclava Coxall, Huber and Pearson).

Nomenclature. The holotype (Smithsonian Museum of Natural History, Washington, No. USNM 517714) and the paratypes (USNM 517715-517716) designat-ed by Coxall et al. (2003, p. 256, pl. 8, figs. 1–3 – ho-lotype, 4–11 – paratype) were derived from ODP Hole 865B, Allison Guyot, central equatorial Pacific. Material. Relatively few perfectly preserved speci-mens.Description. Weakly cancellate, Clavigerinella-type texture, spinose in life. Test very low trochospiral, somewhat laterally compressed, lobulate-petaloid in outline. Chambers are globular and well separat-ed with a tendency for the final chamber to become slightly radially elongated. Spiral surface flattened so that chambers of inner whorl are distinguishable; su-tures straight, slightly depressed. In umbilical view 4 chambers in the final whorl, increasing rapidly in size; umbilicus small, narrow and deep; sutures straight and slightly depressed. Primary aperture a moderately high arch, interiomarginal, umbilical-extra umbilical, bordered by asymmetrical flaring lip that extends from the umbilicus to the equatorial margin.Remarks. The species is first described in Bulgaria.Discussion. Coxall et al. (2003) erected the species Parasubbotina eoclava to include some forms pre-viously referred to P. inaequispira that they consid-ered as distinct from the holotype morphology of that taxon and show some transitional features toward Clavigerinella, particularly the strongly asymmetrical aperture with its broad lip, the low trochospiral coil-ing, and the tendency for radially extended chambers.Distribution. The species occur in the end of the Lower Eocene Аcarinina cuneicamerata E7 zone (Berggren, Pearson, 2005) and persist until the Middle Eocene Globigerinatheka kugleri/Morozovella aragonensis E9 zone (Berggren, Pearson, 2005). Parasubbotina eoclava is known from the low to mid latitudes.

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Occurrence. Clay-marl formation: Р-2 Komoshtitsa (880–940 m – E6–7 zone). Lower–Middle Eocene.

Parasubbotina inaequispira (Subbotina, 1953)(Plate I, 5–6)

1953. Globigerina inaequispira sp. n.; Subbotina, p. 69, pl. 6, fig. 1a–c (holotype), 4a–c, pl. 6, figs. 2a–3c (in Russian).

1975. Globigerina inaequispira Subbotina; Stainforth et al., p. 191, fig. 54: 1a–c [from Subbotina, 1953], fig. 54: 2a–c [reillustration of holotype], fig. 54: 3–5.

1979. Subbotina inaequispira (Subbotina); Blow, p. 1272, pl. 151, figs. 5–7, pl. 163, figs. 4–8, pl. 180, figs. 1, 4–7, pl. 191, fig. 7.

1985. Globigerina inaequispira Subbotina; Toumarkine and Luterbacher, p. 117, fig. 19: 5a–c [reillustration of holotype].

1986. Subbotina inaequispira (Subbotina); Dzhuranov and Darakchieva, p. 6, pl. 1, fig. 1 (in Bulgarian).

2001. Subbotina inaequispira (Subbotina); Warraich and Ogasawara, p. 48, fig. 13: 17–19.

2004. Parasubbotina inaequispira (Subbotina); Pearson et al., p. 36, pl. 1, fig. 13.

2006. Parasubbotina inaequispira (Subbotina); Pearson et al., p. 93, pl. 5.11, figs. 1–15 (pl. 5.11, figs. 1–3: SEMs of holotype of Globigerina inaequispira Subbotina).

Nomenclature. The holotype (VNIGRI Coll., No. 3069) was designated by Subbotina (1953). It was found in the Eocene foraminiferous layers of the “green formation“ Kuban River (North Caucasus).Material. Hundreds of specimens with excellent pres-ervation.Remarks. The species was found and described as Subbotina inaequispira from the Lower Eocene (Avren and Aladan Formations) of Northeastern Bulgaria by Dzhuranov and Darakchieva (1986, p. 6, pl. 1, fig. 1). The taxonomy presented here include the spescies in genus Parassubotina based on its coiling mode and the fact that P. inaequispira has been ob-served to intergrade with other parasubbotinids. There are no variations in morphology between the material from Lom depression, the holotype and the specimens figured by Dzhuranov and Darakchieva (1986). Distribution. The species appeared in the beginning of the Eocene in Acarinina sibaiyaensis E1 zone (Berggren, Pearson, 2005) and persisted to the Middle Eocene Gümbelitrioides nuttalli E8 zone (Berggren, Pearson, 2005). Global in low to mid latitudes.Occurrence. In Lom depression the species was estab-lished at different levels of all litostratigraphic units in boreholes: С-6 Oryahovo (345–465 m – E2, E6–7, E8–10 zones); С-7 Oryahovo (360 m – E7a zone); Р-1 Dalgodeltsi (1080–1380 m – E5, E6, E7 zones), Р-1 Kovachitsa (930–1080 m – E4, E5–6 zones), Р-2 Komoshtitsa (880–1348 m – E5, E6–7 zones), Р-3 Komoshtitsa (1060–1260 m – E5, E7 zones). Lower–Middle Eocene.

Parasubbotina varianta (Subbotina, 1953)(Plate I, 7–8)

1953. Globigerina varianta sp. n.; Subbotina, p. 63, pl. 3, figs. 5a–7c, 10a–11c, 12a–c, pl. 4, figs. la–3c (in Russian).

1962. Globorotalia (Globorotalia) varianta (Subbotina); von Hillebrandt, p. 125, pl. 12, figs. 10a–11b.

1963. Globigerina pseudobulloides varianta (Subbotina); Gohrbandt, p. 45, pl. 1, figs. 10–18.

1965. Globorotalia varianta (Subbotina); Berggren, text-fig. 12.

1970a. Globigerina varianta Subbotina; Shutskaya, pp. 80–83, pl. 1, fig. 1a–c (= holotype of Subbotina, 1953, pl. 3, fig. 5a–c refigured), 6a–c, 7a–c (in Russian).

1970b. Globigerina varianta Subbotina; Shutskaya, pp. 118–120, 210, pl. 18, fig. 5a–c, p. 212, pl. 19, fig. 12a–c, p. 216, pl. 21, fig. 4a–c (in Russian).

1991a. Subbotina varianta (Subbotina); Huber, p. 441, pl. 4, figs. 6, 7.

1992. Subbotina varianta (Subbotina); Berggren, p. 563, pl. 1, fig. 3.

1994. Subbotina varianta (Subbotina); Juranov, p. 15, pl. 2, figs. 7, 8 (in Bulgarian).

1997. Parasubbotina varianta (Subbotina); Berggren and Norris, p. 81, pl. 5, figs. 17–22, pl. 6, figs. 1–3, 5.

2006. Parasubbotina varianta (Subbotina); Pearson et al., p. 97, pl. 5.13, figs. 1–16 (pl. 5.13, figs. 1–3: SEMs of holotype of Globigerina varianta Subbotina).

Nomenclature. The holotype (VNIGRI Coll. 378/20, Saint Petersburg, No. 3994) was derived from the zone of rotaliform Globorotalia, Elburgan Formation, Kuban River section, Northern Caucasus.Material. Dozens of very well preserved specimens.Remarks. The species was first described from the Paleocene of Eastern Stara Planina in the Emine Formation (Juranov, 1994). It is also known from the Byala Formation (Juranov, 1983) and from the Paleocene near the village of Kladorub (Valchev, Juranov, 2006).Discussion. Subbotina’s holotype is a poorly preserved specimen but nevertheless shows the cancellate wall and inflated, closely appressed chambers that char-acterize the Parasubbotina clade. It is very difficult to place clear morphological bounds on the taxon as specimens differ widely in chamber arrangement and apertural characteristics. This was noted by Subbotina (1953) in her original description and probably ac-counts for the species name. Parasubbotina varianta is distinguished from P. inaeguispira by its more closely appressed chambers.Distribution. Parasubbotina varianta is known from Globanomalina compressa/Praemurica inconstans Р1с zone (Berggren, Pearson, 2005) to Acarinina topilen-sis Е10 zone (Berggren, Pearson, 2005). Worldwide in high and low latitudes. Occurrence. In Lom depression the species was es-tablished in the limestone-marl formation, clay-marl formation, Komarevo Formation and marl-limestone formation: Р-1 Asparuhovo (1218–1414 m – P1c–P3a,

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P4 zones), Р-3 Asparuhovo (1317–1509 m – P1c–P3a, P3b, P4 zones), Р-5 Asparuhovo (1176–1307 m – P1c–P3a zone), Р-1 Kovachitsa (1000–1080 m – P5, E4 zones), Р-2 Komoshtitsа (970–1348 m – E5, E6–7 zones), Р-3 Komoshtitsa (1260–1400 m – P4, E5 zones), С-6 Oryahovo (365–465 m – E2, E6–7, E8–10 zones), Р-1 Dalgodeltsi (1260–1340 m – E5, E6 zones).

Genus Globigerina dʼOrbigny, 1826Type species. Globigerina bulloides d’Оrbigny, 1826.

Globigerina officinalis Subbotina, 1953(Plate I, 9–10)

1953. Globigerina officinalis sp. n.; Subbotina, p. 78, pl. 11, fig. 1a–c (holotype), figs. 2–7 (paratypes) (in Russian).

1962. Globigerina officinalis Subbotina; Blow and Banner, p. 88, pl. 9, figs. A–C.

1962. Globigerina praebulloides leroyi subsp. n.; Blow and Banner, p. 93, pl. 9, figs. R–T.

1969. Globigerina officinalis Subbotina; Blow, p. 78, pl. 1, figs. 1–7 (reillustration of Blow and Banner, 1962, pl. 9, figs. A–C).

1976. Globigerina officinalis Subbotina; Quilty, p. 671, pl. 3, figs. 8–9.

1979. Globigerina officinalis Subbotina; Blow, p. 798, pl. 1, figs. 1–7 (reillustration of Blow and Banner, 1962, pl. 9, figs. A–C).

