PALAEONTOLOGICAL STUDY - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/73160/13/13...Benthic foraminifera have been divided into, morphogroups based on the test shape and these

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CHAPTER 5

PALAEONTOLOGICAL STUDY

5. 1: Introduction

The three limestone members of the Shella Formation viz. Lakadong

Limestone, Umlatdoh Limestone and Prang Limestone are moderate to highly

fossiliferous.The fossil assemblage is represented by large and micro benthic

foraminiferas along with the calcareous algeae. Moreover, some ill-preserved

mollascan and coral shells are also seen mostly in shell partings. The fossil

assemblage large and micro foraminiferas and calcareous algeae are useful for

dating and interpreting their depositional environment.

Lakadong Limestone is characterizing by species of Ranikothalia,

Miscellanea, Glomalveolina, Discocyclina, microforms of Nummulites etc. Very few

Milioids viz Quinqueloqulina, Triloculina, Textularia are present in various

proportions. Moreover, this member also contains some important calcareous algae

fossils.

Miliods and Fasciolites represent the middle limestone unit. Amongst

Miliods and Alviolina is the most abundant genus, others are Quinqueloculina,

Triloculina and Textularia. A few Nummulitic genera are also present. Amongst

Fasciolites, Fasciolite elliptica is the main genus.

The uppermost member of the Shella Formation viz Prang Limestone

Member is characterizing by the abundance of larger and micro forams of

Nummulites, Discocyclina, Assilina, etc. Pellatispira is the only genus present in this

member. Moreover, some important algae fossils also characterize this member.

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5.2 Method of study

The method of study of fossils can be broadly classified as-(A) Field study.

(B) Laboratory study.

Field study:

For the purpose of field study, the following steps preceded -

(a) Preparation of base map 1:50,000 scale. (b) The samples collected from

the area under study include mainly hard, compact limestone, when collecting the

samples from the outcrop, care was taken that the rock is unweathered and

uncontaminated by recent vegetation or by hammer, chisels trowels and the hike.

Clear polythene sample bags with suitable closure device were used to keep the

collected samples. (c) The photographs are taken in the field.

Laboratory study:

The collected limestone sample is analyz for foraminifar and calcareous

algae study. Majority of the sample were yield rich foraminiferal assemblage and

calcareous algae study with more or less preservations.

Preparation of thin sections of fossils-

After the recovery of the individual tests from samples, thin sections were

made following the conventional methods. To study the internal structure of the

fossils, both axial and equatorial sections are prepared.

At first, the tests mounted on a slide by using Canda-balsam. For

preparation of equatorial sections, tests are mounted horizontally on the glass slide

and then grinded on a glass plate using finer abrasive powder (carborandum powder)

to reach the centre of the tests. Then again, the same tests are grinded by placing the

already grinded face as the glass slide to reach the centre of the tests. In axial section

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same principle is adopted except in the section the tests are mounted vertically on

the glass slide. Only one section can be prepared from one test. During this process,

a test is checked under microscope, time to time whether it is reaching the centre or

not. In the final stage 800 mesh, carborandum powder was used for grinding.

Usually a section of 0.3mm thick is best for study, cover slides is necessary in

preparing thin section for study.

5. 3: Microfauna: Foraminifera

The order foraminiferida or foraminifera as they are informally called

forams, the most important group of microfossils for two reasons: firstly, they are

abundant in rocks and there are numerous species; secondly, they provide valuable

information in the dating of strata and the reconstruction of sedimentary

environments.

Foraminifera have been utilised for biostratigraphy for many years, and they

have proven invaluable in palaeoenvironmental reconstructions most recently for

palaeoceanographical and palaeoclimatological purposes. For example,

palaeobathymetry where assemblage composition is used and palaeotemperature

where isotope analysis of foraminifer tests is a standard procedure. In terms of

biostratigraphy, foraminifera have become extremely useful, different forms have

shown evolutionary bursts at different periods and generally, if one form is not

available to be utilized for biostratigraphy another is. For example, preservation of

calcareous walled foraminifera is dependent on the depth of the water column and

Carbonate Compensation Depth (CCD) (the depth below which dissolution of

calcium carbonate exceeds the rate of its deposition), if calcareous walled

foraminifera are therefore not preserved agglutinated forms may be. The oldest

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rocks for which foraminifera have been biostratigraphically useful are Upper

Carboniferous to Permian strata, which have been zoned using the larger benthic

fusulinids. Planktic foraminifera have become increasingly important

biostratigraphic tools, especially as petroleum exploration has extended to offshore

environments of increasing depths. The first and last occurrence of distinctive

"marker species" from the Cretaceous to Recent (particularly during the Upper

Cretaceous) has allowed the development of a well-established fine scale

biozonation. Benthic foraminifera have been used for palaeobathymetry to

reconstruct palaeodepths. For studies of relatively recent deposits simple comparison

to the known depth distribution of modern extant species is used. For older material

changes in species diversity, planktic to benthic ratios, shell-type ratios and test

morphology have all been utilized. Variations in the water temperature inferred from

oxygen isotopes from the test calcite can be used to reconstruct palaeoceanographic

conditions by careful comparison of changes in oxygen isotope levels as seen in

benthic forms (for bottom waters) and planktic forms (for mid to upper waters).

Benthic foraminifera have been divided into, morphogroups based on the test shape

and these groups used to infer palaeo-habitats and substrates; infaunal species

tending to be elongate and streamlined in order to burrow into the substrate and

epifaunal species tending to be more globular with one relatively flatter side in order

to facilitate movement on top of the substrate.

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5.3.1: Classification of Benthic Foraminifera

Foraminiferas classified primarily on the composition and morphology of the

test. Three basic wall compositions are recognised, organic (protinaceous

mucopolysaccharide i.e. the allogromina), agglutinated and secreted calcium

carbonate (or more rarely silica). Agglutinated forms, i.e the Textulariina, may be

composed of randomly accumulated grains or grains selected on the basis of specific

gravity, shape or size; some forms arrange particular grains in specific parts of the

test. Secreted test foraminiferas again subdivided into three major groups,

microgranular (i.e. Fusulinina), porcelaneous (i.e. Miliolina) and hyaline (i.e.

Globigerinina). Microgranular walled forms (commonly found in the late

Palaeozoic) are composed of equidimensional subspherical grains of crystalline

calcite. Porcelaneous forms have a wall composed of thin inner and outer veneers

enclosing a thick middle layer of crystal laths; they are imperforate and made from

high magnesium calcite. The hyaline foraminifera add a new lamella to the entire

test each time a new chamber is formed; various types of lamellar wall structure

have been recognized, the wall is penetrated by fine pores and hence termed

perforate. A few "oddities" are also worth mentioning, the Suborder Spirillinina has

a test constructed of an optically single crystal of calcite, the Suborder

Silicoloculinina as the name suggests has a test composed of silica. Another group

(the Suborder Involutina) have a two chambered test composed of aragonite. The

Robertinina also have a test composed of aragonite and the Suborder Carterina is

believed to secrete spicules of calcite which are then weakly cemented together to

form the test (Table 5.1).

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Table 5.1: Classification of Foraminifera (after Loeblich and Tappan, 1988)

Phylum - Sarcomastgophora,

Subphylum - Sarcodina,

Superclass - Rhizopoda,

Class - Granuloreticulosea,

Order - Foraminiferida, Eichwald, 1830

Suborder ALLOGROMINA, Loeblich and Tappan, 1961

Suborder FUSULINIINA, Wedekind, 1937

Suborder TEXTULARINIINA, Delage and He’rouard, 1896

Suborder INVOLUTININA, Hohenegger and Piller, 1977

Suborder CARTERRINA, Loeblich and Tappan, 1981

Suborder MILIOLINA, Delage and He’rouard, 1896

Suborder ROBERTININA, Loeblich and Tappan, 1984

Suborder SPIRILININA, Hohenegger and Piller, 1975

Suborder SILICOLOCULININA, Resig, Lowenstam, Echols, and Weiner, 1980

Suborder LAGENINA, Delage and He’rouard, 1896

Suborder GLOBIGERININA, Delage and He’rouard, 1896

Suborder ROTALIINA, Delage and He’rouard, 1896

The species of the familys of benthic foraminifera is available in the study area are

as follows-

Family Nummulitidae de Blainville, 1827

Family Miscellaneidae, Sigal, 1952

Family Textulariidae, Ehrenberg, 1838

Family Miliolidea, Hauerinidae Schwager, 1876

Family Hauerinidae Schwager, 1876

Family Alveolinidea Ehrenberg, 1839

Family Nummulitidae, Galloway, 1928

Family Discocyclinidae Galloway, 1928

Family Calcarinidae D'Orbigny, 1826

Family Rotalidae Ehrenberg, 1839

Family Soritidae Ehrenberg 1839

Family Fabulariidae Ehrenberg, 1839

Family Eponididae Hofker, 1951

Family Lepidorbitoididae Vaughan, 1933

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5.3.2: Distribution of foraminifera

The calcareous sediments of Shella Formation are rich in benthonic

foraminiferal assemblages. The assemblages contain Cenozoic foraminifera ranging

from Paleocene to Eocene. Both larger and micro-foraminifers were encountered

from the study area.

The Lakadong Limestone Member of the Sylhet Formation yielded a number

of foraminiferal assemblages. The typical Late Paleocene (Montian) foraminifera

Miscellanea miscella found to occur in this limestone member. The member is with

few Miliolids, which contain Quinqueloculina, Spiroloculina, Triloculina and

Textularia. Moreover, it is also rich in calcareous algae. Among other foraminifers,

Lokhartia haimei, Glomalveolina primaeva, Ranikothalia nuttalli etc. also found to

be present in this limestone member. These foraminiferal assemblages are yielded

by the exposed sequences in the study area.

