Persian Permian Fusulinids:
DAVYDOV &
AREFIFARD

Plain-Language &
Multilingual  Abstracts

Abstract

Introduction and Previous Work

Geologic Setting

Stratigraphy and Sedimentology

Systematic Paleontology 

Correlation and Biostratigraphy of the Khan Formation with Correlative Peri-Gondwana Deposits

Age of Peri-Gondwanan Eoparafusulina and Perigondwania-Neodutkevitchia Assemblages

Paleobiogeographic and Paleotectonic Implications of the Perigondwania-Neodutkevitchia Assemblages from Khan Formation

Conclusions

Acknowledgements

References

Test

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SYSTEMATIC PALAEONTOLOGY

All specimens are housed at the Paleontology Repository, Department of Geosciences, University of Iowa. SUI 102968 to 103100

Order FUSULINIDA Fursenko, 1958
Family SCHUBERTELLIDAE Skinner, 1931
Subfamily SCHUBERTELLINAE Skinner, 1931
Genus GROVESELLA, new genus

v. 1937 Eoschubertella Thompson, 1937; Thompson, p. 123 (partim)
v. 1994 Eoschubertella Thompson, 1937; Groves et al., p. 32 (partim)
v. 1949 Schubertella Staff and Wedekind, 1910; Suleimanov, p. 27-28 (partim)
v. 1951 Schubertella Staff and Wedekind, 1910; Rauser-Chernousova, Bensh, Vdovenko, Gibshman, Leven, Lipina, Reitlinger, Solovieva and Chedia, p. 69 (partim)
v. 1969 Schubertella Staff and Wedekind, 1910; Manukalova-Grebenjuk, Il'ina and Serezhina p. 82 (partim)

Type species. Grovesella tabasensis new species, Latest Sakmarian-early Artinskian, Madbeiki section, Kalmard area, East-Central Iran.

Diagnosis. Small, nautiloid to nearly globular schubertellides with form ratio equal or less than one.

Description. Test very small to moderate in size for this group of schubertellids discoidal to nautiloid or nearly globular, with broadly rounded periphery and weakly to mildly umbilicate flanks. Coiling skewed in initial one or two volutions or can be nearly straight. Length of the test is equal or less than width and consequently the means of form ratio is equal or less than one. Wall thin, poorly visible, most probably two layered with darker and thin tectum and slightly lighter, structureless primatheca. Chomata not observed in type species, but present in the other, predominantly Pennsylvanian representatives of the genus.

Other species. Grovesella mosquensis (Rauser in Rauser-Chernousova et al. 1951); Grovesella compressa (Rauser in Rauser-Chernousova et al. 1951); Grovesella miranda (Leontovich, in Rauser-Chernousova et al. 1951); Grovesella globulosa (Safonova, in Rauser-Chernousova et al. 1951); Grovesella pseudoglobulosa (Safonova, in Rauser-Chernousova et al. 1951), Grovesella borealis (Rauser in Rauser-Chernousova et al. 1951)all from Moscovian of Russian Platform and surrounding areas; Grovesella sphaerica (Suleimanov 1949); Grovesella staffelloides (Suleimanov 1949) from late Asselian and Sakmarian in the Urals-Arctic, Tethys and Kalmard area in Central Iran.

Etymology. The genus is named after John R. Groves in recognition of his contribution to the study Upper Paleozoic fusulinids and smaller foraminifers.

Remarks. The major distinguishing feature of this genus is an exceptionally small size, and a nautiloid to nearly globular shape with form ratio equal or less than one. The genus possesses a typical schubertellids feature: small size, skewed to straight coiling, thin, obscure, but differentiated wall. However, the test of Grovosella takes a nautiloid to spherical shape with form ratios less than one and indeed a very small size. Groves (Groves et al. 1994, p. 33) noted a significant difference of these forms from typical Eoschubertella.

In all likelihood, Grovosella derived from Semistaffella sometime in the early Bashkirian, since both genera possess similar coiling, test shape and a two- to three-layered (but obscure in terms of exact differentiation of the layers) wall. Probably due to its small size and rare occurrence Grovesella are not known from the Bashkirian. However, some of the subglobular "Schubertella" described from early to late Bashkirian (Manukalova-Grebenjuk et al. 1969; Nikolaev 1989) are most likely Grovesella. This genus becomes more abundant in the Moscovian. The second acme of the genus is late Asselian-Sakmarian through early Artinskian at least in the Urals-Arctic, Carnic Alps-Chios, Nevada and Kalmard area in Central Iran.

Range. Urals-Arctic, Carnic Alps-Chios and Kalmard area in Central Iran; Bashkirian(?)-Artinskian.

Grovesella tabasensis, new species
Figure 4, Figure 4.12-4.16

Holotype. SUI 102982. Axial section; sample R-49-3, Madbeiki section, Khan Formation, unit 8, 134 m above the base of the section; Kalmard area, East-Central Iran; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Two axial, two tangential, and one saggital sections from the Khan Formation, Central Iran, and over 20 axial sections from Eoparafusulina linearis beds, Bird Springs Formation, Artinskian, and Arrow Canyon, Nevada.

Description. Test is very small with 3-3.5 volutions, nautiloid with broadly rounded periphery and mildly umbilicate flanks. Coiling is slightly skewed in initial one or two volutions or nearly straight. Length of the test is 165-200 microns, diameter (width) 210-290 microns, with form ratio of the last volution of 0.6-0.85. Outer diameter of proloculus is 35-50 microns. Thickness of the wall in the final volution is 7-10 microns. Wall thin, poorly visible, most probably two layered with darker and thin tectum and slightly lighter, structureless primatheca. Chomata and tunnel were not observed among the studied specimens. Chamber count was available only in one specimen and it is 12-13 in final volution.