1990. Globigerina officinalis Subbotina; Spezzaferri and Silva, p. 244, pl. VI, figs. 1a–b, 2a–c.

1991. Globigerina officinalis Subbotina; Van Eijden and Smit, p. 110.

1995. Globigerina officinalis Subbotina; Poag and Com-meau, pl. 7, figs. 8, 9.

1999. Globigerina officinalis Subbotina; Darakchieva, p. 52.2006. Globigerina officinalis Subbotina; Pearson et al., p.

119, pl. 6.1, figs. 1–16 (pl. 6.1, figs. 1–3: new SEMs of paratype of Globigerina oficinalis Subbotina).

2015. Globigerina officinalis Subbotina; Pearson and Wade, p. 9, fig. 5.1–5.2.

Nomenclature. The holotype (VNIGRI Coll., Saint Petersburg, No. 4038) was designated by Subbotina (1953) from the Upper Eocene, Bolivina Zone, Khieu River, surroundings of Nalchik, Northern Caucasus. Material. Dozens of excellent preserved specimens.Description. Normal perforate, spinose, bulloides-type wall structure. Test low trochospiral, lobulate in outline, chambers globular; in spiral view 4 globular, slightly embracing chambers in ultimate whorl, increasing rap-idly in size, sutures moderately depressed, straight; in umbilical view 3½ globular, slightly embracing cham-bers, increasing rapidly in size, sutures moderately depressed, straight, umbilicus small, open, enclosed by surrounding chambers, aperture umbilical, a low to high arch bordered by an imperforate rim; in edge view chambers globular in shape, slightly embracing. Remarks. In Bulgaria the species is known from the Eocene of Lom depression (Tzaneva, 1964) and it was

also established and figured from the Upper Eocene in Krumovgrad District (Darakchieva, 1999). Here it is first described taxonomically. Discussion. Globigerina officinalis appears to be the initial species in the evolution of the genus Globi­gerina. Subbotina (1953) noted the variability in size of the ultimate chamber of G. officinalis and illustrat-ed this range of variation in a suite of specimens (ho-lotype and originals). G. praebulloides leroyi closely resembles Subbotina’s figure 2a–c, and is treated as a morphotype of Globigerina officinalis. It is distin-guished from Globigerina praebulloides by its less gaping aperture and slower rate of chamber enlarge-ment (Pearson et al., 2006).Distribution. The species is characterized by a broad stratigraphic range, appearing in the Middle Eocene zone Acarinina topilensis E10 (Berggren, Pearson, 2005) and disappears in the Oligocene. Distributed in low to mid latitudes.Occurrence. Avren Formation: C-6 Oryahovo (250–347 m – E8–10, E11 zones).

Genus Subbotina Brotzen and Pozaryska, 1961Type species. Globigerina triloculinoides Plummer, 1926.

Subbotina angiporoides (Hornibrook, 1965)(Plate I, 11–12)

1939. Globigerina angipora Stache; Finlay, p. 125. 1965. Globigerina angiporoides sp. n.; Hornibrook, pp. 835–

838, fig. 1a (holotype), b–e (paratypes), f–i, fig. 2.1966. Globigerina angiporoides minima subsp. n.; Jenkins,

p. 1096, fig. 7, nos. 52–57.1971. Globigerina (Subbotina) angiporoides angiporoides

Hornibrook; Jenkins, p. 160, pl. 20, figs. 588–594.1983. Globigerina (Subbotina) angiporoides angiporoides

Hornibrook; Krasheninnikov and Basov, p. 838, pl. 3, figs. 1–4.

1988. Subbotina angiporoides (Hornibrook); Poore and Bybell, pl. 4, figs. 10, 11.

1990. Subbotina angiporoides (Hornibrook); Stott and Kennett, p. 559, pl. 7, fig. 3.

1991a. Subbotina angiporoides (Hornibrook); Huber, p. 440, pl. 5, figs. 5, 9.

2006. Subbotina angiporoides (Hornibrook); Pearson et al., p. 128, pl. 6.6, figs. 1–13 (pl. 6.6, figs. 1–3: SEMs of holotype of Globigerina angiporoides Hornibrook, pl. 6.6, figs. 9–11: SEMs of holotype of Globigerina angiporoides minima Jenkins).

Nomenclature. Holotype (New Zealand Geological Survey Coll., No. TF 1491/1) is the specimen desig-nated by Hornibrook (1965). It originates from the Macdonald Limestone, at Kakanui, on the east coast of South Island, New Zealand.Material. Dozen of species with bad or good preserva-tion.Description. Spinose, normal perforate, moderately cancellate, often thickened by addition of gametoge-netic calcite, sacculifer/ruber-type wall. Test small to

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moderate in size, axial periphery rounded, consisting of three tightly coiled, strongly embracing whorls with usually 4 chambers in the final whorl. The chambers are strongly embracing, inflated, increasing mod-erately in size, tend to be elongated along the radial axis. The final chamber is variable, usually strongly embracing, and extended over the umbilical sutures; sutures weakly depressed, radial to slightly curved. The aperture is a low, indistinct, interiomarginal slit bordered by a thick lip that extends the full width of the chamber face, opening in and sometimes beyond the umbilical area.Remarks. The species is first described in Bulgaria.Discussion. Hornibrook (1965) declared that Globi­gerina angipora Stache is a nomen dubium. None of Stache’s specimens deposited in Geological Paleontological Section of the Natural History Museum in Vienna has been found. The original figures and descriptions are not adequate to identify the species. The name Globigerina angiporoides was proposed for the species previously called Globigerina angipora Stache in the Upper Eocene and Lower Oligocene in New Zealand to maintain continuity with previous re-cords in publications and reports under the name an-gipora. Jenkins (1966) distinguished Globigerina an­giporoides minima as an ancestral form that is smaller and less tightly coiled with a more open umbilicus and more inflated chambers. However, Pearson et al. (2006) regard these foms very difficult to distinguish consistently andconsidered them synonymous. Distribution. It is difficult to determine the first ap-pearance of Subbotina angiporoides because of the morphological similarities of the earliest forms with Subbotina linaperta. Pearson et al. (2006) de-fine the stratigraphic range of the species between Morozovelloides lehneri E11 zone (Berggren, Pearson, 2005) and G. angulisuturalis/C. cubensis O4 zone (Berggren, Pearson, 2005). Cosmopolitan; most common at high latitudes especially in its upper range when it nearly disappears from low latitudes.Occurrence. Avren Formation: C-6 Oryahovo (253–326 m – E11 zone), C-7 Oryahovo (240–250 m – E11 zone).

Subbotina corpulenta (Subbotina, 1953)(Plate I, 13)

1953. Globigerina corpulenta sp. n.; Subbotina, p. 76, pl. 9, figs. 5a–7c (5a–c = holotype), pl. 10, figs. 1a–4b.

1953. Globigerina pseudoeocaena var. pseudoeocaena subsp. n.; Subbotina, p. 81, pl. 5, fig. 6a–c (partim, not holotype).

1953. Globigerina inflata dʼOrbigny; Subbotina, p. 94, pl. 7, figs. 6a–8b (partim, not pl. 8, fig. 7a–c), pl. 8, fig. 1a–c, pl. 8, figs. 2a–6c, pl. 15, figs. 4a–6c [not dʼOrbigny, 1839].

1957. Globigerina pera sp. n.; Todd, p. 301, pl. 70, figs. 10, 11.

1962. Globigerinita pera Todd; Blow and Banner, p. 112, pl. 14, figs. E–H.

1975. Globigerina cryptomphala Glaessner; Toumarkine, p. 742, pl. 1, fig. 5.

1977. Globigerina eocaena Gümbel; Poore and Brabb, p. 255, pl. 4, fig. 12 [not Gümbel, 1868].

1980. Catapsydrax pera (Todd); Charollais et al., pl. 5, fig. 14.

1985. Globigerina cryptomphala Glaessner; Toumarkine and Luterbacher, p. 149, fig. 42: 5a, b [reillustra-tion of holotype, Upper Eocene, North Caucasus], fig. 42: 6 [reillustration of Charollais et al., 1980, pl. 5, fig. 14, Lower Oligocene, France, identified as Catapsydrax pera (Todd)].

1999. Globigerina corpulenta Subbotina; Darakchieva, p. 51.2006. Subbotina corpulenta (Subbotina); Pearson et al.,

p. 131, pl. 6.7, figs. 1–14 (pl. 6.7, figs. 1–3: SEMs of holotype of Globigerina corpulenta Subbotina).

2015. Subbotina corpulenta (Subbotina); Pearson and Wade, p. 13, fig. 10: 3–4c.

Nomenclature. The holotype (VNIGRI collec-tion, Saint Petersburg, No. 4033) was designated by Sub botina (1953) from the Upper Eocene zone of Globigerinoides conglobatus and large Globigerina, Khieu River, surroundings of Nalchik, Northern Caucasus. Material. Hundreds of specimens with excellent pres-ervation.Description. Cancellate, normal perforate, spinose type of wall. Test large in size, moderately high trocho-spiral, lobulate in outline, consisting of three whorls, 4–4½ globular chambers in ultimate whorl, increas-ing moderately in size, sutures moderately depressed, straight to slightly curved. Umbilicus moderate in size, very often the ultimate chamber is cantilevered over it resembling a bulla. Aperture umbilical, gener-ally without a lip. In edge view test with a moderately elevated initial whorl, chambers globular in shape, ap-erture generally not visible.Remarks. The species is known from the Eocene of Lom depression (Tzaneva, 1964) and from the Upper Eocene in South Bulgaria, Mugris Formation (Darakchieva, 1999). Here the species is first de-scribed taxonomically.Discussion. Subbotina corpulenta belongs to the group of large subbotinids which includes S. eocaena and S. hagni. It differs from S. hagni in the arrange-ment of the ultimate chamber, which is cantilevered over the umbilicus in varying degrees. Subbotina eo­caena is more tightly coiled and has 3½ chambers in the ultimate whorl.Distribution. Subbotina corpulenta appeared in the Lower Eocene Аcarinina cuneicamerata Е7 zone (Berggren, Pearson, 2005) and persisted to the begin-ning of the Oligocene. Global in low to mid latitudes.Occurrence. In Lom depression the species was es-tablished in the sediments of Avren Formation, marl-limestone formation and clay-marl formation in boreholes С-6 Oryahovo (267–375 m – E8–10, E11 zones), C-7 Oryahovo (230–250 m – E11 zone), С-8 Oryahovo (420–430 m – E7–11 zone), С-11 Oryahovo

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(408–465 m – E7b zone), Р-1 Dalgodeltsi (1100– 1220 m – E7 zone), Р-2 Komoshtitsa (940–1160 m – E6–7 zone), Р-3 Komoshtitsa (780–820 m – E7 zone).