The Umlatdoh Limestone Member is represented by typical early to middle

Eocene (Ypresian) fauna. It consists of only Fasciolites elliptica from bottom to top

of the member. Some forms of Miliolids are also found to occur in the member.

The uppermost member of the Sylhet Limestone Formation viz. the Prang

Limestone Member, is rich in middle Eocene (Lutetian) foraminiferal microfauna.

Among Discocyclines, Discocyclina pygmaea, and Discocylina omphalus found to

occur. The member has yielded a number of Nummulites like Nummulites obtusus,

Nummulites acutus Sowerby, Nummulites beaumonti D’Archiac and Haime and

Nummulites pengaronensis Verbeek etc. Moreover the member is also consisting of

Pellatispira madaraszi, Textularia sp. etc.

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Table 5.2: showing specise name availability (Index: ‘a’ - available)

Sl.No. and Specise name Lakadong

Limestone

Umlatdoh

Limestone

Prang

Limestone

1. Nummulites pengaronensis Verbeek, 1871 a

2. Nummulites acutus Sowerby, 1840 a

3. Nummulites millecaput Boubee, 1832 a

4. Nummulites globules Leymerie, 1846 a

5. Nummulites beaumonti d’Archiac and Haime 1853 a

6. Nummulites perforatus (de Montfort), Sengupta, 1965 a a

7. Nummulites pratti d'Archiac and Haime, 1853 a a

8. Nummulites mamillatus (Fichtel and Moll) a a

9. Nummulites preaturicus Schaub, 1962 a

10. Nummulites obtusus Sowerby, 1840 a

11. Ranikothalia nuttalli (Davies) Nagappa, 1959 a

12. Ranikothalia sindensis (Davies) Caudri, 1944 a

13. Ranikothalia sp. a

14. Miscellanea sp. a

15. Miscellanea juliettae Leppig, 1988 a

16. Miscellanea yvettae Leppig, 1988 a

17. Glomalveolina primaevea Reichel, 1937 a

18. Glomalveolina primaevea Hottinger, 1962 a

19. Glomalveolina levis (Hottinger, 1960) a

20. Textularia sagittula Defrance, 1824 a

21. Textularia barretti Jones and Parker, 1871 a

22. Textularia biserial, de Blainville, 1824 a

23. Quinoqueloculina seminulum Linne, 1958 a

24. Quinoqueloculina sp. a

25. Triloculina sp. a

26. Triloculina sp. a

27. Triloculina trigonula (Lamarck, 1804) a

28. Idalina sinjarica Grimsdale, 1952 a

29. Alveolina oblonga d’Orbigny, 1826 a

30. Alveolina elliptica Sowerby, 1840 a

31. Alveolina dachelansis Schwager, 1883 a

32. Alveolina munieri Hottinger, 1960 a

33. Alveolina ovulum Stachein Schwager, 1883 a

34. Alveolina globosa Leymerie, 1846 a

35. Alveolina schwageri Checchia-Rispoli a

36. Alveolina solida Hottinger, 1960 a

37. Alveolina (Glomalveolina) levis (Hottinger, 1960) a

38. Alveolina elliptica (Sowerby) a

39. Alveolina daniensis Drobne, 1977 a

40. Alveolina ellipsoidalis Schwager, 1883 a

41. Alveolina cf. elliptica (Sowerby), a

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42. Alveolina decipiens Schwager, a

43. Alveolina cf. dainellii Hottinger, 1960 a

44. Alveolina aragonensis Hottinger, 1960 a

45. Alveolina nuttalli (Davies, 1940) a

46. Alveolina D'Orbigny, 1826, Alveolina sp. a

47. Alveolina D'Orbigny, 1826, Alveolina sp. a

48. Fasciolites elliptica Sowerby; Nuttal, 1925 a

49. Discocyclina ranikotensis Davies a

50. Discocyclina pygmae Henrici, 1934 a

51. Discocyclina archiaci Schlumberger a

52. Discocyclina javana (Verveek) 1892 a

53. Discocyclina, Gumbel, 1970, Discocyclina sp. a

54. Genus Discocyclina, Gumbel, 1970, Discocyclina sp. a



57. Pellatispira inflata Umbgrove, 1928; a

58. Pellatispira madaraszi Hantken, 1941 a

59. Pellatispira orbitoidea (Provale) a

60. Genus - Pellatispira, Boussac, 1906 a

61. Pellatispira orbitoidea (Provale), Umbgrove, 1928 a

62. Operculina patalensis Davies & Pinfold, 1937 a

63. Operculina, d’Ordigny, 1826, Operculina sp. a

64. Rotalites trochidiformis Lamarck, 1804 a

65. Lockhartia haimei Devies, Davies and Pinfold, 1937 a

66. Orbitolites complanatus Lamarck, 1801 a

67. Assilina spira Corrugate a

68. Assilina laminosa Gill, 1953 a

69. Biloculinites paleocenica Rahagi, 1983 a

70. Biloculinites Rahaghi, 1983, Biloculina sp. a

71. Biloculina murrhyna Schwager, 1866 a

72. Eponides de Montfort, 1808, Eponides sp. a

73. Orbitosiphon punjabensis (Davies) Tan, 1939 a

Checklist of the foraminifera

The recorded foraminiferal assemblage from the study area comprises 34

taxa belonging to 20 genera and 14 families and all have been recognised upto

specific level. The checklist of the taxa is as follows-

(Nummulitidae de Blainville, 1827; Miscellaneidae, Sigal, 1952;

Textulariidae Ehrenberg, 1838; Miliolidea (Hauerinidae Schwager, 1876);

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Hauerinidae Schwager, 1876; Textulariidae Ehrenberg, 1838; Alveolinidea

Ehrenberg, 1839; Nummulitidae, Galloway, 1928; Discocyclinidae Galloway, 1928;

Calcarinidae; Rotalidae Ehrenberg, 1839; Rotaliidae; Soritidae Ehrenberg 1839;

Fabulariidae Ehrenberg, 1839; Eponididae Hofker, 1951; Lepidorbitoididae

Vaughan, 1933).

1. Nummulites pengaronensis Verbeek, 1871

2. Nummulites acutus Sowerby, 1840

3. Nummulites millecaput Boubee, 1832

4. Nummulites globules Leymerie, 1846

5. Nummulites beaumonti d’Archiac and Haime 1853

6. Nummulites perforatus (de Montfort), Sengupta, 1965

7. Nummulites pratti d'Archiac and Haime, 1853

8. Nummulites mamillatus (Fichtel and Moll)

9. Nummulites preaturicus Schaub, 1962

10. Nummulites obtusus Sowerby, 1840

11. Ranikothalia nuttalli (Davies), Nagappa, 1959

12. Ranikothalia sindensis (Davies) Caudri, 1944

13. Ranikothalia sp.

14. Miscellanea sp.

15. Miscellanea juliettae Leppig, 1988

16. Miscellanea yvettae Leppig, 1988

17. Glomalveolina primaevea Reichel, 1937

18. Glomalveolina primaevea Hottinger, 1962

19. Glomalveolina levis (Hottinger, 1960)

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20. Textularia sagittula Defrance, 1824

21. Textularia barrette Jones and Parker, 1871

22. Textularia biserial de Blainville, 1824

23. Quinoqueloculina seminulum Linne, 1958

24. Quinoqueloculina sp.

25. Triloculina sp.

26. Triloculina sp.

27. Triloculina trigonula (Lamarck, 1804), d’ Orbigny, 1826

28. Idalina sinjarica Grimsdale, 1952

29. Alveolina oblonga d’Orbigny, 1826

30. Alveolina elliptica (Sowerby, 1840)

31. Alveolina dachelansis Schwager, 1883

32. Alveolina munieri Hottinger, 1960

33. Alveolina ovulum Stachein Schwager, 1883

34. Alveolina globosa Leymerie, 1846

35. Alveolina schwageri Checchia-Rispoli

36. Alveolina solida Hottinger, 1960

37. Alveolina (Glomalveolina) levis (Hottinger, 1960)

38. Alveolina elliptica (Sowerby)

39. Alveolina daniensis Drobne, 1977

40. Alveolina ellipsoidalis Schwager, 1883

41. Alveolina cf. elliptica (Sowerby),

42. Alveolina decipiens Schwager,

43. Alveolina cf. dainellii Hottinger, 1960

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44. Alveolina aragonensis Hottinger, 1960

45. Alveolina nuttalli (Davies, 1940)

46. Alveolina D'Orbigny, 1826, Alveolina sp.

47. Alveolina D'Orbigny, 1826, Alveolina sp.

48. Fasciolites elliptica Sowerby; Nuttal, 1925

49. Discocyclina ranikotensis Davies

50. Discocyclina pygmae Henrici, 1934

51. Discocyclina archiaci Schlumberger

52. Discocyclina javana (Verveek) 1892

53. Discocyclina, Gumbel, 1970, Discocyclina sp.




57. Pellatispira inflata Umbgrove, 1928

58. Pellatispira madaraszi Hantken, 1941

59. Pellatispira orbitoidea (Provale)

60. Pellatispira, Boussac, 1906, Pellatispira sp.

61. Pellatispira orbitoidea (Provale), Umbgrove, 1928

62. Operculina patalensis Davies and Pinfold, 1937

63. Operculina, d’Ordigny, 1826, Operculina sp.

64. Rotalites trochidiformis Lamarck, 1804

65. Lockhartia haimei Devies, Davies and Pinfold, 1937

66. Orbitolites complanatus Lamarck, 1801

67. Assilina spira Corrugate

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68. Assilina laminosa Gill, 1953

69. Biloculinites paleocenica Rahagi, 1983

70. Biloculinites, Rahaghi, 1983, Biloculina sp.

71. Biloculina murrhyna Schwager, 1866

72. Eponides de Montfort, 1808, Eponides sp.

73. Orbitosiphon punjabensis (Davies) Tan, 1939

5.3.3: Age range of diagnostic species

Foraminfers are widely used in stratigraphy as they were widely distributed

all over the world. Though as a whole, they have long geological distribution, some

of the genera and species have short geological distribution. That is why; they are

now useful for age determination and correlation purposes as index fossils.