Subbotina crociapertura Blow, 1979(Plate II, 1–3)

1979. Subbotina crociapertura sp. n.; Blow, p. 1257, pl. 176, figs. 1–9, pl. 177, figs. 1, 2, pl. 190, figs. 6–9, pl. 191, figs. 1–5 (figs. 2 and 3 = holotype).

2004. Subbotina crociapertura Blow; Pearson et al., p. 36, pl. 1, fig. 12.

2006. Subbotina crociapertura Blow; Pearson et al., p. 132, pl. 6.8, figs. 1–14 (pl. 6.8, figs. 1, 2: reil-lustration of holotype of Subbotina crociapertura Blow, pl. 6.8, figs. 3–8: reillustration of paratypes of Subbotina crociapertura Blow).

Nomenclature. Holotype (Natural History Museum, London) is the specimen designated by Blow (1979). It originates from the Middle Eocene of Tanzania, Kilwa area. Material. Dozens of specimens with escellent preser-vation.

Description. Cancellate, normal perforate, spinose, bulloides-type wall structure. Low trochospiral, gobu-lar test, oval in outline, with 4 globular, slightly em-bracing chambers in ultimate whorl, increasing rapidly in size, sutures moderately depressed, straight, umbi-licus small, open, enclosed by surrounding chambers, aperture umbilical to extraumbilical, elevated above the umbilicus, bordered by a prominent lip that tapers towards the posterior side of the ultimate chamber; in edge view chambers globular in shape, slightly em-bracing, aperture visible as a moderately high, circular arch, bordered by a regular lip. Remarks. This species is characterized by its globular, slightly embracing, chambers with a characteristically crooked, high-arched aperture bordered by a promi-nent regular lip. Here it is first described in Bulgaria.Distribution. The species appeared in the Lower Eocene Аcarinina cuneicamerata E7 zone (Berggren, Pearson, 2005) and persisted to the Middle Eocene Orbulinoides beckmanni E12 zone (Berggren, Pearson, 2005). Widely distributed in low latitudes.Occurrence. Avren Formation: С-6 Oryahovo (316–347 m – E8–10, E11 zones), C-7 Oryahovo (230 m – E11 zone).

PLATE II

1–3. Subbotina crociapertura Blow, 1979. С-6 Oryahovo, 326 m, sample 26, Avren Formation, Middle Eocene, E11 zone; 1, edge view SEM x 220; 2, spiral view, SEM x 200; 3, umbilical view, SEM x 220.4, 5. Subbotina eocaena (Gümbel, 1868). С-6 Oryahovo, 347 m, sample 28, Avren Formation, Middle Eocene, E8–10 zone; 4, spiral view, SEM x 200; 5, umbilical view, SEM x 190.6, 7. Subbotina hagni (Gohrbandt, 1967). С-6 Oryahovo, 347 m, sample 28, Avren Formation, Middle Eocene, E8–10 zone; 6, umbilical view, SEM x 170; 7, spiral view, SEM x 170.8, 9. Subbotina linaperta (Finlay, 1939). С-6 Oryahovo, 347 m, sample 28, Avren Formation, Middle Eocene, E8–10 zone; 8, umbilical view, SEM x 230; 9, spiral view, SEM x 300.10, 11. Subbotina roesnaesensis Olsson & Berggren, 2006. 10, С-6 Oryahovo, 347 m, sample 28, Avren Formation, Middle Eocene, E8–10 zone; spiral view, SEM x 220; 11, R-2 Komoshtitsa, 1020 m, sample 100, clay-marl formation, Middle Eocene, E6–7 zone; umbilical view, SEM x 220.12, 13. Subbotina senni (Beckmann, 1953). С-7 Oryahovo, 300 m, sample 25, Avren Formation, Middle–Upper Eocene, E7b sub-zone; 12, edge view, SEM x 200; 13, umbilical view, SEM x 200.

ТАБЛИцА II

1, 2, 3. Subbotina crociapertura Blow, 1979. С-6 Оряхово, 326 m, проба 26, Авренска свита, Среден Еоцен, зона E11; 1 – странична, SEM x 220; 2 – спирална страна, SEM x 200; 3 – пъпна страна, SEM x 220.4, 5. Subbotina eocaena (Gümbel, 1868). С-6 Оряхово, 347 m, проба 28, Авренска свита, Среден Еоцен, зона E8–10; 4 – спи-рална страна, SEM x 200; 5 – пъпна страна, SEM x 190.6, 7. Subbotina hagni (Gohrbandt, 1967). С-6 Оряхово, 347 m, проба 28, Авренска свита, Среден Еоцен, зона E8–10; 6 – пъпна страна, SEM x 170; 7 – спирална страна, SEM x 170.8, 9. Subbotina linaperta (Finlay, 1939). С-6 Оряхово, 347 m, проба 28, Авренска свита, Среден Еоцен, зона E8–10; 8 – пъпна страна, SEM x 230; 9 – спирална страна, SEM x 300.10, 11. Subbotina roesnaesensis Olsson & Berggren, 2006. 10 – С-6 Оряхово, 347 m, проба 28, мергелно-варовикова задруга, Среден Еоцен; спирална страна, SEM x 220; 11 – Р-2 Комощица 1020 m, проба 100, глинесто-мергелна задруга, Среден Еоцен, зона Е6–7; пъпна страна, SEM x 220.12, 13. Subbotina senni (Beckmann, 1953). С-7 Оряхово, 300 m, проба 25, Авренска свита Среден–Горен Еоцен, подзона E7b; 12 – страничен изглед, SEM x 200; 13 – пъпна страна, SEM x 200.

Scale bar – 100 μm

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PLATE II ТАБЛИЦА II

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Subbotina eocaena (Gümbel, 1868)(Plate II, 4–5)

1868. Globigerina eocaena sp. n.; Gümbel, p. 662, pl. 2, fig. 109a, b.

1882. Globigerina eocaenica sp. n.; Terquem, p. 86, pl. 9, fig. 4.

1953. Globigerina eocaenica var. irregularis subsp. n.; Subbotina, p. 81, pl. 11, figs. 12a–14c.

1953. Globigerina pseudoeocaena var. compacta subsp. n.; Subbotina, p. 68, pl. 5, fig. 3a–c [holotype], pl. 5, fig. 4a–c.

1953. Globigerina pseudoeocaena var. trilobata subsp. n.; Subbotina, p. 68, pl. 5, fig. 5a–c.

1953. Globigerina eocaena Gümbel; Subbotina, p. 70, pl. 6, fig. 5a–c, pl. 7, fig. 1a–c [= Subbotina hagni (Gohrbandt, 1967)].

1959. Globigerina pseudoeocaena Subbotina; Stancheva, p. 335, pl. 3, fig. 1а–b (in Bulgarian).

1969. Globigerina (Subbotina) eocaena Gümbel; Hagn and Lindenberg, p. 336, pl. 1, fig. 1a–c [neotype, Upper Eocene, Gerhartsreiter Graben, Siegsdorf, Bavarian Alps, Austria], pl. 1, fig. 5a–c [partim; not pl. 1, figs. 2a–4 = Subbotina corpulenta (Subbotina)].

1979. Subbotina eocaenica (Terquem); Blow, p. 1260, pl. 151, fig. 10, pl. 160, fig. 1 (partim; not pl. 142, figs. 4, 5, pl. 153, fig. 9).

1985. Globigerina eocaena Gümbel; Toumarkine and Luterbacher, p. 149, fig. 42: 1a–c (reillustration of neotype, Hagn and Lindenberg, 1969, p. 336, pl. 1, fig. La, c), fig. 42.2, 4, fig. 42.3.

1995. Globigerina eocaena Gümbel; Poag and Commeau, p. 149, pl. 6, fig. 19 (partim, not pl. 8, figs. 3, 4).

2006. Subbotina eocaena (Gümbel); Pearson et al., p. 135, pl. 6.9, figs. 1–16 (pl. 6.9, figs. 11–13: SEMs of holotype of Globigerina pseudoeocaena var. com­pacta Subbotina, pl. 6.9, figs. 14–16: SEMs of ho-lotype of Globigerina pseudoeocaena var. trilobata Subbotina).

2015. Subbotina eocaena (Gümbel); Pearson and Wade, p. 13, figs. 10.5a–8b.

Nomenclature. The neotype, selected by Hagn and Lindenberg (1969), is deposited in the Bavarian State Collection for Paleontology and Historical Geology in Munich, Germany.Material: Hundreds of specimens with excellent pres-ervation. Remarks. The species was first described from the Eocene near the villages Tarnene and Opanets (Stancheva, 1959). The author recognized in the sam-ples the varietes G. pseudoeocaena var. pseudoeocae­na and G. pseudoeocaena var. compacta differentiat-ing them according to the compression of the trocho-spiral test. It is also known from the Eocene in Lom depression (Tsaneva, 1963, 1964).Discussion. Gümbel (1868) did not designated a ho-lotype specimen when he described the species. Hagn and Lindenberg could not locate his original material in the Bavarian State collections for Paleontology and Historical Geology in Munich, therefore they selected a neotype from a sample taken from strata that Gümbel

had studied in 1868 from the Gerhartsreiter Graben near Siegsdorf, Austria. A species that appears mor-phologically similar to G. eocaena is Globigerina eo­caenica Terquem, 1882. The type specimen of G. eo­caenica, according to Berggren (1960) is broken and unusable and he recommended that Terquem’s taxon should be considered as nomen dubium non conse-wandum. Since Terquem described G. eocaenica from the Middle Eocene where G. eocaena is common, it is probable that G. eocaenica is a junior synonym of G. eocaena. Subbotina (1953) described the varieties of G. pseudoeocaena: G. pseudoeocaena var. compacta and G. pseudoeocaena var. trilobata which fall within the morphologic range of Subbotina eocaena. Distribution. Subbotina eocaena appeared in the end of the Lower Eocene Аcarinina pentacamerata Е5 zone (Berggren, Pearson, 2005) and persisted to the Oligocene. Global in low to mid latitudes.Occurrence. In Lom depression the species was estab-lished in the sediments of marl-limestone formation, Avren Formation, limestone-marl formation and clay-marl formation in boreholes С-10 Leskovets (274– 363 m – E6, E7–9 zones), Р-1 Kovachitsа (930–980 m – E5–6 zone), Р-2 Komoshtitsa (880–1160 m – E6–7 zone), Р-3 Komoshtitsa (780–1180 m – E7 zone), Р-1 Dalgodeltsi (1080–1420 m – E5, E6, E7 zones), С-6 Oryahovo (253–435 m – E6–7, E8–10, E11 zones), C-7 Oryahovo (230–350 m – E7a, E7b, E8–10, E11 zones), С-8 Oryahovo (430–490 m – E7–11 zone), С-11 Oryahovo (425–495 m – E5–7a, E7b, E8, E 9–10, E11 zones).

Subbotina hagni (Gohrbandt, 1967)(Plate II, 6–7)

1953. Globigerina eocaena Gümbel; Subbotina, p. 85, pl. 6, fig. 5a–c, pl. 7, fig. 1a–c [not Gümbel, 1868].

1967. Globigerina hagni sp. n.; Gohrbrandt, p. 324, pl. 1, figs. 1–9 (1–3 = holotype, 4–9 = paratypes).

1977. Subbotina hagni (Gohrbandt); Poore and Brabb, p. 269, pl. 4, figs. 13, 14.

1985. Globigerina hagni Gohrbandt; Toumarkine and Luterbacher, p. 150, fig. 42: 7a–c (reilustration of holotype); figs. 8, 9.

2001. Subbotina hagni (Gohrbandt); Warraich and Ogasawara, p. 48, fig. 14: 5–7.

2006. Subbotina hagni (Gohrbandt); Pearson et al., p. 139, pl. 6.11, figs. 1–17 (pl. 6.11, figs. 1–3: SEMs of topotype of Globigerina hagni Gohrbandt).

Nomenclature. Holotype (Naturhistorisches Museum, Vienna, Austria, No. 683/10/1966) is the specimen, designated by Gohrbandt (1967, p. 324, pl. 1, figs. 1–3), originating from the outskirts of the town of Matze (Austria).Material. Hundreds of specimens with excellent pres-ervation.Description. Cancellate, normal perforate, spinose, ruber/sacculifer-type wall texture. Test low trocho-spiral, quadrate in outline, equatorial periphery lobate,

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axial periphery rounded. Chambers globular, some-what ovate, 10–12, arranged in about two and one-half whorls, the last whorl with 4–4½ chambers increas-ing moderately in size, the final chamber in fully adult specimens equal in size to or smaller than the penulti-mate chamber. Sutures straight, moderately depressed, umbilicus small, enclosed by surrounding chambers. Aperture a distinct slit at the base of the last chamber, extraumbilical-umbilical, bordered in well-preserved specimens with a thin, irregular apertural lip.Remarks. The species is first described in Bulgaria.Discussion. This relatively large species of Globigerina is well-represented, with significant frequency in a large number of samples. It is a very distinct form with its four some-what compressed, globular chambers and the extraumbilical-umbilical aperture. Gohrbandt (1967) noted that the species was previously reported under the name Globigerina eocaena (Gümbel) by Subbotina (1953), from Southern Russia, although he did not formally place it in synonomy with his new species.Distribution. Subbotina eocaena appeared in the end of the Lower Eocene Аcarinina cuneicamerata Е7 zone (Berggren, Pearson, 2005) and persisted to the end of the Upper Eocene Hantkenina alabamensis E16 zone (Berggren, Pearson, 2005). Apparently global in low to mid latitudes.Occurrence. In Lom depression the species was es-tablished in the sediments of marl-limestone forma-tion, Avren Formation and clay-marl formation in boreholes С-10 Leskovets (274 m – E7–9 zone), С-6 Oryahovo (267–365 m – E8–10 zone), C-7 Oryahovo (300 m – E7b zone), С-8 Oryahovo (420–430 m – E7–11 zones), С-11 Oryahovo (425–445 m – E8, E9–10, E11 zones), Р-1 Dalgodeltsi (1080–1130 m – E7 zone), Р-2 Komoshtitsa (940 m – E6–7 zone), Р-3 Komoshtitsa (820–1120 m – E7 zone).

Subbotina linaperta (Finlay, 1939)(Plate II, 8–9)

1939. Globigerina linaperta sp. n.; Finlay, p. 125, pl. 23, figs. 54–57.

1958. Globigerina linaperta Finlay; Hornibrook, p. 33, pl. 1, figs. 19–21 (reillustration of holotype).

1971. Globigerina (Subbotina) linaperta Finlay; Jenkins, p. 162, pl. 18, figs. 551–554 (551–553: reillustra-tions of holotype, 554 topotype).

p1975. Globigerina linaperta Finlay; Stainforth et al., p. 201, fig. 63: 1a–c (partim; not fig. 63: 2–5), (reillustration of holotype).

1975. Globigerina linaperta Finlay; Toumarkine, p. 742, pl. 1, figs. 1, 2.

1977. Subbotina linaperta (Finlay); Poore and Brabb, p. 269, pl. 5, fig. 8, pl. 5, fig. 9.

p1979. Subbotina linaperta (Finlay); Blow, p. 1275, pl. 124, fig. 9 [not pl. 91, fig. 8, pl. 158, fig. 8, pl. 160, figs. 6–8, pl. 177, figs. 4–6, pl. 240, figs. 5, 6].

1983. Globigerina linaperta Finlay; Krasheninnikov and Basov, p. 838, pl. 2, figs. 8–11.

1986. Subbotina linaperta (Finlay); Dzhuranov and Da-rakchieva, p. 7, pl. 1, figs. 2–3 (in Bulgarian).

1990. Subbotina linaperta (Finlay); Stott and Kennett, p. 559, pl. 7, fig. 9.

1991a. Subbotina linaperta (Finlay); Huber, p. 440, pl. 5, fig. 1.

1992. Subbotina linaperta (Finlay); Berggren, p. 583, pl. 3, figs. 1–4.

2004. Subbotina linaperta (Finlay); Wade, p. 28, pl. 1, figs. d–f.

2006. Subbotina linaperta (Finlay); Pearson et al., p. 144, pl. 6.14, figs. 1–16 (pl. 6.14, figs. 1–3: SEMs of paratype of Globigerina linaperta Finlay).

Nomenclature. Holotype (Geological and Nuclear Science Institute, Lower Hutt, New Zealand, No. TF 1078/1) is the specimen designated by Finlay (1939) from the Middle Eocene, Bortonian Stage, Hampden section, South Island, New Zealand. Material. Hundreds of specimens with excellent pres-ervation. Remarks. The species was found and described from the Upper Paleocene–Lower Eocene (Avren and Aladan Formations) of Northeastern Bulgaria by Dzhuranov and Darakchieva (1986, p. 7, pl. 1, figs. 2–3).Discussion. Subbotina linaperta show varying degrees of equatorial flattening of the final whorl chambers and variable rates of increasing chamber size. Subbotina linaperta belongs to a group of tightly coiled subboti-nids with a coarse, symmetrical cancellate wall tex-ture. Pearson et al. (2006) stated that S. linaperta is derived from S. patagonica by flattening of chambers and rotation of the aperture to a more extraumbilical position. Distribution. Subbotina linaperta appeared in Mоro-zovella aragonensis/Morozovella subbotinae Е5 zone and persisted to Hantkenina alabamensis Е16 zone (Berggren, Pearson, 2005). Cosmopolitan. Particularly common during the Middle Eocene at southern, high latitudes.Occurrence. In Lom depression the species was es-tablished in the sediments of marl-limestone forma-tion, Avren Formation, clay-marl formation and lime-stone-marl formation in boreholes С-10 Leskovets (274–343 m – E7–9 zone), Р-1 Kovachitsa (930– 960 m – E5–6 zone), Р-2 Komoshtitsa (880–1348 m – E5, E6–7 zones), Р-3 Komoshtitsa (780–1300 m – E5, E7 zones), Р-1 Dalgodeltsi (1080–1410 m – E2, E5, E6, E7 zones), С-6 Oryahovo (253–435 m – E6–7, E8–10, E11 zones), С-7 Oryahovo (230–380 m – E5–6, E7a, E7b, E8–10, E11 zones), С-8 Oryahovo (420–500 m – E5–7, E8–11 zones), С-11 Oryahovo (408–505 m – E5–7a, E7b, E8, E9–10, E11 zones).

Subbotina roesnaesensis Olsson and Berggren, 2006(Plate II, 10–11)

1953. Globigerina eocaenica var. eocaenica Terquem; Subbotina, pp. 80–81, pl. 11, fig. 8a–c, fig. 9a–c

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(partim; not pl. 11, figs. 10a–11c) [not Terquem, 1882].

1960. Globigerina yeguaensis Weinzierl and Applin; Berg-gren, p. 73–83, pl. 2, figs. 1a–4c, pl. 3, figs. 1a–3c, pl. 4, figs. 1a–2c, pl. 8, figs. 1a–5c, text-fig. 1, pl. 2, fig. 1a–c, pl. 3, fig. 2a–c, pl. 8, fig. 1a–c, pl. 4, figs. 1a–2c, pl. 2, figs. 3a–4c, pl. 8, fig. 4, pl. 4, figs. 1a–2c (partim, not pl. 2, figs. 2a–4c, pl. 3, figs. la–c, 3a–c, pl. 8, figs. 2a–5c) [not Weinzierl and Applin, 1929].

1979. Subbotina eocaenica (Terquem); Blow, pp. 1260–1262, pl. 142, figs. 4, 5, pl. 152, fig. 9, pl. 160, fig. 1 [not Terquem, 1882].

1991a. Subbotina velascoensis (Cushman); Huber, p. 441, pl. 4, figs. 11, 12 [not Cushman, 1925].