Foraminifers are in many respects ideal zonal indices for marine rocks due to

their wide distribution and extremely diverse type. Many also have an intricate

morphology in which evolutionary changes can be readily traced. Planktonic

foraminifers provide the basis of important schemes for intercontinental correlation

of Mesozoic and Cenozoic rocks. Moreover, they are now widely used in Deep Sea

Stratigraphy. Benthic foraminifers tend to be more restricted in distribution but

useful scheme for local correlation.

Many workers have outlined the value of foraminifers as indicator of depth

of deposition, comparison in most of the cases being made with the depth ranges of

recent genera and species. Evidence for vertical movements in young oceanic crust

has been computed from such studies in Cenozoic rocks. Benthic depth related

assemblages are determined for Tertiary sediments. Moreover, depth related

assemblages are also recognized in Cretaceous sediments. Moreover, it is recorded

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that higher diverse assemblages are gradually found in deeper waters than in

shallower waters.

Environmental interpretations that use fossil foraminifers are found mainly

on comparisons with the numerous studies of recent ecology. Moreover,

palaeogeography, palaeosalinity and palaeotemperture are also determined with the

help of different foraminifera after studying the present forms. The narrow

temperature ranges of planktonic species have become useful tools for studying

palaeoclimatology.

For the varied scope of applications, foraminifers are ideal fossils used in

petroleum and marine coal deposits because majority of the oil and coal deposits

associated with marine rocks which bear abundant foraminifers. Foraminifers are of

considerable values in oil exploration and oil field development. They are also

useful for determination of ancient shore line, depth of basin, fluctuation of sea

level, determination of palaeotemperature and palaeosalinity etc. Besides these they

are also helpful to determine the depositional condition of the calcareous sediments.

5.3.4: Systemetic descreption of some diagnostic species

The three limestone members of the Shella Formation viz Lakadong

Limestone, Umlatdoh Limestone and Prang Limestone are moderate to highly

fossiliferous. The fossil assemblages are represented by larger and smaller (micro)

mostly benthic foraminiferas along with the calcereous algeae. Some of the

diagnostic species and their systemetic descreption are as follows-

1. Nummulites sp.

Phylum - Protozoa Von Seibold, 1845

Sub-phylum - Sarcodina, Shamards, 1871

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Class -Reticularia Lankester, 1871

Sub-class - Granuloreticularia Saedclur, 1934

Order - Foraminiferida Eichwald, 1830

Family - Nummulitidae de Blainville, 1827

Genus - Nummulites Lamarck, 1801

Distinguishing characteristics: The Megalospheric generation has an elongated

ovoid test with maximum length of 0.70mm and maximum width of 0.50mm. The

chambers are arranged bilocularly throughout ontogeny. The megalosphere and

aperture have not been observed.

Remarks: Nummulites are a large and important variety of single-celled organisms,

or 'protists'. These otherwise amoeba-like creatures build themselves elaborate shells

of calcium carbonate. These shells increase in size in a predictable way as the

creataceous age, and, being made of mineral, the shells are preserved readily as

fossils.

Type species - Nummulites pengaronensis Verbeek, 1871

Section: 7, Figure: 5.01

Nummulites pengaronensis Verbeek, 1871, p.3-6, pl.1, figs.1a-k

Nummulites pengaronensis (Vrbeek, 1871), Nagappa, 1959, pl.5, fig.3, pl. 9, figs.

Pl. 10, figs. 3-5; Samanta, 1968, p. 676-680, pl. 128, figs. 1-10; Samanta, 1988, pl.5,

fig.1; Saraswati et.al.2000, pl.4, figs. 9-16; Govindan, 2003, pl.3 figs 1a-b.

Remarks: The specimens are referable to Nummulites pengaronensis Verbeek

(1871).

Horizon: Prang Limestone, Shella formation, Jaiantia Group.

Locality: From near Shella Bazar, East khasi Hills District, Meghalaya, India

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Stratigraphic range (Age): Middle Eocene to Upper Eocene

Genus - Nummulites, Lamarck, 1801

Type species - Nummulites acutus Sowerby, 1840

Nummulites acutus Sowerby; Nuttal, 1926, Geol, Surv. Rec. vol. 59, pp. 115-164, pl.

2, figs. 1-4

Section: 4, Figure: 5.02 and 5.03

Distinguishing characteristics: Megalospheric, forms are abundantly recorded from

the study area. The megalospheric forms are highly biconvex with centrally raised

mamelon which is covered by strong pustules. The margins of the shells are very

sharp. The initial chambers of the tests are large and nearly circular. The number of

whorls is 5-7 and the coiling is + regular in equatorial sections. Septa are thin.The

diameter of the tests varies from 2.1mm to 3.5mm and the thickness from 1.4mm to

2.1mm. However, a maximum diameter of 4.4mm and a maximum thickness of

2.6mm are recorded from the study area.

Remarks: This species is reported from Kutch and Cambay basin (Pandey, 1972)

and also from Jaisalmer basin (Singh, 1983).

Horizon: Prang Limestone and Umlatdoh Limestone, Shella formation, Jaintia

Group.

Locality: Shella and Ishamati area, East khasi Hills District, Meghalaya, India

Stratigraphic range (Age): Upper Eocene


Type species - Nummulites millecaput Boubee, 1832

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Distinguishing characteristics: The megalospheric forms are highly biconvex with

centrally raised mamelon, which is covered by strong pustules. The margins of the

shells are very sharp. The initial chambers of the tests are large and nearly circular.

The values for the thickness of the shell, the diameter of the initial chamber, and the

ratio of the diameter of the third whorl to the diameter of the initial chamber are

normally distributed around the mean. The thickness of the spiral layer increases to

the third whorl, then decreases. The diameter of the initial chamber correlates with

the diameter rather than the thickness of the shell.

Remarks: Foraminifera are generally microscopic, but Nummulites millecaput,

which lived in the Eocene epoch around 50 million years ago, during the warmest

climatic episode since before the demise of the dinosaurs, grew to 160 mm in

diameter. After this acme, nummulites declined in size and diversity, and their living

relatives seldom exceed 2 mm in size or live longer than a year or two. These are

disc-shaped, single-celled organisms called nummulites, some of which were as big

as coasters and could have lived for more than a century - certainly the biggest, and

arguably the longest-lived, of all known single-celled creatures (Henry, 1999)

Horizon: Prang Limestone and Umlatdoh Limestone, Shella formation, Jaintia

Group.


Stratigraphic range (Age): Middle Eocene to Upper Eocene.


Type species - Nummulites globules Leymerie, 1846

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Nummulites globulus Leymerie, 1846; p.359, pl. XIII, figs. 14a, 14 d


Distinguishing characteristics: Megalospheric, forms are highly biconvex with

centrally raised mamelon, which is covered by strong pustules. The margins of the

shells are very sharp. The initial chambers of the tests are large and nearly circular.

The number of whorls is 4-5 and the coiling is + regular in equatorial sections. Septa

are thin.The diameter of the tests varies from 2.0mm to 3.5mm and the thickness

from 1.5 mm to 2.0 mm.

Remarks: This genus is reported from Upper Eocene rocks of Kutch and Cambay

basin (Pandey, 1972) and from Jaisalmer basin (Singh, 1983).

Horizon: Umlatdoh Limestone, Shella formation, Jaintia Group.


Stratigraphic range (Age): Upper Eocene


Type species - Nummulites beaumonti d’Archiac and Haime 1853

Nummulites beaumonti d’Archiac and Haime, 1853, p.133, pl.8 figs. la-e 2, 3

Nummulites beaumonti (d’Archiac and Haime), Davies, 1940, p 206-209,pl.ix,

figs.1-9, Nagappa, 1959,pl.5,fig.2,pl.8,figs.15,17, pl.9, figs.12; Sengupta, 1965,

pl.15,figs.1,2 &5, pl.16, figs.3,7,9,10, pl.17,figs.1,5,7,12; Govindan, 2003,

pl.2,figs.2a-b.


Distinguishing characteristics: Test lenticular to biconical, the marginal cord is

distinct and pillars increase in thickness at the polar region forming axial plug.

136

Remarks: The morphological character of the species is more akin to Nummulites

beaumonti. Sengupta, 1965 treated this species as synonemous to Nummulites

pengaronensis. However, Saraswati et. al. (2000) suggested that Nummulites

pengaronensis is a morphologically distinct species.





Type species - Nummulites perforatus (de Montfort), Sengupta, 1965,

Nummulites perforatus (de Montfort),

Sengupta, 1965, pl.16, figs.1, 2 and 11, pl.17, figs.3, 9, 10, 13; Samanta, 1981, ap.

818, pl.16, figs.1-2; Govindan, 2003, pl.3, figs. 2a-b.

Section: 4 and 5, Figure: 5.07 and 5.12

Distinguishing characteristics: Test lenticular or flat disc shaped, often saddle-

shaped or with undulating border, edge sharp. Surface with strongly curved or

meandriform raised lines, joining in one or more points, often not very clear or

lacking.

Remarks: The morphological character of the species is more akin to Nummulites

perforatus. Sengupta (1965) treated this species as synonemous to Nummulites

perforatus. However, Samanta, 1981 suggested that Nummulites perforatus is a

morphologically distinct species with Nummulites perforatus of de Montfort.

Horizon: Umlatdoh Limestone and Prang Limestone, Shella formation, Jaintia

Group.


137


Genus Nummulites, Lamarck, 1801

Type species Nummulites pratti d'Archiac and Haime, 1853;

Nummulites pratti d'Archiac and Haime, 1853;

Nummulites pratti (d'Archiac and Haime) Schaub (1981), Pl. 65, Figs. 32-53.

Section: 4 and 5, Figure: 5.08

Distinguishing characteristics: Test lenticular to biconical. The marginal cord is

distinct and pillars increase in thickness at the polar region forming axial plug, edge

sharp, surface with strongly curved or meandriform raised lines.

Remarks: Schaub (1981), several specimens to this species that displayed a large

proloculus (0.5 mm) and a growth rate similar to that of N. pratti. The specimen

illustrated in Figure 5.07, is a characteristic axial section of N. pratti.


Group.




Type species - Nummulites mamillatus (Fichtel and Moll);

Nummulites mamillatus Fichtel and Moll, 1798

Nummulites mammillatus (Fichtel and Moll), Nuttal, 1925, p. 445, pl. 27, figs. 1-3.


138

Distinguishing characteristics: Test lenticular to biconical. The marginal cord is

distinct, thick wall, narrowly spaced chambers and the presence of umbonal pillars

as seen in the vertical view. The specimen is strongly biconvex.

Remarks: This species is very common and abundant in Middle Eocene Kohat

Formation, Shekhan Nala, Kohat Basin, and Northern Pakistan. It is characterize by

having a biconvex shell with thick umbilical pillars in the middle part. Marginal

cord is present, but comparatively thin as compared to the other species of

Nummulites (Mirza, et. al. 2005).


Group.




Type species - Nummulites preaturicus Schaub, 1962

Nummulites preaturicus Schaub, 1962, A Form. P1. 28, figs 6-7


Distinguishing characteristics: Test lenticular or flat disc shaped or with undulating

border, edge sharp. Surface with strongly curved or meandriform raised lines,

joining in one or more points, often not very clear or lacking.

Remarks: The morphological character of the species is more akin to N. preaturicus.

Schaub (1962) treated this species as synonemous to Nummulites preaturicus.

Horizon: Prang Limestone, Shella formation, Jaintia Group.


139



Type species - Nummulites obtusus Sowerby, 1840

Nummulites obtusus Sowerby, 1840, p.329, pl. 24, fig. 14

Nummulites obtusus (Sowerby), 1840; Schaub, 1981, p 106; table 3, fig. g ;

Samanta, 1981a, p 804; pl 113, figs. 3-5; pl 114, pl 115; Samanta et.al., 1990, p 37-

38; pl 8, figs. 1-4; pl 9, figs.1, 3-10, pl 10, figs. 19-28, pl. 11, figs. 6-9; Racey,

1995, p. 55-56, pl. 3, figs. 8-10


Distinguishing characteristics: Megalospheric form, test inflated, lenticular or flat

disc shaped, with a broadly rounded mergin, septal filaments sinuous to

meandriform, fine granuls attached to some septal filament; edge sharp.

Remarks: The morphological character of the species is more akin to N. obtusus

(Sowerby, 1840).Sengupta (1965) treated this species as synonemous to N.

perforatus from the Harudi Formation. Samanta (1981a) has shown that although

this species has been reported from different parts of Tethyan regions, the only

verifiable records from Kutch in India and the adjoining Sind areas of Pakistan.

Racey (1995) reported it from Oman.




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2. Ranikothalia sp.


Suborder - Rotalina Delage and Herourd, 1896

Superfamily - Nummulitacea de Blainville, 1827


Genus - Ranikothalia Caudri, 1944

Type Species - Ranikothalia nuttalli (Davies) Nagappa, 1959

Ranikothalia nuttalli (Davies) Nagappa, 1959, pl.3, fig.3;

Ranikothalia nuttalli (Davies) Samanta, 1988, pl.1, fig.1-2, pl.8, figs. 5 & 11, 12.


Distinguishing characteristics: The test elongated, lenticular with central boss.

Megalospheric form with bilocular embryo 9.4-6.0mm in diameter. Chambers have

very long prolongations.

Remarks: The diagnostic characters are more akin to Ranikothalia nuttalli Davies,

which is a very common form present in the Paleocene outcrops of India.

Horizon: Lakadong Limestone, Shella formation, Jaintia Group.

Locality: Near Mawlong, East khasi Hills District, Meghalaya, India

Stratigraphic range (Age): Middle Paleocene to Upper Paleocene

Type Species - Ranikothalia sindensis (Davies) Caudri, 1944

Operculina sindensis Davies, 1927, p. 274, pl. 19, figs. 10-13.

Nummulites sindensis (Davies), 1937, Davies and Pinfold, p. 21, pl. 4, fig. 21.

Nummulitoides sindensis (Davies), 1967, Barut, Bouroullec and Villatte, p. 384, pl.

1-3.

141

Ranikothalia bermudezi (Palmer), 1969, Butterlin and Monod, p. 595, pl. 2, fig. 1-2.

Ranikothalia sindensis (Davies), 1969, Butterlin and Monod, pl. 2, fig. 4.

Ranikothalia sindensis (Davies), 1977, Hottinger, p. 50, pl. 16, figs. 1-5.

Ranikothalia sindensis (Davies), 1983, Sirel, Gunduz and Acar, p. 151, pl. 3, figs. 8-

10.

Ranikothalia sindensis (Davies), 1991, Butt, p. 77, pls. 1-4.


Distinguishing characteristics: The test compressed and involute. The axial section

showing very long, thin alar prolongations but continue to umbilicus. Wall

calcareous and structure is not coarsely perforate except at the marginal cord.

Marginal cords thick, swollen and coarsely perforat. The length of the test is 6.1 mm

and breath measure is 0.98 mm to 0.32 mm. The umbilical portions have a thickness

of 0.66 mm. Inner length of the initial chamber 0.30 mm and with 0.10 mm.

Remarks: The majority of specimens of Ranikothalia sindensis are flattened and

almost identical to the figured specimens of Butt (1991) and Sirel (1998). The base

of the Ranikothalia sindensis Zone corresponds to the first stratigraphic appearance

of Idalina sinjarica Grimsdale, Fallotella alavensis Mangin in the commonly

occurring Palaeocene assemblage of Miscellanea miscella (D’Archiac and Haime),

and Haymanella paleocenica Sirel. The succeeding Zone is marked with the entry of

Assilina laminose Gill, Discocyclina dispansa Sowerby and associated with

Opertorbitolites douvillei (Nuttall), Alveolina pasticillata Schwager in Early Eocene

(Babazadeh, 2011).



142

Stratigraphic range (Age): Middle Paleocene to Upper Paleocene


Genus - Ranikothalia Caudri, 1944

Ranikothalia sp.


Distinguishing characteristics: The test compressed and involute. The axial section

showing long, thin alar prolongations (comparatively thicker than Ranikothalia

sindensis), but continue to umbilicus. Wall calcareous and structure is not coarsely

perforate except at the marginal cord. Marginal cords thick and perforate. Proloculus

not seen. Length of the specimen is 3.1 mm and width 0.70 mm.

Remarks: The majority of specimens of Ranikothalia sp. are flattened and almost

identical to the figured specimens of Butt (1991) and Sirel (1998). The genus

Ranikothalia Caudri, 1944 was recorded from Late Paleocene rocks and showing a

similar stratigraphic distribution in Middle East. It is reported for the first time from

Lower Eocene platform limestones in eastern Iran (Babazadeh, 2011).



Stratigraphic range (Age): Late Paleocene to Early Eocene

Superfamily - Nummulitacea de Blainville, 1827

Family - Miscellaneidae, Sigal, 1952

Genus - Miscellanea, Pfender, 1934

Type species - Miscellanea sp.

143

Miscellanea miscella D’Archiac and Haime, 1853

Nummulites miscella D’Archiac and Haime, 1853, 1853, p. 345, Pl. 35, figs. 4a-c.

Siderolites miscella (D’Archiac and Haime) Douville, 1916, p. 38, Pl. 15.

Miscellanea miscella (d’Archiac and Haime), Pefender, 1935, p.231, pl.11, figs.6, 7,

pl.13, figs. 2-4; Davies and Pinfold, 1937, p.43, pl.4, figs.1-3, 7-8.

Miscellanea miscella (d’Archiac and Haime), Nagappa, 1959, p.3, pl.4, figs.1;

Samanta, 1988, pl.1, figs.2, pl. 8.figs.6, 8, 9 and 13; Jauhri, 1998, pl.1, figs.2-3, pl.2,

figs.9,11; Govindan, 2003.pl.4, figs.16a-b.


Distinguishing characteristics: The form is globular and lenticular in shape. Both

microspheric and megalospheric forms are much more abundant and they are

elongated. Marginal chord is not observed in the forms. The coiling is involute. The

spire interval enlarges slightly and gradually throughout the coiling. The shapes of

the chambers are irregular, mostly their tops are rounded and their heights are

always more than their widths. The numbers of whorls are usually three but

sometimes an incomplete outer whorl is also observed.