1992. Subbotina patagonica (Todd & Kniker); Berggren, p. 563, pl. 2, fig. 16.

1995. Subbotina patagonica (Todd & Kniker); Lu and Keller, p. 102, pl. 5, figs. 12–14.

2001. Subbotina patagonica (Todd & Kniker); Warraich and Ogasawara, p. 48, fig. 13: 4, 8, 12 (reillustration of Warraich et al., 2000, fig. 18: 4, 5, 11) [not Todd and Kniker, 1952].

2006. Subbotina n sp. roesnaesensis Olsson and Berggren; Pearson et al., p. 148, pl. 6.16, figs. 1–15.

Nomenclature. The holotype (Smithsonian Museum of Natural History, Washington, D. C., No. USNM 521871) was found in the Rosnaes Clay Formation in Denmark, from where the species name originates.Material. Dozens of specimens with relatively good preservation.Description. Normal perforate, spinose, ruber-type wall texture. Test relatively large, very low tro-chospiral, globular, lobulate in outline. Chambers globular, ovoid in shape, wider than high, loosely embracing, 3–4 chambers in ultimate whorl, increas-ing rapidly in size, sutures strongly depressed, gently curved on umbilical and spiral sides of the test, ulti-mate chamber varies in size from reduced to large. Umbilicus a fairly large opening, aperture umbilical, a low arch, bordered by a narrow lip that may vary slightly in width.Remarks. The species is first described in Bulgaria.Discussion. Berggren (1960, text-fig. 8) illustrated a group of “globigerinid“ morphotypes in the Lower Eocene Rosnaes Clay Formation of Denmark which exhibited a large degree of variation in the arrange-ment of chambers in the final whorl and the position of the aperture. Similar variation was observed in “glo-bigerinids“/subbotinids from equivalent stratigraphic levels in California and in the Caucasus, and this vari-ation was ascribed to intraspecific variation within a single taxon. This taxon has probably been described and/or recorded under a variety of names and guises in the literature, particularly in the former Soviet Union. Pearson et al. (2006) designated a new name – roesna­esensis (which has an asymmetric ruber-wall texture) for them. Distribution. Subbotina roesnaesensis appeared in the Upper Paleocene Мorozovella velascoensis P5 zone (Berggren, Pearson, 2005) and persisted to the Middle

Eocene Acarinina topilensis Е10 zone (Berggren, Pearson, 2005). Global in low to mid latitudes. Occurrence. In Lom depression the species was estab-lished in the sediments of all lithosratigraphic units: Р-2 Komoshtitsa (900–1348 m – E5, E6–7 zones), Р-3 Komoshtitsa (1220 m – E5 zone), С-6 Oryahovo (328–465 m – E2, E6–7, E8–10 zones), С-7 Oryahovo (360 m – E7a zone).

Subbotina senni (Beckmann, 1953)(Plate II, 12–13)

1953. Sphaeroidinella senni sp. n.; Beckmann, p. 394, pl. 26, figs. 2–4, text-fig. 20.

1957a. Globigerina senni (Beckmann); Bolli, p. 163, pl. 35, figs. 10a–12.

1958. Globigerinoides subconglobatus var. micra subsp. n.; Shutskaya, pp. 87–88, pl. 1, figs. 1 (holotype), 2, 3.

1974. Globigerinatheka senni (Beckmann); Fleisher, p. 1021, pl. 8, figs. 10, 11.

1974. Subbotina kiersteadae sp. n.; Fleisher, p. 1032, pl. 16, figs. 1–9.

1975. Globigerina senni (Beckmann); Toumarkine, p. 750, pl. 5, figs. 5–11.

1977. “Subbotina“ senni (Beckmann); Poore and Brabb, p. 269, pl. 3, figs. 12–14.

1978. Globigerina senni (Beckmann); Toumarkine, p. 718, pl. 10, figs. 10–14.

1979. Muricoglobigerina senni (Beckmann); Blow, p. 1131, pl. 165, fig. 8 (partim; not pl. 131, figs. 7–9, pl. 142, figs. 7, 9, pl. 146, figs. 9, 10, pl. 236, figs. 1–4.).

1985. Globigerina senni (Beckmann); Toumarkine and Luterbacher, p. 127, fig. 28: 1–5 (fig. 28: la–c, reil-lustration of holotype, pl. 26, fig. 2a–c), fig. 28: 2, 3, fig. 28: 4, 5 (reillustration of Toumarkine, 1975, pl. 5, figs. 9, 10).

1986. Globigerina senni (Beckmann); Dzhuranov and Da-rakchieva, p. 8, pl. 2, fig. 2 (in Bulgarian).

2001. Muricoglobigerina senni (Beckmann); Warraich and Ogasawara, p. 42, fig. 11: 6–8.

2006. Subbotina senni (Beckmann); Pearson et al., p. 151, pl. 17, figs. 1–20 (pl. 6.17, figs. 1–3: new SEMs of holotype of Sphaeroidinella senni Beckmann, pl. 6.17, figs. 5–7: SEMs of holotype of Globigerina orbiformis Cole).

Nomenclature. The holotype was designated by Beckman (1953) and it is deposited in the Museum of Natural History, Basel, Switzerland. It was found in Middle Eocene, Mount Hillaby, Barbados.Material. Hundreds of specimens with excellent pres-ervation. Remarks. The species was first described from the Middle Eocene of Northeast Bulgaria in Avren and Aladan Formations (Dzhuranov, Darakchieva, 1986). The species is characterized by its globular test, thick calcite crust that covers and closes pores, a moderately elevated trochospire, and the heavy build-up of calcite crust surrounding the umbilicus. Discussion. The thick calcite crust led Beckmann (1953) to place his new species senni in the genus Sphaeroidinella. Bolli (1957a) placed Beckmann’s

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species in genus Globigerina and showed that it had a Lower to Middle Eocene range. Subsequently, senni has been placed in Globigerinatheka (Fleisher, 1974), tentatively in Subbotina (Poore, Brabb, 1977), and in Muricoglobigerina (Blow, 1979). Fleisher (1974) described Subbotina kiersteadae from the same sec-tion in which he identified senni and regarded it as the ancestral species of G. senni. The holotype of S. kier­steadae is a specimen from which the ultimate cham-ber is broken off. When present it would have covered the umbilical aperture as in senni. The test wall shows the typical encrustation of senni surrounding the um-bilicus. It is regarded as a junior synonym of senni (Pearson et al., 2006).Distiribution. The species appeared in the Lower Eocene Аcarinina pentacamerata Е6 zone (Berggren, Pearson, 2005) and persisted to the end of the Middle Eocene Morozoveloides crassatus Е13 zone (Berggren, Pearson, 2005). Global in low to mid latitudes. Occurrence. In Lom depression the species was es-tablished in the sediments of clay-marl formation, Avren Formation and marl-limestone formation in boreholes Р-2 Komoshtitsa (1110–1160 m – E6–7 zone), Р-3 Komoshtitsa (1120–1180 m – E7 zone), Р-1 Dalgodeltsi (1080–1370 m – E6, E7 zones), С-6 Oryahovo (326–375 m – E8–10, E11 zones), C-7 Oryahovo (300 m – E7b zone), С-11 Oryahovo (425–445 m – E8, E9–10, E11 zones).

Subbotina triangularis (White, 1928)(Plate III, 1–2)

1928. Globigerina triangularis sp. n.; White, p. 195, pl. 28, fig. la–c.

1957c. Globigerina triangularis White; Bolli, p. 71, pl. 15, figs. 12–14.

1970a. Globigerina triangularis White; Shutskaya, p. 104, pl. 3, fig. 5a–c.

1970b. Globigerina triangularis White; Shutskaya, pp. 118–120, 214, pl. 20, fig. 7a–c, p. 220, pl. 23, fig. la–c, p. 224, pl. 25, fig. la–c (non pl. 17, fig. 14a–c = Subbotina triloculinoides).

1970b. Globigerina pseudotriloba White; Shutskaya (non White, 1928), pp. 118–120, 216, pl. 21, fig. 2a–c, (non p. 210, pl. 18, fig. 6a–c).

1970b. Globigerina uruchaensis sp. n.; Shutskaya, pp. 118–120, 214, pl, 20, fig. lla–c, p. 216, pl. 21, fig. 7a–c (holotype refigured), p. 222, pl. 24, fig. la–c (given as Globigerna uruchensis in text).

1970a. Globigerina gerpegensis sp. n.; Shutskaya, p. 104, pl. 3, fig. 3a–c (holotype).

1975. Subbotina triangularis (White); Toumarkine (non White, 1928), pp. 737, 742, pl. 1, figs. 3, 4.

1979. Subbotina triangularis triangularis (White); Blow, pp. 1281–1284, pl. 91, figs. 7, 9, pl. 98, fig. 6, pl. 107, figs. 8, 9.

1990. Subbotina triangularis (White); Stott and Kennett (non White, 1928), p. 559, pl. 3, fig. 12.

1991a. Subbotina triangularis (White); Huber (non White, 1928), p. 441, pl. 5, fig. 4.

1991b. Subbotina triangularis (White); Huber (non White, 1928), p. 461, pl. 3, fig. 19.

1994. Subbotina triangularis (White); Juranov, p. 12, pl. 1, figs. 7, 8.

1997. Subbotina triangularis (White); Berggren and Norris, p. 81, pl. 5, figs. 1, 5, 9.

1999. Subbotina triangularis (White); Оlsson et al., p. 30, pl. 26, figs. 1–13.

Nomenclature. Holotype (Columbia University Pale-on tology Coll., No. 19881) is the specimen desig-nated by White (1928) from the Paleocene in Velasco Formation, Mexico. Material. Few specimens with poor preservation. Remarks The species was first described from the Middle Paleocene of Eastern Stara Planina in the Emine Formation (Juranov, 1994) and it is also known from the Byala Formation (Juranov, 1983).Discussion. Shutskaya’s (1970a, b) references to pseu­dotriloba, triangularis, uruchaensis, and gerpegensis are all considered synonymous with Subbotina trian­gularis. The criteria she provided to distinguish these forms and her text-illustrations are insufficient for consistent discrimination. Distribution. The species has global distribution in the low to middle latitudes. It appeared in the Lower Paleocene Praemurica uncinata P2 zone (Berggren, Pearson, 2005) and persisted to the end of the Upper Paleocene–Lower Eocene Morozovella velascoensis P5 zone (Berggren, Pearson, 2005). Occurrence. In Lom depression the species was estab-lished in the sediments of limestone-marl formation and Komarevo Formation in boreholes Р-1 Kovachitsa (1080 m – P5 zone), Р-3 Komoshtitsa (1360–1400 m – P4 zone), Р-1 Dalgodeltsi (1430–1480 m – P4 zone), С-6 Oryahovo (453.5–465 m – P4 zone).