Remarks: The form is recorded from the Late Paleocene of Ranikot, Punjab Salt

Range and Lakadong Limestone of Khasi and Jaintia Hills, Meghalaya.



Stratigraphic range (Age): Late Paleocene.

Type species - Miscellanea juliettae Leppig, 1988


144

Distinguishing characteristics: both megalospheric (A-form) and microspheric (B-

form) forms represent this species. The megalospheric equatorial section observed in

thin sections of the sample shows invaginated body whorl. Diameter of the test is

1.20 mm and size of the proloculus is 0.16 mm. Number of body whorl is 2. Sixteen

and eleven chambers are observed in the last whorl and first whorl respectively.The

megalospheric axial sections are observed in thin sections of the sample. The form is

strongly biconvex and involute. Strong ornamental pillars are confined to the

umbilical area. Diameter of the proloculus is 0.10 mm. Length, breath of the test is

1.40 mm, and 0.90 mm respectively.The microspheric equatorial sections are

observed in the thin sections of the sample. Diameter of the test is 1.50 mm and 3.5

numbers of whorls are observed.The microspheric axial section observed in thin

sections of the sample are characterised by strongly invaginated peripheral margin.

The length and breath measured in the form is 1.70 mm and 0.90 mm respectively.

The ornamental pillars are confined to the umbilical area.

Remarks: The form is recorded from the Late Paleocene of Ranikot, Punjab Salt

Range and Lakadong Limestone of Khasi and Jaintia Hills, Meghalaya.




Type species Miscellanea yvettae Leppig, 1988


Distinguishing characteristics: The megalospheric equatorial sections of the

specimens observed in the sample shows in vaginate peripheral margin. The

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diameter of the test is 1.1 mm and proloculus is 0.15 mm. Length of the test is 1.40

mm and breath of the test is 0.90 mm. Microspheric axial section of the specimen is

observed in the thin sections of the sample, the length of the test is 1.50 mm and

breath is 0.70 mm. Size of the proloculus is 0.03 mm.

Remarks: Miscellanea yvettae in Lakadong Limestone is represented by both

megalospheric (A-form) and microspheric (B-form) specimen. The specimen is

occurring less commonly then the other two specimens of Miscellanea viz. M.

juliettae and M. miscella.


Locality: Near Mawlong, East khasi Hills District, Meghalaya, India.


4. Glomalveolina sp.


Family - Alveolinidae Ehrenberg, 1839

Genus - Glomalveolina Reichel, 1937

Type Species - Glomalveolina primaevea Reichel, 1937

Glomalveolina primaeva (Reichel, 1936); Pl. 5, fig. 5; Pl. 7, Figs. 7b, 8a–b


Glomalveolina primaevea Hottinger, 1962


Distinguishing characteristics: Test circular (Fig 5.82 and Fig 5.83) to ovoidal (Fig

5.84) with both micro and megalospheric forms; equatorial diameter of the species is

1.5 mm. Proloculus circular and has an internal diameter of 0.06 mm. The chambers

are small and subcircular. There are six whorls at a radius of 1.5 mm.

146

Remarks: Scheibner and Speijer, 2009 investigated the Galala Mountains in Egypt

provides an excellent platform-basin transect with deposits spanning the

Paleocene/Eocene boundary. The Late Palaeocene to Early Eocene development of

larger foraminifera is well recorded in the Galala transect, in particular the Tethyan

evolutionary event known as the larger foraminifera turnover (LFT). This turnover

distinguishes Paleocene assemblages dominated by glomalveolinids, miscellanids

and ranikothalids typical for shallow benthic Zone 4 (SBZ4) from those of SBZ5,

dominated by alveolinids, nummulitids, and orbitolitids. Prior to the revision of the

shallow-benthic foraminiferal biozonation (Serra-Kiel et al., 1998) SBZ3 was

established by Hottinger (1960) as the G. primaeva Biozone, defined by the total

range of Glomalveolina primaeva.


Locality: Near Mawlong, East Khasi Hills District, Meghalaya, India

Stratigraphic range (Age): Middle Paleocene

Type Species - Glomalveolina levis (Hottinger, 1960)


Distinguishing characteristics: The test elliptical, diameter 2.06mm x 1.68 mm.

There are seven (7) whorls observed in the specimen. The whorls are elliptical in

outline and wall thick (0.06 mm), septa 0.04 mm thick. Chambers are small and

subspherical in the inner whorls and they are large or subquadrangular in the last

whorls. Proloculus not seen.

Remarks: The Tethyan evolutionary event known as the larger foraminiferal

turnover (LFT) is distinguishes Paleocene assemblages dominated by

147

glomalveolinids, miscellanids and ranikothalids typical for shallow benthic Zone 4

(SBZ4) of Serra-Kiel et. al. (1998)



Stratigraphic range (Age): Middle Paleocene.

5. Textularia sp.


Suborder - Textularina Delage and H’erouard, 1896

Superfamily - Textulariacea Ehrenberg, 1838

Family - Textulariidae Ehrenberg, 1838

Subfamily - Textulariinae Ehrenberg, 1838

Genus - Textularia Defrance, 1824

Type species - Textularia sagittula Defrance, 1824

Textularia sagittula Defrance, 1824; p. 177

Textularia sagittula Defrance, 1824 in de Blainville, 1824

Textularia sagittula Defrance; Jorissen, 1987, p. 41, pl. 3, fig. 12

Textularia sagittula Defrance; Rasmussen, 2005, p. 57, pl. 2, fig. 3


Distinguishing characteristics: Test biserial, wedge shaped, two longitudinal rows of

chambers separated by irregular median suture, aperture terminal, chambers are

simple with acute spiral angle.

Remarks: Defrance (1824) reported Textularia sagittula species from Paleocene

rocks of Castel-Arquato, Italy. Mojtahid et. al. (2006) reported Textularia sagittula

148

as bio-indicators of drill cutting disposal in tropical east Atlantic outer shelf

environments of Congo, West Africa.



Stratigraphic range (Age): Paleocene to Upper Eocene

Genus - Textularia, Defrance, 1824

Type species - Textularia barretti Jones and Parker, 1871


Distinguishing characteristics: Test elongate, leaf or wedge shaped, tapering, early

chambers planispirally coiled, rapidly becoming biserial, chambers simple, not

labyrinthic. The measured length of the specimen observed in axial section is 1.0-

1.05 mm and breadth is 0.60-0.70 mm at the end of the test.

Remarks: Gogoi et. al. (2009) reported Textularia barretti from Lakadong

Limestone (Palaeocene) of the Mawsynram area, south Shillong Platue, Meghalaya,

India




Genus - Textularia Defrance, 1824

Type species - Textularia biserial, de Blainville, 1824


149

Distinguishing characteristics: Test biserial, wedge shaped, two longitudinal rows of

chambers separated by irregular median suture, aperture terminal, chambers are

simple with acute spiral angle.

Remarks: Gogoi et. al. (2009) reported Textularia biserial from Lakadong

Limestone of the Mawsynram area, south Shillong Platue, Meghalaya, India




6. Quinoqueloculina sp.

Order – Foraminiferida Eichwald, 1830

Suborder – Miliolina, Delange and Herouard, 1896

Superfamily - Miliolacea, Ehrenberg, 1839

Family – Hauerinidae, Schwager, 1876

Subfamily - Siphonapertinae Saidova, 1975

Genus - Quinoqueloculina, d’Orbigny, 1826

Type Species - Quinoqueloculina seminulum Linne, 1958


Distinguishing characteristics: Test coiled along an elongated axis; spindle shaped in

side view chambers visible. The angular relation between adjacent chambers is 720

Chambers tube shaped, larger ones covering the smaller ones. Margins entire,

chambers increasing outwards from the center, aperture terminal, and circular with

one tooth.

150

Remarks: Gogoi et. al., (2009) reported Quinqueloculina seminulum from Lakadong

Limestone of the Mawsynram area, south Shillong Plateau, Meghalaya, India. In the

Gulf of Mexico the Miliolidae are abundant at depths of 30 m (Shifflett, 1961), 70-

100m (the genus Quinqueloculina chiefly in the inner turbulent zone at 20-30 m;

Phleger, 1960), or even down to 150 m (Parker, 1954), and do not descend below

180-220m (Phleger and Parker, 1951).




Genus - Quinoqueloculina, d’Orbigny, 1826

Quinoqueloculina sp.


Distinguishing characteristics: Test coiled along an elongated axis; spindle shaped in

side view chambers visible. The angular relation between adjacent chambers is 720

Chambers tube shaped, larger ones covering the smaller ones. Margins entire,

chambers increasing outwards from the center, aperture terminal, and circular with

one tooth.

Remarks: Gogoi et. al. (2009) reported Quinqueloculina seminulum (Linne 1958)

from Lakadong Limestone of the Mawsynram area, south Shillong Platue,

Meghalaya, India




151

7. Triloculina sp.

Order – Foraminiferida Eichwald, 1830

Family – Miliolidea d’ Orbigny, 1839

Subfamily - Miliolinellinae Vella, 1957

Genus - Triloculina d’ Orbigny, 1826

Triloculina sp.


Distinguishing characteristics: Chambers elongated, coiled about the transverse axis

with two chambers in each coil. Later chambers placed on radial planes, 1200 apart,

three chambers taking part in the formation of outer surface of the test, chambers

half a coil in length, wall smooth, aperture round.

Remarks: The Miliolidae are a foraminiferal group having small requirements in

respect of water salinity, for they may be found in both salt and brackish waters, but

their occurrence is frequently restricted to only certain depths and temperatures. In

the contemporary seas they prevail over inner shelf and in open gulfs, in warm and

shallow tropical and subtropical waters, at depths from zero to about 100 m (Sigal,

1952), where they may form 50 per cent or more of the whole population. They

belong chiefly to different species of Quinqueloculina and Triloculina, which are

good indicators of conditions in the vinicity of coasts. The pattern of distribution of

the Miliolidae is only reported from tropical regions, large numbers of miliolids are

a reliable indication of very shallow regions of warm water all over the world.

Horizon: Lakadong Limestone, Shella Formation, Jaintia Group.



152

Genus – Triloculina, d’Ordigny, 1826

Triloculina sp.


Distinguishing characteristics: Test free, early chambers quinqueloculine, chambers

elongated, the inner thickness of the adult chamber are ranging from 0.05µm to 0.07

µm which coiled from end to end about a revolving elongate axis, 120o apart, every

thired one superimposed, three chambers visible, wall smooth, aperture round.

Remarks: The pattern of distribution of the Triloculina is generally noted in tropical

regions, shallow regions of warm marine environment.




Genus - Triloculina d’ Orbigny, 1826

Type species - Triloculina trigonula (Lamarck, 1804), d’ Orbigny, 1826

Triloculina trigonula Lamarck, 1804, p. 351; vol. 9, 1807, pl. 17, fig 4

Triloculina trigonula (Lamarck), d’ Orbigny, 1826, vol. 7, p. 229, pl. 16, figs 5-9

Triloculina trigonula (Lamarck), Schlumberger, 1893, vol. 6, p. 62,

Triloculina trigonula (Lamarck), Cushman, 1917, Bull. 71, pt. 6, p. 65


Distinguishing characteristics: Test free, chambers elongated, the inner thickness of

the adult chamber are ranging from 0.03µm to 0.05 µm that coiled from end to end

about a revolving elongate axis, 120o apart, every thired one superimposed, three

153

chambers visible, wall smooth, aperture round and big in size. Test wall smooth,

thickness reaches up to 0.05 mm.

Remarks: The pattern of distribution of the Triloculina trigonula is generally noted

in tropical regions, shallow regions of warm marine environment.



Stratigraphic range (Age): Middle Eocene

8. Idalina sp.


Family – Hauerinidae Schwager, 1876

Genus – Idalina Munier Chalmas and Schlumberger, 1884

Type Species - Idalina sinjarica Grimsdale, 1952

Idalina sinjarica Grimsdale, 1952, Vol. 1, p. 230, plate 20, Figs. 11-14

Idalina sinjarica Grimsdale, Babazadeh, 2011, Vol. 30 (1), p. 313-319, Fig.3-1

Section: 2 and 3, Figures: 5.58

Distinguishing characteristics: The Megalospheric generation has an elongated

ovoid test with maximum length of 0.70 mm and maximum width of 0.50 mm. The

chambers are arranged bilocularly throughout ontogeny. The megalosphere and

aperture have not been observed.

Remarks: Gogoi et. al. (2009) reported genus-Idalina Munier Chalmas and

Schlumberger, 1884, Idalina sp. from Lakadong Limestone of the Mawsynram area,

south Shillong Platue, Meghalaya, India. Idalina sinjarica – Miscellanea miscella –

Lockhartia haimei assemblage may be at least correlatable with “Shallow benthic

154

zones” SBZ3 to SBZ4 by Serra-Kiel et. al., (1998) from the common range of

Idalina sinjarica, Miscellanea primitiva, and Miscellanea miscella, and with the

fauna of the Thanesian Limestone of Dolenja Vas, NW Dinarides (Drobne et. al.

1988) due to the common occurrence of Idalina sinjarica and Kathina selveri.

Further, the present Assemblage in the Lakadong Limestone can partial be

correlated with the basal Larger Foraminiferal Assemblage (LFA1) i.e., Miscellanea

miscella and Ranikothalia nuttalli, in Indian Bassin as Lower Tertiary (Upper

Paleocene, Thanetian) of Letter Stages by Govindan (2003).


Locality: Near Mawlong, East Khasi Hills District of Meghalaya, India.

Stratigraphic range (Age): Upper Paleocene

9. Alveolina sp.


Suborder - Miliolina Delage and Herouard, 1896

Superfamily - Miliolacea Ehrenberg 1839

Family - Alveolinidea Ehrenberg, 1839

Genus - Alveolina D'Orbigny, 1826

Type species - Alveolina oblonga d’Orbigny, 1826

Alveolina oblonga d’Orbigny, 1826; Parkinson’s figured specimen, 1420, pl.10, figs

28-31

Alveolina oblonga d'Orbigny, 1826; Tableau methodique, Ann, Sci, Nat. Paris, Ser.

1, Vol. 7, p.306.

Alveolina oblonga d'Orbigny, Hottinger, 1960; p.141, pl. 9, figs. 4-16.

155


Distinguishing characteristics: The test is elliptical. In transverse section, the whorls

are very much close to each other and there are 12-15 whorls along the shorter axis.

The form is megalospheric and the initial chamber is sub circular to oval. Septula

alternating is adjacent chambers.

Remarks: Species of Alveolina are abundant in moderate energy shallow water

environmental conditions with significant movement and reworking of bio-clasts.

Matsumaru (1999) identifies microspheric individuals of Alveolina

oblonga d'ORBIGNY from the Lower Eocene (Cuisian) Çayraz Formation in the

Haymana area, southwest of Ankara, Turkey. These foraminifers have a large

number of megalospheric individuals near the periphery of the test, which are

megalospheric embryos fossilized in the process of multiple fission of the

microspheric agamont. Sarma (2005) also identifies this type species from the

Umlatdoh Limestone of Lower tertiary (Late Lower Eocene to Early Middle

Eocene) sequeance in South Jaintia Hills District of Meghalaya, India. A. oblonga, is

originally described from the Lower Eocene of the Paris basin; it is also reported

from the Lower Eocene of France, Italy, Spain and Egypt.


Locality: Near Ishamati, East Khasi Hills District of Meghalaya, India.

Stratigraphic range (Age): Late Lower Eocene to Early Middle Eocene


Type Species - Alveolina elliptica (Sowerby, 1840)

http://www.sciencedirect.com/science/article/pii/S0035159899900247

156

Fascoilites elliptica Sowerby, 1840, Trans.Geol. Soc. London, Ser.2, Vol.5, p. 329,

pl.18, figs. 17-17a.

Alveolina elliptica (Sowerby), 1925, Nuttall, p.378, pl. 20, figs. 1.

Alveolina elliptica (Sowerby), 1960, Hottinger, p.146, pl. 121, figs. 1-3.

Alveolina elliptica (Sowerby), 1974, Al- Hashimi, p.54, pl. 1, figs. 2-3.


Distinguishing characteristics: The test ovoidal and cylindrical with bluntly rounded

ends, imperforate, size relatively large attaining (5.0-6.5 mm) in length and (2.5-3

mm) in diameter, length /diameter average ratio is 2:1.In transverse section, the

whorls are very much close to each other and there are 6-8 whorls along the shorter

axis. The form is megalospheric but megalosphere is small, and the initial chamber

is sub circular to oval.

Remarks: Sowerby described Alveolina elliptica species originally from Cutch in

India. It has also reported from Middle Eocene Naoprdan Shally Group of northeast

Iraq. Al-Hashimi and Amer, (1985), described it from the Middle Eocene in the

middle part of the Geli Duhok section, northeastern Iraq. In the present study,

Alveolina elliptica is common in the former Qulqula Conglomerate Formation of the

Middle Eocene age.





Type species - Alveolina dachelansis Schwager, 1883

157

Alveolina dachelansis Schwager, 1883


Distinguishing characteristics: The test is ovoidal. In transverse section, the whorls




Remarks: Sarma (2005) also identifies this type genus (Alveolina oblonga) from the

Umlatdoh Limestone of Lower tertiary (Lower Eocene to Middle Eocene) sequeance

in South Jaintia Hills District of Meghalaya, India.


Locality: Near Ishamati, East Khasi Hills District, Meghalaya, India

Stratigraphic range (Age): Lower Eocene to Middle Eocene.


Type Species - Alveolina munieri Hottinger, 1960

Alveolina munieri Hottinger, 1960; p.165, pl. 16, figs. 16-21, pl. 17, figs.1-4, pl.18,

figs.1-4, 18.


Distinguishing characteristics: Test is elongate to cylindrical, with rounded to

subrounded ends, wall porcellaneous, imperforate, size relatively large attaining

(4.5-6mm) in length and (1.0-2.0mm) in diameter, length / diameter average ratio is

4:1, whorl 12-18 in numbers, tightly coiled, basal wall thin equatorially and

thickness towards the poles, chamberlets are numerous and small, supplementary

chamberlets exists in adult whorls, megalospheric is small and elongate.

158

Remarks: Alveolina munieri is originally described by Hottinger, (1960) from the

Middle Eocene of north Italy. Al-Hashimi and Amer, (1985), reported this species

from the Middle Eocene in the Avanah Formation of Geli Dohuk, northern Iraq.

Abawi and Sharbazeri, (1987) reported this species as a rare to common in the

middle and upper part of Geli Bessri section and in the middle part of Geli Dohuk

section (Middle Eocene), northern Iraq.





Type Species - Alveolina ovulum Stachein Schwager, 1883

Alveolina cf. ovulum Stachein Schwager, 1883, p.95, pl. 24, fig. 13-a-c.