Subbotina triloculinoides (Plummer, 1926)(Plate III, 3–4)

1926. Globigerina triloculinoides sp. n.; Plummer, p. 134, pl. 8, fig. 10a, b.

1928. Globigerina pseudotriloba sp. n.; White, p. 194, pl. 27, fig. 17a, b.

1953. Globigerina triloculinoides Plummer; Subbotina, p. 82, pl. 11, fig. 15c, pl. 12, figs. la–2c.

1957c. Globigerina triloculinoides Plummer; Bolli, p. 70, pl. 15, figs. 18–20, non pl. 17, figs. 25, 26 (= Para­subbotuna pseudobulloides).

1957. Globigerina triloculinoides Plummer; Loeblich and Tappan, p. 183, pl. 40, fig. 4a–c, pl. 41, fig. 2a–c, pl. 42, fig. 2a–c, pl. 43, fig. 5a–c, fig. 9a–c, pl. 45, fig. 3a–c, pl. 49, fig. 2a–c (non pl. 46, fig. 1a–c, pl. 47, fig. 2a–c, pl. 52, figs. 3–7, pl. 56, fig. 8a–c, pl. 62, figs. 3, 4).

1957. Globigerina inaequispira Subbotina; Loeblich and Tappan (non Subbotina, 1953), p. 181, pl. 52, fig. la–c.

1963. Globigerina triloculinoides Plummer; Gohrbandt, pp. 42, 43, pl. 1, figs. 1–3.

1970b. Globigerina triloculinoides Plummer; Shutskaya, pp. 118–120, 210, pl. 18, fig. la–c, p. 212, pl. 19, fig. 3a–c, p. 216, pl. 21, fig. 5a–c; p. 220, pl. 23, fig. 12a–c.

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PLATE III ТАБЛИЦА III

89

1975. Globigerina triloculinoides Plummer; Stainforth et al., p. 234, fig. 92: 1 (from Bolli, 1957a, pl. 15, figs. 18–20), 92: 2–6.

1978. Globigerina triloculinoides Plummer; Toumarkine, p. 698, pl. 1, figs. 3–5.

1979. Subbotina triloculinoides triloculinoides (Plummer); Blow, pp. 1287–1292, pl. 74, fig. 6, pl. 80, fig. 1, pl. 98, fig. 7, pl. 238, fig. 5, pl. 248, figs. 9, 10, pl. 255, fig. 9, pl. 257, fig. 9.

1990. Subbotina triloculinoides (Plummer); Stott and Kennett, p. 559, pl. 2, fig. 12.

1991b. Subbotina triloculinoides (Plummer); Huber, p. 461, pl. 3, fig. 19.

1994. Subbotina triloculinoides (Plummer); Juranov, p. 13, pl. 1, fig. 9, pl. 2, fig. 1.

1997. Subbotina triloculinoides (Plummer); Berggren & Norris, pl. 4, figs. 1–3, 5–7, 9, 10, 19, 21, 22.

Nomenclature. The holotype (Walker Museum Coll., No. 33076, Station 23, now in the Field Museum, Chicago) was designated by Plummer (1926) from the Paleocene of Wills Point Formation, Midway Group, Navarro Co., Texas Station 23.

Material. Dozens of specimens with poor to good preservation.Remarks. The species was first described from the Lower and Middle Paleocene of Northeastern Bulgaria in the Emine Formation (Juranov, 1994). It is also widely known from the Paleocene of Lom de-pression (Caneva, Vapcarova, 1961; Tsaneva, 1963, 1964), Byala Formation (Trifonova, 1959; Juranov, 1983) and from the the Paleocene near the village of Kladorub (Valchev, Juranov, 2006).Discussion. Subbotina triloculinoides and Parasub­botina pseudobulloides (Plummer), are probably one of the most cited, yet most frequently misidentified, taxa of the Paleocene. Although S. triloculinoides has a strongly cancellate wall texture, its does not pos-sess the symmetrical, coarsely cancellate wall of the cancellata-velascoensis lineage. The ancestral S. trivi­alis is more weakly cancellate, and S. triangularis has an asymmetrical cancellate surface with distinct spine collars.Distribution. Subbotina triloculinoides appeared in the Lower Paleocene Subbotina triloculinoides P1b

PLATE III

1, 2. Subbotina triangularis (White, 1928). С-6 Oryahovo, 465 m, sample 40, Komarevo Formation, Upper Paleocene, P4 zone; 1, spiral view, SEM x 200; 2, umbilical view, SEM x 200.3, 4. Subbotina triloculinoides (Plummer, 1926). С-6 Oryahovo, 453 m, sample 53, Komarevo Formation, Lower Eocene, Е2 zone; 3, umbilical view SEM x 230; 4, spiral view SEM x 170. 5. Subbotina velascoensis (Cushman, 1925). С-6 Oryahovo, 455 m, sample 39, Komarevo Formation, Upper Paleocene, P4 zone; umbilical view, SEM x 230. 6, 7. Subbotina yeguaensis (Weinzierl & Applin, 1929). С-6 Oryahovo, 347 m, sample 28, Avren Formation, Middle Eocene, Е8–10 zone; 6, umbilical view, SEM x 170; 7, spiral view, SEM x 150.8, 9. Globigerinatheka index (Finlay, 1939). С-6 Oryahovo, 250 m, sample 24, Avren Formation, Middle Eocene, E11 zone; 8, umbilical view, SEM x 150; 9, spiral view, SEM x 130.10, 11. Globigerinatheka korotkovi Keller, 1946. С-6 Oryahovo, 250 m, sample 24, Avren Formation, Middle Eocene; E11 zone; 10, apertures, SEM x 170; 11, spiral view, SEM x 150.12, 13. Globigerinatheka subconglobata (Shutskaya, 1958). С-6 Oryahovo, 250 m, sample 24, Avren Formation, Middle Eocene; E11 zone; 12, SEM x 170; 13, SEM x 150.

ТАБЛИцА III

1, 2. Subbotina triangularis (White, 1928). С-6 Оряхово, 465 m, проба 40, Комаревска свита, Горен Палеоцен, зона P4; 1 – спирална страна, SEM x 200; 2 – пъпна страна, SEM x 200.3, 4. Subbotina triloculinoides (Plummer, 1926). С-6 Оряхово, 453 m, проба 53, Комаревска свита, Долен Еоцен, зона Е2; 3 – пъпна страна SEM x 230; 4 – спирална страна, SEM x 170. 5. Subbotina velascoensis (Cushman, 1925). С-6 Оряхово, 455 m, проба 39, Комаревска свита, Горен Палеоцен, зона P4; пъпна страна, SEM x 230. 6, 7. Subbotina yeguaensis (Weinzierl & Applin, 1929). С-6 Оряхово, 347 m, проба 28, Авренска свита, Среден Еоцен, зона Е8–10; 6 – пъпна страна, SEM x 170; 7 – спирална страна, SEM x 150.8, 9. Globigerinatheka index (Finlay, 1939). С-6 Оряхово, 250 m, проба 24, Авренска свита, Среден Еоцен, зона E11; 8 – пъпна страна, SEM x 150; 9 – спирална страна, SEM x 130.10, 11. Globigerinatheka korotkovi Keller, 1946. С-6 Оряхово, 250 m, проба 24, Авренска свита, Среден Еоцен, зона E11; 10 – апертури, SEM x 170; 11 – спирална страна, SEM x 150.12,13. Globigerinatheka subconglobata (Shutskaya, 1958). С-6 Оряхово, 250 m, проба 24, Авренска свита, Среден Еоцен, зона E11; 12 – SEM x 170; 13 – SEM x 150.

Scale bar – 100 μm

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subzone (Berggren, Pearson, 2005) and persisted to the Upper Paleocene Globanomalina pseudomenar-dii P4 zone (Berggren, Pearson, 2005). The LAD of S. triloculinoides is somewhat unclear, as Ollson et al. (1999) did not find it above zone P4 and believed that stratigraphically the species is restricted in the Paleocene. Worldwide distribution in the low to high latitudes. Occurrence. In Lom depression the species was es-tablished in the sediments of the limestone-marl for-mation and Komarevo Formation in boreholes R-1 Asparuhovo (1218–1414 m – P1c–P3a, P4 zones), R-3 Asparuhovo (1325–1509 m – P1c–P3a, P3b, P4 zones), R-5 Asparuhovo (1176–1307 m – P1c–P3a zone), R-1 Dalgodeltsi (1460–1480 m – P4 zone), С-6 Oryahovo (475 m – P4 zone).

Subbotina velascoensis (Cushman, 1925)(Plate III, 5)

1925. Globigerina velascoensis sp. n.; Cushman, p. 19, pl. 3, fig. 6a–c.

1928. Globigerina velascoensis Cushman; White, p. 196, pl. 28, fig. 2a, b.

1928. Globigerina velascoensis var. compressa subsp. n.; White, p. 196, pl. 28, fig. 3a, b.

1957c. Globigerina velascoensis Cushman; Bolli, p. 71, pl. 15, figs. 9–11.

1957. Globigerina triloculinoides Plummer; Loeblich and Tappan (non Plummer, 1926), p. 183, pl. 52, figs. 3–7, pl. 62, fig. 3a, b.

1963. Globigerina velascoensis Cushman; Gohrbandt, p. 47, pl. 2, figs. 1–3.

1970a. Globigerina velascoensis Cushman; Shutskaya, p. 94, pl. 4, figs. 3a–4c, 6a–c.

1970b. Globigerina velascoensis Cushman; Shutskaya, pp. 118–120, 176, pl. 1, fig. 3a–c, p. 178, pl. 2, fig. 5a–c, p. 188, pl. 7, fig. 7a–c, p. 190, pl. 8, fig. 8a–c, p. 218, pl. 22, fig. 4a–c, p. 224, pl. 25, fig. 2a–c, p. 226, pl. 26, fig. 6a–c.

1970a. Globigerina nana Khalilov; Shutskaya, p. 90, pl. 2, fig. 2a–c.

1975. Globigerina velascoensis Cushman; Stainforth et al., pp. 239, 240, text-fig. 96: 1 (illustration of Bolli, 1957a, pl. 15, fig. 9–11 prefigured), 96: 2–4.

1979. Subbotina velascoensis (Cushman); Blow, pp. 1292–1294, pl. 98, fig. 9.

1991a. Subbotina velascoensis (Cushman); Huber, p. 441, pl. 4, figs. 11, 12.

1994. Subbotina velascoensis (Cushman); Juranov, p. 16, pl. 2, fig. 9.

1997. Subbotina velascoensis (Cushman); Berggren and Norris, pl. 5, figs. 2, 6, 7, 11.

1999. Subbotina velascoensis (Cushman); Оllson et al., p. 33, pl. 29, figs. 1–12.

Nomenclature. The holotype (U. S. National Museum of Natural History, Cushman Coll., No. USNM CC4348) is the specimen designated by Cushman (1925) from the Paleocene Velasco Formation, Tamalte Arroyo, Hacienda el Limon, San Luis Potosi, Mexico.

Material. Dozens of species with bad or good preser-vation.Remarks. The species was first described from the Lower Eocene of Eastern Stara Planina in the Emine Formation (Juranov, 1994).Discussion. Although the holotype is deformed, Bolli (1957a) defined the concept of this species, which is followed herein. The species was described from the Velasco Shale from which White (1928) illustrated better preserved specimens that he identified with Cushman’s species. White’s concept was followed by Bolli. White’s figures, although drawings, illus-trate a quadrate-shaped test with much compressed chambers. Furthermore, his drawings clearly indicate a symmetrical, coarsely cancellate test wall. Cushman (1925) in his description referred to an evenly retic-ulate wall, which suggests that he observed the wall texture that characterizes this species.Distribution. Subbotina velascoensis first appeared in Аcarinina subsphaerica P4b subzone (Berggren, Pearson, 2005) and persisted until Pseudohastigerina wilcoxensis/Morozovella velascoensis E2 zone (Berg-gren, Pearson, 2005). Essentially a worldwide distri-bution in the low to middle latitudes, with preferential development in the middle to higher latitudes as is common with the subbotinids. Occurrence. In Lom depression the species was es-tablished in the sediments of limestone-marl forma-tion, Komarevo Formation and marl-limestone for-mation in boreholes R-1 Kovachitsa (1080 m – P5 zone), R-3 Komoshtitsa (1330–1400 m – P4 zone), R-1 Dalgodeltsi (1420–1460 m – P4, E2 zones), С-6 Oryahovo (439–465 m – P4, E2 zones), С-7 Oryahovo (410 m – P5 zone), C-11 Oryahovo (555–625 m – P4–E2 zone).

Subbotina yeguaensis (Weinzierl and Applin, 1929)(Plate III, 6–7)

1929. Globigerina yeguaensis sp. n.; Weinzierl and Ap-plin, p. 409, pl. 43, fig. 1a–b.

1953. Globigerina pseudoeocaena var. pseudoeocaena subsp. n.; Subbotina, p. 81, pl. 11, fig. M (partim; not pl. 5, figs. 1a–2c = Subbotina eocaena; not pl. 5, fig. 6a–c = Subbotina corpulenta).

1957a. Globigerina yeguaensis Weinzierl and Applin; Bolli, p. 163, pl. 35, fig. 15a–c (partim; not pl. 35, fig. 14a–c).

1962. Globigerina linaperta pseudoeocaena Subbotina; Blow and Banner, p. 87, pl. 11, fig. M.

1969. Globigerina yeguaensis Weinzierl and Applin; Blow, p. 319, pl. 3, figs. 12–14 (holotype reillus-trated).

1979. Globigerina yeguaensis Weinzierl and Applin; Blow, p. 1313, pl. 3, figs. 12–14 (holotype reillus-trated).

1979. Subbotina pseudoeocaena (Subbotina); Blow, p. 1279, pl. 187, figs. 8, 9.

1979. Subbotina angiporoides lindiensis subsp. n.; Blow, p. 1253, pl. 244, figs. 8–9.

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1983. Globigerina pseudoeocaena Subbotina.; Krashenin-nikov and Basov, p. 838, pl. 2, figs. 1–3.

1985. Globigerina yeguaensis Weinzierl and Applin; Bolli and Saunders, p. 180, figs. 13–23a, b (holotype reil-lustrated).

1991a. Subbotina yeguaensis (Weinzierl and Applin); Hu-ber, p. 441, pl. 5, fig. 2.

1999. Subbotina yeguaensis (Weinzierl and Applin); Da-rakchieva, p. 49.

2001. Subbotina yeguaensis (Weinzierl and Applin); War-raich and Ogasawara, p. 49, fig. 14: 4, 8, 12.

2006. Subbotina yeguaensis (Weinzierl and Applin); Pearson et al., p. 152, pl. 6.18, figs. 1–16 (pl. 6.18, figs. 1–3: SEM’s of holotype of Globigerina yegua­ensis Weinzierl and Applin).

Nomenclature. The holotype (Smithsonian Museum of Natural History, Washington, D. C., No. USNM CC12210) is the specimen designated by Weinzierl and Applin (1929) from the Middle Eocene, Yegua Formation, subsurface, Louisiana. Material. Hundreds of specimens with excellent pres-ervation.Description. Normal perforate, symmetrically cancel-late, sacculifer-type wall texture, spinose. Test mod-erately elevated, trochospiral, lobulate in outline, with 3½ globular, slightly embracing chambers in ultimate whorl, increasing moderately in size, ultimate cham-ber may be equal to or smaller in size than penulti-mate chamber, sutures moderately depressed, straight; umbilicus small, enclosed by surrounding chambers, aperture umbilical, bordered by a somewhat broad lip that tapers both anteriorly and posteriorly.Remarks. The species is known from the Lower Eocene in Eastern Stara Planina, Dvoynitsa Formation (Darakchieva, 1999). Here the species is first de-scribed in Bulgaria.Discussion. The holotype of Subbotina pseudoeocae­na (Subbotina) which is described from the Lower–Middle Eocene of the Northern Caucasus has the morphologic characteristics of S. yeguaensis and is considered as a junior synonym, as is Subbotina angi­poroides lindiensis of Blow (1979).Distribution. Global in low to high latitudes. Sub­botina yeguaensis first appeared in the end of the Lower Eocene А. cuneicamerata Е7 zone (Berggren, Pearson, 2005) and persisted to the end of the Upper Eocene Hantkenina alabamensis Е16 zone (Berggren, Pearson, 2005). Occurrence. The species was established in the sedi-ments of marl-limestone formation, Avren Formation, limestone-marl formation and clay-marl formation in boreholes С-10 Leskovets (274–343 m – E7–9 zone), R-1 Kovachitsa (930–980 m – E5–6), R-2 Komoshtitsa (900–1160 m – E6–7), R-3 Komoshtitsa (780–1180 m – E7), R-1 Dalgodeltsi (1080–1430 m – E2, E5, E6, E7 zones), С-6 Oryahovo (253–435 m – E6–7, E8–10, E11 zones), С-7 Oryahovo (230–360 m – E7a, E7b, E8–10, E11 zones), С-8 Oryahovo (420–490 m – E7–11 zone), С-11 Oryahovo (408–495 m – E5–E7a, E7b, E8, E9–10, E11 zones).

Genus Globigerinatheka Brönnimann, 1952Type species. Globigerinatheka barri Brönnimann, 1952.

Globigerinatheka index (Finlay, 1939)(Plate III, 8–9)

1939. Globigerinoides index sp. n.; Finlay, p. 125, pl. 14, figs. 85–88.

non 1953. Globigerinoides index Finlay; Beckmann, pl. 25, fig. 14 (= G. semiinvoluta).

non 1957a. Globigerapsis index (Finlay); Bolli, p. 165, pl. 36, figs. 14a–18b (= G. suhconglobata).

1958. Globigerinoides index Finlay; Hornibrook, pl. 1, figs. 11–13 (redrawn holotype), fig. 14 (redrawn paratype).

1958. Globigerinoides conglobatus Brady; Shutskaya, pl. 2, fig. 1, fig. 2 [not Brady, 1879].

p 1962. Globigerapsis index (Finlay); Blow and Banner, pl. 15, fig. G (not fig. H = G. kugleri).

non 1969. Globigerapsis index (Finlay); Blow, pl. 27, figs. 1–2 (= G. korotkovi).

1971. Globigerinatheka (Globigerapsis) index index (Finlay); Jenkins, pp. 187–188, pl. 22, figs. 641–643 (redrawn holotype), fig. 644 (redrawn paratype), fig. 645.

1975. Globigerinatheka index index (Finlay); Toumar-kine, pl. 4, figs. 6, 7.

1975. Globigerinatheka index (Finlay); Stainforth et al., fig. 56.1, 3, fig. 56.2 (from Bolli, 1972), fig. 56.6 (from Blow and Banner, 1962).

1978. Globigerinatheka index index (Finlay); Toumar-kine, pl. 5, figs. 3–5, 7–9, figs. 1, 6.

1979. Globigerapsis index (Finlay); Blow, pl. 27, figs. 1, 2, pl. 192, fig. 1, pl. 174, figs. 1–4, 6, 8, pl. 181, fig. 1, pl. 183, figs. 1, 2, pl. 186, figs. 2, 3.

1983. Globigerapsis index Finlay; Krasheninnikov and Basov, pl. 7, figs. 2–3, pl. 7, figs. 4–5.

1990. Globigerina index (Finlay); Stott and Kennett, p. 559, pl. 7, fig. 8.

1991a. Globigerinatheka index (Finlay); Huber, p. 440, pl. 7, figs. 17, 22.