Distinguishing characteristics: Test is ovate to elongate cylindrical, with rounded to

subrounded ends, wall porcellaneous, imperforate, size relatively large attaining

(3.5-4mm) in length and (1.2-1.8mm) in diameter, length / diameter average ratio is

2.2:1, whorl 7-12 in numbers,chamberlets numerous and in a single layer (6-11) per

mm in the last whorl, megalosphere is oval.

Remarks: Schwager, 1883 from the Middle Eocene of north Italy, originally

describes Alveolina ovulum, and also reported from Upper Paleocene of the Former

Qulqula Conglomerate Formation, Kurdistan Region, and Northeastern Iraq

Horizon: Umlatdoh Limestone, Shella formation, Jaintia Group


159



Type Species - Alveolina globosa Leymerie, 1846

Alveolina globosa Leymerie, 1846; p.337-373, pl. 13


Distinguishing characteristics: Test is elliptical to cylindrical, wall porcellaneous,

imperforate, size relatively large attaining (5-6.0mm) in length and (3-3.5mm) in

diameter, length / diameter ratio is about 2:1, whorl 5-7 in numbers, chamberlets are

numerous in the last whorl, megalosphere is small.

Remarks: Al-Hashimi and Amer, (1985), described A. globosa in Sinjar Formation,

northern Iraq, of Upper Paleocene. In the present study, A. globosa is common in the

Upper Paleocene carbonate rocks of the Shella Formation of Jaintia group.



Stratigraphic range (Age): Upper Paleocene


Type Species - Alveolina schwageri Checchia-Rispoli

Alveolina schwageri Checchia-Rispoli




160



Remarks: Erdem et.al, 2007, documented the claystone-limestone succession of

Ilerdian-Cuisian limestones of Southern Eskişehir, Central Turkey, 28 species

of Alveolinad’Orbigny are described and their comparative stratigraphic distribution

with the Alveolina species in the Tethyan Eocene. The the Early Middle Cuisian unit

of the Ilerdian-Cuisian limestones of Southern Eskişehir, Central Turkey, is

represented by G. minutula, A. oblonga, A. schwageri, A. haymanensis, A.

canavarii, A. aff.coudurensis, A. ruetimeyeri, A. muscatensis, A. cremae, A.

bayburtensis and A. lehneri.



Stratigraphic range (Age): Lower Eocene to Early Middle Eocene


Type Species - Alveolina solida Hottinger, 1960






Remarks: Erdem et. al. (2007) documented the claystone-limestone succession of

Ilerdian-Cuisian limestones of Southern Eskişehir, Central Turkey, 28 species

of Alveolinad’Orbigny are described and their comparative stratigraphic distribution

161

with the Alveolina species in the Tethyan Eocene. The the Early Middle Cuisian unit

of the Ilerdian-Cuisian limestones of Southern Eskişehir, Central Turkey, is

represented by G. minutula, A. oblonga, A. schwageri, A. haymanensis, A.

canavarii, A. aff. coudurensis, A. ruetimeyeri, A. muscatensis, A. cremae, A.

bayburtensis and A. lehneri.


Locality: Near Shella, East Khasi Hills District, Meghalaya, India

Stratigraphic range (Age): Lower Eocene to Early Middle Eocene

Type Species - Alveolina (Glomalveolina) levis

Alveolina (Glomalveolina) levis (Hottinger, 1960)


Distinguishing characteristics: The test is elliptical, diameter 2.06 X 1.68 mm. There

are 8 whorls observed in the specimen. The whorls are elliptical in outline and wall

thick (0.06 mm), septa 0.04 mm thick. Chambers are small and subspherical in the

inner whorls and they are large or subquadrangular in the last whorls. Proloculus not

seen.

Remarks: The Tethyan evolutionary event known as the larger foraminifera turnover

(LFT) is distinguishes Paleocene assemblages dominated by glomalveolinids,

miscellanids and ranikothalids typical for shallow benthic Zone 4 (SBZ4) of Serra-

Kiel et al., 1998.



Stratigraphic range (Age): Middle Paleocene

162


Type Species - Alveolina elliptica (Sowerby)

Alveolina elliptica (Sowerby) var. flosculina Silvestri. Smout A. H., 1954, p. 82,

pl.14, figs.8-12.

Fascoilites elliptica Sowerby, 1840, Trans. Geol. Soc. London, Ser.2, Vol.5, pp.329,

pl.18, figs. 17-17a.

Alveolina elliptica (Sowerby), 1925, Nuttall, p.378, pl. 20, figs. 1.

Alveolina elliptica (Sowerby), 1960, Hottinger, p.146, pl. 121, figs. 1-3.

Alveolina elliptica (Sowerby), 1974, Al- Hashimi, p.54, pl. 1, figs. 2-3.


Distinguishing characteristics: The test elliptical with bluntly rounded ends, wall

porcellaneous, imperforate, size relatively large attaining (4.7-6.5mm) in length and

(2.5-3mm) in diameter, length / diameter 3average ratio is 2:1, whorl 9-15 in number

along the shorter axis, in transverse section, the whorls are very much close to each

other. The form is megalospheric and the initial chamber is sub circular to oval.

Septula alternating is adjacent chambers.

Remarks: Sowerby described this species originally from Cutch in India. It is

reported from the Middle Eocene Chabd beds of southwest Iraq and from Middle

Eocene Naoprdan Shally Group of northeast Iraq. Sharbazheri reported this species

from the Middle Eocene in the Avanah Formation, northern Iraq. Al-Hashimi and

Amer, (1985), Abawi and Sharbazeri, (1987) described it from the Middle Eocene in

the middle part of the Geli Duhok section, northeastern Iraq. In the present study,

163

Alveolina elliptica is common in the former Qulqula Conglomerate Formation of the

Middle Eocene age.





Type Species - Alveolina daniensis Drobne, 1977

Alveolina daniensis Drobne, 1977; vol. 99, p. 20, pl. 1, figs.17-20


Distinguishing characteristics: The test circular, in transverse section, the whorls are

very much close to each other and there are 6-8 whorls. The lines of accretion

parallel to the septum in the basal layer of flosculinized whorls. The form is

megalospheric and the initial chamber is sub circular.

Remarks: Alveolina daniensis, reported from the Lower most Eocene rocks of

Slovenia. Alveolina were common larger benthic foraminifera in the late Paleocene

and Early to Middle Eocene Tethyan (Neotethyan) shallow-water carbonate

platforms (Hottinger 1960). During this timespan, alveolinids represent important

sediment contributors to shallow-water carbonates of the eastern Adriatic cost,

adjacent mainland regions and off -shore wells. In the early Ilerdian (SBZ 5 and

SBZ 6) moderate sized, spherical and flosculinized alveolinids (Alveolina aramaea

Hottinger 1960, A. globosa (Leymerie) 1846, A. daniensis Drobne 1977, A. solida

Hottinger 1960) and the ovoidal to elongated A. vredenburgi Davies and Pinfold

1937 and A. ellipsoidalis Schwager 1883 settled on middle ramp sandy to muddy

164

bottoms, from the Pyrenees, to the Northern and Southeastern parts of the PgAdCP,

and eastwards to Turkey. The largest Ilerdian spherical species, A. aramaea

Hottinger 1960, A. daniensis Drobne 1977, A. dedolia Drobne 1977, A. pisella, and

A. brassica, occurred in the eastern (Neo) Tethys, Sirel and Acar (2008).



Stratigraphic range (Age): Lower Eocene


Type Species - Alveolina ellipsoidalis Schwager, 1883

Alveolina ellipsoidalis Schwager, Schwager 1883, pl.25, figs. 1-2,

Alveolina ellipsoidali Hottinger, 1960, p. 64, text figs, 20c, 33a, b, pl. 2, figs. 1-8.

Alveolina ellipsoidali Devoto, 1964, pl. 2, fig. 2.

Alveolina (Alveolina) ellipsoidalis Hottinger, 1974, p. 41, pl. 33, figs. 1-7.

Alveolina ellipsoidali Drobne, 1977, pl. 1, fig. 1-3.

Alveolina ellipsoidali Accordi, Carbone and Pignatti, 1998, pl. 18, fig. 1.


Distinguishing characteristics: Test oval, in axial outline with rounded poles, tightly

coiled, Basal layer very thin, thickening only gradually in axial direction. Growth

stages indistinct. Spherical megalospheric with a diameter of average 0.25mm.

Elengation index of 1.5 in megalospheric specimens. 9-12 whorls. Axial length 3.5

mm, equatorial diameter 2.5 mm. Small sized chamberlets, numerous, rounded in

sections of the early 5 whorls, large and oval in subsequent whorls; chamberlets size

increase with growth. In the last whorl, the chamberlets are more closely spaced

165

than in the previous one. At a redious of 1 mm there are 7-8 chamberlets per mm.

Intercalary chamberlets very few.

Remarks: Babazadeh (2011), studied East Nehbandan, Mahrud regions and South

Birjand secctons of Early Paleogene rocks of eastern Iran, the lower part of this

formation consists predominantly of thick graded boulder to pebble conglomerate

and gray calcareous limestones. This part continues with thin-bedded marl at top of

section. The calcareous limestones yield the following benthic foraminifera:

Opertorbitolites douvillei (Nuttall), Alveolina solida Hottinger, Alveolina

ellipsoidalis Schwager, Alveolina pasticillata Schwager, Lockhartia conditi

(Nuttall), Nummulites globulus Leymerie, Assilina laminosa Gill, Discocyclina

dispansa Sowerby,

Discocyclina ranikotensis Davies and Pinfold, Discocyclina sp., Ranikothalia

sindensis (Davies) and miliolids. This spacies represents an index species and is

correlative with SBZ 6 (Ilerdian, Lower Ypresian, and Lower Eocene) of proposed

biozonation of Serra-Kiel et. al. (1998). It indicates an Early Eocene age.



Stratigraphic range (Age): Early Eocene


Type Species - Alveolina cf. elliptica (Sowerby),

Alveolina elliptica nuttalli Davies L., 1940, p. 219,221, pl. 12, figs. 1-4.

Alveolina elliptica (Sowerby) var. flosculina Silvestri. Smout A. H., 1954, p. 82,

pl.14, figs.8-12

166

Alveolina elliptica nuttalli Davies, Hottinger L., 1960, p. 146, pl. 12, fig. 4.

Alveolina elliptica (Sowerby), Hottinger L., 1960, p. 146, pl. 12, figs. 1-3.

Section: 5, Figures: 5.40 and 5.41

Distinguishing characteristics: The test elliptical, in axial outline with rounded poles,

tightly coiled, wall porcellaneous, imperforate, basal layer very thin, thickening only

gradually in axial direction.Growth stages indistinct. The form is megalospheric and

the initial chamber is sub circular to oval with a diameter of average 0.25mm. size

relatively large attaining (4.5-6.5 mm) in length and (2.5-3.0 mm) in diameter,

length / diameter average ratio is 2:1, whorl 9-12 in number along the shorter axis,

in transverse section, the whorls are very much close to each other. Septula

alternating is adjacent chambers. Small sized chamberlets numerous, rounded in

sections of the early 4 whorls, gradually larger and oval in subsequent whorls;

chamberlets size increase with growth. In the last whorl, the chamberlets are more

closely spaced than in the previous one. At a redious of 1mm, there are 7-8

chamberlets per mm.

Remarks: Babazadeh 2008, studied the Early Eocene succession of bioclastic

limestones of Lower Eocene transgressive succession of Sahlabad province, eastern

Iran, and is marked by the presence of Discocyclina dispansa Sowerby, Lockhartia

conditi (Nuttall), Opertorbitolites douvillei (Nuttall), Alveolina pasticillata

Schwager, Assilina laminose Gill, Alveolina cf. elliptica (Sowerby), etc. and this

assemblage is attributed to the shallow benthic inner shelf environment. This

shallower water orthophragminid assemblage is correlative with SBZ 6 (Ilerdian,

Lower Ypresian, and Lower Eocene) of proposed biozonation of Serra-Kiel et. al.,

(1998). It indicates an Early Eocene age.

167





Type Species - Alveolina decipiens Schwager,

Alveolina (Flosculina) decipiens Schwager, Schwager 1883, p. 103, pl.26, fig.1.

Alveolina aff.subpyrenaica (Leymerie)-Hottinger, 1958, fig 8d.

Alveolina decipiens Hottinger, 1960, p. 123, text figs.66a-e, 70g, pl. 8, figs. 1-3.

Alveolina decipiens Gohrbandt and Hottinger, 1967, p. 700, text figs. 3a-g.

Alveolina (Alveolina) decipiens Hottinger, 1974, p. 66, pl. 97, figs. 1-7.

Alveolina (Alveolina) decipiens Drobne, 1977, p.35, pl. 5, figs. 20-21, text fig.17.


Distinguishing characteristics: Megalospheric form. Test ovoidal with rounded

poles, Growth stages indistinct, chamberlets size increase with growth. Early stage

composed of five subspherical tight whorls with thin basal layer; adult stage

moderately elongated and with very thick basal layer. Eight whorls. Chamberlets

large and circular in the axial section of the early five (5) whorls, then irregular in

shape and large. Few intercalary chamberlets in outer whorls. Adult growth stages

irregular in all test characters. No supplementary passages in the basal layer.

Proloculus spherical with a diameter greater than 0.25mm. Axial length 3.4mm and

equatorial diameter 2.2mm. Elongation index close to 1.5

Remarks: This spacies is a particularly variable species difficult to delimit from

others, consequently its range is not very well established, and is correlative with

168

SBZ 7-SBZ 9 (Middle Ilerdian, Lower Ypresian, Lower Eocene) of proposed

biozonation of Serra-Kiel et al. (1998). This species is also reported from SBZ 7

zone of Egypt indicates an Middle Ilerdian, Lower Ypresian, Lower Eocene age and

Trentinara formation, Capaccio Vecchio, Southern Apennines, Italy (Vecchio et.al.,

2007)





Type Species - Alveolina cf. dainellii Hottinger, 1960

Alveolina dainellii Hottinger, 1960, Pl. 5, Figs. 12-14; Fig. 53

Alveolina cf. dainellii Hottinger, Nicora & Silva, 1990, Sample 115-715A-19R-1,

Pl. 1, Figs.4 and 6


Distinguishing characteristics: The test is circular to elliptical in transverse section,

common specimens frequently not complete and not oriented. Diameter in the most

complete specimens: 3.5-4 mm. Chamberlets low and wide. Several specimens show

basal thickening and coiling rate close to A. dainellii. The form is megalospheric and

the initial chamber is sub circular to oval.

Remarks: These Paleogene shallow-water larger benthic foraminifers recovered

from Holes 714A and 715A during Ocean Drilling Program (ODP) Leg 115 in the

Indian Ocean located on the eastern margin of the Maldive Ridge (Nicora and Silva,

1990). The biostratigraphic range of defines SBZ 11 (Middle Cuisian, Early Late

169

Eocene): Alveolina dainellii, A. aff. canavarii, A. histrica, A. decastroi, A. cremae,

Nummulites praelaevigatus, N. burdigalensis Cantabricus, N. kapeliosi, N. escheri,

N. nitidus, N. archiaci, Assilina laxispira and Discocyclina fortisi simferopolensis

(Serra-Kiel et al., 1998).



Stratigraphic range (Age): Early Late Eocene


Type Species - Alveolina aragonensis Hottinger, 1960

Alveolina aragonensis Hottinger, 1960, PI. 6, Figs. 5-10; Fig. 60 (b-f);

Alveolina aragonensis Hottinger, Drobne, 1977, PI. 5

Alveolina aragonensis Hottinger, Nicora and Silva, 1990, Sample 115-715A-21R,

PI. 3, Fig.1


Distinguishing characteristics: Test oval, in axial outline with rounded poles, tightly

coiled, Basal layer very thin, thickening only gradually in axial direction. Growth

stages are indistinct. Spherical megalospheric and the axial length 5mm, equatorial

diameter 3.5mm; length/width ratio: 1.5, whorls 9-16. Small sized chamberlets,

numerous, rounded in sections of the early 5 whorls, large and oval in subsequent

whorls; chamberlets size increase with growth. In the last whorl, the chamberlets are

more closely spaced than in the previous one. At a redious of 1 mm there are 7-8

chamberlets per mm. Intercalary chamberlets very few.

170

Remarks: The specimen displays narrow and high chamberlets; a moderately, rather

regularly increasing spire, with a thin basal thickening in the equatorial region and

slightly more development at the poles; and a general shape that is a little more

fusiform than the typical A. aragonensis. Erdem et. al. (2007), described the

claystone-limestone succession of Ilerdian-Cuisian limestones of Southern

Eskişehir, Central Turkey, and their comparative stratigraphic distribution with

abundant benthic foraminifera, particularly species of Alveolina d’Orbigny (1826) of

Tethyan Eocene time. The Ilerdian unit of the study area is characterized

by Alveolina species, such as Glomalveolina lepidula, G. minutula, G. karsica, A.

vredenburgi, A. ellipsoidalis, A. avellana, A. aff. minervensis, A. dedolia, A.

moussoulensis, A. subpyrenaica, A. laxa, A. aragonensis, A. varians, A.

ilerdensis, A. trempina, A. citrea, A. pisella and A. decipiens.



Stratigraphic range (Age): Early Eocene to Middle Eocene

Genus - Alveolina D'Orbigny, 1826;

Type Species - Alveolina nuttalli (Davies, 1940)

Alveolina elliptica nuttalli Davies, 1940, p. 219- 220, pl. 12, figs. 1-4

Alveolina elliptica flosculina Silvestri, 1954, Smout, p. 82-83, pl.14, figs. 8-12

Alveolina nuttalli (Davies), 1993, Samanta, p. 65-72, pl.10, figs. 1-5; pl. 11, figs.2-3.


Distinguishing characteristics: The shape of the test is ovoid with rounded poles.

Axial diameter ranges from 4mm to 5.5mm, equatorial diameter from 2.6mm to

171

3.8mm and index of elongation from 1.44 to 1.54. All the sections and incomplete

specimens examined were megalospheric. The shell of the species composed of

three growth periods. The spheric megalosphere (its diameter ranges from 0.170mm

to 0.185mm) is followed by tight-coiled ovoid 5-7 whorls of the nepionic stage. The

number of the flosculinized whorls ranges from 2 to 3. The ovoid 7-8 whorls of the

senile period are coiled tightly in the axial as well as the equatorial spire. The size of

the chamberlets increase gradually from the proloculus to the last whorl; their cross

section are generally subspheric.

Remarks: Four specimens collected from the upper Kirthar beds (middle Eocene) of

north-west India were described and figured as Alveolina elliptica (Sowerby) nuttalli

Davies by Davies (1940), in spite of the fact that the alveolinid association consists

of different two species. The first alveolinid species illustrated in Davies (1940)

resembles A. elliptica Sowerby by large test with tightly coiled numereous whorls

Hottinger (1960). The second species A. elliptica Nuttalli figured in Davies (1940)

have an ovoid test including the ovoid nepionic

Documents

PALAEONTOLOGICAL STUDY - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/73160/13/13...Benthic foraminifera have been divided into, morphogroups based on the test shape and these