1991. Globigerinatheka index (Finlay); Van Eijden and Smit, pl. 3, figs. 6–8.

p 1991. Globigerinatheka sp. cf. index (Finlay); Van Eijden and Smit, pl. 3, fig. 4, fig. 5 (not fig. 9).

p 1992. Globigerinatheka index (Finlay); Berggren, pl. 3, figs. 10–11 (not fig. 9 = G. luterbacheri).

non 1992. Globigerinatheka index index (Finlay); Berg gren, pl. 3, figs. 5–6 (= G. tropicalis), fig. 8 (= G. korot­kovi).

1995. Globigerinatheka index index (Finlay); Poag and Commeau, pl. 5, fig. 27.

2006. Globigerinatheka index (Finlay); Pearson et al., p. 187, pl. 7.5, figs. 1–20.

Nomenclature. The holotype (New Zealand Geological Survey Coll.) was designated by Finlay (1939) from the Hampden section (5179A, beach 1 mile North of Kakaho Creek). Material. Few dozens of specimen with excellent preservation.Description. Spinose, cancellate, frequently encrusted, with mainly cylindrical pores. Test slightly elongate,

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subrectangular in outline, rather compact, broadly rounded. Early chambers poorly visible, arranged in a low trochospire of possibly 2–3 whorls, with the last whorl consiting of 3 inflated chambers at least twice as large as earlier chambers, antepenultimate and pen-ultimate chambers of almost equal size separated by a vertical suture in umbilical view, the last chamber making almost one-half of the whole test; sutures of the inner chambers poorly visible, possibly straight or slightly curved, sutures in the last whorl distinct, deeply incised, straight and radial; primary aperture, umbilical, a rather high and large, symmetrical arch, at the base of the last chamber frequently bordered by a thick lip, two medium-sized, semicircular arched, secondary apertures at the base of the last chamber above the sutures of previous chambers. Bullae are not common. Remarks. The species is first described in Bulgaria.Discussion. At high latitudes (including the type local-ity), specimens of G. index with typically incised su-tures commonly display poorly developed secondary spiral apertures or are even devoid of them (Pearson et al., 2006).Distribution. The LAD of G. index served to place the boundary between Eocene and Oligocene at high southern latitudes (Jenkins, 1971). Its strati-graphic range spans from Globigerinatheka kugleri/Morozovella aragonesis Е9 zone (Berggren, Pearson, 2005) to Globigerinatheka index E15 zone (Berggren, Pearson, 2005). Cosmopolitan.Occurrence. Avren Formation: С-6 Oryahovo (250–328 m – E11 zone), С-8 Oryahovo (420–430 m – E11 zone), С-11 Oryahovo (430 m – E11 zone). Middle Eocene.

Globigerinatheka korotkovi Keller, 1946(Plate III, 10–11)

1946. Globigerinatheka korotkovi sp. n.; Keller, p. 89, pl. 2, figs. 14–16.

1953. Globigerinatheka korotkovi Keller; Subbotina, p. 90, pl. 14, fig. 1a, b (redrawn holotype).

1969. Globigerapsis index (Finlay); Blow, pl. 27, figs. 1–2 [not Finlay, 1945].

1972. Globigerinatheka index rubriformis Subbotina; Bolli, pl. 1, figs. 5, 11–12.

1975. Globigerinatheka index rubriformis Subbotina; Toumarkine, pl. 4, fig. 8.

1975. Globigerinatheka index (Finlay); Stainforth et al., fig. 56: 8a, b (from Blow, 1969, pl. 27, figs. 1–2).

1975. Globigerinatheka subconglobata subconglobata Shutskaya; Toumarkine, pl. 4, fig. 2 [not Shutskaya, 1958].

1978. Globigerinatheka index rubriformis Subbotina; Toumarkine, pl. 4, figs. 17–20.

1978. Globigerinatheka index tropicalis Blow and Banner; Toumarkine, pl. 4, fig. 16 [not Blow and Banner, 1962].

1979. Globigerapsis kugleri Bolli et al.; Blow, pl. 181, fig. 3 [not Bolli, Loeblich and Tappan, 1957].

1992. Globigerinatheka index (Finlay); Berggren, pl. 3, fig. 8 [not Finlay, 1945].

1999. Globigerinoides rubriformis (Subbotina, 1953); Da-rak chieva, p. 52.

2006. Globigerinatheka korotkovi Keller; Pearson et al., p. 188, pl. 7.6, figs. 1–16 (pl. 7.6, figs. 1, 2: reil-lustration of holotype of Globigerinoides korotkovi Keller).

Nomenclature. Holotype (State Institute of Sciences, Moscow, Coll. 2831, No. 98) is the specimen desig-nated by Keller (1946), which was derived from the Upper Cretaceous, base Senonian, Gueniokh horizon, River Khosta, near Sotchi, Western Caucasus. Material. Few specimens with good preservation. Description. Spinose, cancellate, moderately en-crusted type of wall. Test shape sac-like consisting of 2–3 whorls arranged in a high trochospire; chambers subglobular with three chambers in the last whorl; su-tures distinct, depressed, straight to slightly curved; peripheral outline rather compact; primary aperture a medium-sized subcircular arch at the junction of the sutures of the last three chambers with one subcircu-lar secondary aperture almost identical to the primary one; other much smaller secondary apertures may be present on the spiral side of the previous chambers. Remarks. The species is known from the Upper Eocene in North Bulgaria (Darakchieva, 1999) under the name Globigerinoides rubriformis (Subbotina, 1953). Here the species is first described in Bulgaria.Discussion. Keller (1946), in the original discus-sion, stated that “the present species differs from the Paleogene Globigerinoides conglobatus Brady from the Upper Eocene of the Sotchi region in its much smaller dimensions in the single type of structure shown by the representatives of this species.“ Keller (1946) also em-phasized that his species korotkovi is represented only as “regularly constructed forms“ contrary to the high morphological variations observed in what he called the Paleogene Globigerinoides conglobatus. Distribution. The species is commonly found in low and middle latitudes. Its stratigraphic range spans from Globigerinatheka kugleri/Morozovella aragone-sis Е9 zone (Berggren, Pearson, 2005) to Hantkenina alabamensis Е15 zone (Berggren, Pearson, 2005). Occurrence. Avren Formation: С-6 Oryahovo (250 m – E11 zone), С-11 Oryahovo (430–435 m – E11 zone). Middle Eocene.

Globigerinatheka subconglobata (Shutskaya, 1958)(Plate III, 12–13)

1957a. Globigerapsis index (Finlay); Bolli, p. 165, pl. 36, fig. 14a–b [not Finlay, 1939].

1958. Globigerinoides subconglobatus var. subcongloba­tus subsp. n.; Shutskaya, p. 86 pl. 1, figs. 4–11 (no designated holotype, lectotype designated by Bolli, 1972, as the specimen in fig. 8).

1972. Globigerinatheka subconglobata subconglobata (Shut s kaya); Bolli, p. 134, text-figs. 43–46 (text-

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fig. 44 lectotype = pl. 1, fig. 8 of Shutskaya, 1958), pl. l, figs. 8–10, 15–16.

1975. Globigerinatheka index (Finlay); Stainforth et al., fig. 56: 5, 7, 9 (from Bolli, 1972, pl. l, figs. 2, 6, 7) [not Finlay, 1939].

1975. Globigerinatheka subconglobata subconglobata (Shut skaya); Toumarkine, pl. 4, fig. 1.

1975. Globigerinatheka subconglobata (Shutskaya); Stain-forth et al., fig. 90: 1–5 (from Bolli, 1972), fig. 90: 6–11 (from Shutskaya, 1958).

1978. Globigerinatheka subconglobata subconglobata (Shutskaya); Toumarkine, pl. 3, figs. 1–3.

1978. Globigerinatheka mexicana mexicana (Cushman); Toumarkine, pl. 4, fig. 5.

1986. Globigerinatheka subconglobata micra (Shutskaya); Dzhuranov and Darakchieva, p. 9, pl. 2, fig. 3 (in Bulgarian).

1991. Globigerinatheka subconglobata (Shutskaya); Van Eijden and Smit, p. 111.

1995. Globigerinatheka subconglobata (Shutskaya); Poag and Commeau, pl. 4, figs. 18–19.

2006. Globigerinatheka subconglobata (Shutskaya); Pear-son et al., p. 200, pl. 7.10, figs.1–20 (pl. 7.10, fig. l: reillustration of lectotype of Globigerinoides sub­conglobatus var. subconglobatus Shutskaya).

Nomenclature. The lectotype (Geological Institute of Academy of Sciences of the USSR Coll., Moscow) was designated by Bolli (1972). Material. Hundreds of specimens with excellent pres-ervation.

Remarks. The species was first described from the Middle Eocene of Northeastern Bulgaria in the upper part of Avren Formation, borehole C-153a Gurkovo (Dzhuranov, Darakchieva, 1986). It is also known from the Eocene of Lom depression, borehole C-11 Oryahovo (Tsaneva, 1963).Discussion. Shutskaya (1958) first described and il-lustrated this taxon as Globigerinoides subcongloba­tus even though she indicated Khalilov as its author in referring to a manuscript which has never been published. Shutskaya did not indicate the holotype but later Bolli (1972) selected as a lectotype the speci-men that Shutskaya (1958) illustrated in her pl. 1, fig. 8. The figures of the specimen illustrated by Bolli (1957a) as G. index (pl. 36, fig. 14a–b) appears to be one of the best representatives of G. subconglobata. Globigerinatheka subconglobata is characterized by a longer and much higher spire, more numerous cham-bers (four in the last whorl), a small flattened final chamber not enveloping or covering previous ones.Distribution. Globigerinatheka subconglobata is globally spread from the beginning of Guembilitriodes nuttalli Е8 zone (Berggren, Pearson, 2005) to the end of Morozovelloides crassatus Е13 zone (Berggren, Pearson, 2005). Occurrence. Avren Formation: С-6 Oryahovo (250–328 m – E11 zone), С-8 Oryahovo (420–430 m – E11 zone), С-11 Oryahovo (425–439 m – E9–E10 and E11 zones). Middle Eocene.

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Постъпила на 18.09.2017 г., приета за печат на 14.11 .2017 г.Отговорен редактор Борис Вълчев