Etymology. After the Tabas city and area where this genus has been found.

Types. The specimen illustrated in Figure 4.15 (SUI 102982) is designated as the holotype, which is from the Khan Formation of the Madbeiki section, 134.0 m above the base of measured section (Figure 4). Other illustrated specimens are designated as paratypes (Figure 4.12-5.19; SUI 102979, SUI 102980, SUI 102981, SUI 102982, SUI 102983, SUI 103062, SUI 103063, SUI 103064).

Remarks. A very small size, small number of volutions, and a nautiloid shape of the test make this species very distinct from the rest of the genus. Grovesella tabasensis could be compared to Grovesella staffelloides (Suleimanov 1949) from late Asselian and Sakmarian of Southern Urals. It has a very similar test shape, wall structure and straight coiling, but differs from staffeloides in the smaller size of corresponding volutions, a smaller proloculus and tighter coiling. Many specimens of Grovesella tabasensis have been found recently in Eoparafusulina linearis beds, Arrow Canyon, Nevada, i.e., eventually from the same stratigraphic level.

Stratigraphic range. Khan Formation; Madbeiki section sample M49; Permian, Cisuralian, Latest Sakmarian-early Artinskian; Bird Spring Formation, Arrow Canyon, Nevada, Eoparafusulina linearis beds, Artinskian.

Geographic occurrence. Kalmard area, East-Central Iran; Arrow Canyon, Nevada.

Genus EOSCHUBERTELLA Thompson, 1937
EOSCHUBERTELLA sp. 1
Figure 4.17

Remarks. Only one paraxial section has been found in the studied material. This specimen is very small, and because of poor preservation and orientation, the important morphological features characteristic for species taxonomy cannot be observed. An elongate fusiform outline and especially small size distinguish this form from many Schubertella. However, without seeing the early volutions it is difficult to designate the precise taxonomy of this specimen.

Stratigraphic range. Khan Formation; Madbeiki section, sample M49; Pennsylvanian-Permian.

Geographic occurrence. Global distribution within tropical-subtropical belts.

Family SCHWAGERINIDAE Skinner, 1931
Subfamily MONODIEXODINIINAE Kanmera, Ishii and Toriyama, 1976
Genus EOPARAFUSULINA Coogan, 1960

v. 1960 Parafusulina (Eoparafusulina) Coogan, p. 262.
v. 1965 Eoparafusulina Skinner and Wilde, p. 73.
v. 1966 Alaskanella Skinner and Wilde, p. 57.
v. 1967 Eoparafusulina Ross, p. 944.
v. 1975 Eoparafusulina Rosovskaya, p. 106.
v. 1996 Eoparafusulina Rauser-Chernousova, Bensh, Vdovenko, Gibshman, Leven, Lipina Reitlinger, Solovieva and Chedia, p. 141-142.

Type species. Parafusulina gracilis (Meek), Thompson, et al. 1946, p. 31-32, PI. 1, figs. 6-10 (neoholotype pl. 1, fig. 10).

Discussion. Although the concept of the genus and its type species has been amended and modified several times, the taxonomy is far from being clear owing to complications with designation. Skinner and Wilde (1965, p.73-74) thoroughly quoted the original concept of the genus by Coogan (1960) and the original description of the genus type by Meek (1864). They suggested that the species described by Thompson et al. (1946) differs from Fusulina gracilis Meek (1864) because of a considerable discrepancy between dimensions as cited by Meek and Thompson and Wheeler. It should be noted that Meek described his species based on the external study of small, slender, subcylindrical forms. Unfortunately, the specimen of Fusulina gracilis from Meek's collection has been lost and therefore its internal morphology, which is absolutely critical for understanding species and genus concept, can never be distinguished. Moreover, there is no certainty about the generic nature of this taxon. Meek's specimens could potentially be Schubertella, young specimens of Pseudofusulina, or the Schwagerina, which are reported by Thompson et al. (1946) from the type locality.

Skinner and Wilde (1965, 1966) proposed a new concept of the species based on topotypes. The dimensions closely resemble Meek's description but are two or more times smaller then the specimens described as Parafusulina gracilis (Meek), by Thompson et al. in 1946. The situation becomes more complex as Skinner and Wilde (1965) did not designate a neotype or neoholotype for the Eoparafusulina gracilis Meek (1864) when they re-described it. The majority of fusulinid workers use Parafusulina gracilis (Meek), sensu Thompson et al. (1946) as a type of the genus for the Eoparafusulina. Consequently, the modern concept of Eoparafusulina genus ties to this species (Rosovskaya 1975; Rauser-Cheronusova et al. 1996; Ueno 2006).

To avoid any further complications in regard to the taxonomic stability of Eoparafusulina, the following can be proposed: According to article 24.2.1. "Statement of the Principle of the First Reviser" of the International Code of Zoological nomenclature (ICZN), "When the precedence between names or nomenclatural acts cannot be objectively determined, the precedence is fixed by the action of the first author citing in a published work those names or acts and selecting from them; this author is termed the 'First Reviser'. Because Thompson, et al. (1946) were the first who fixed the Parafusulina gracilis name by designation of the holotype (neoholotype in their definition) and provided adequate description, measurements and photographs that undoubtedly designate Parafusulina gracilis for taxonomic practice, they become authors of this species. This would meet the criteria of article 11.10 of ICZN [Deliberate employment of misidentifications. If an author employs a specific or subspecific name for the type species of a new nominal genus-group taxon, but deliberately in the sense of a previous misidentification of it, then the author's employment of the name is deemed to denote a new nominal species. The specific name is available with its own author and date as though it were newly proposed in combination with the new genus-group name (see Article 67.13 for fixation as type species of a species originally included as an expressly stated earlier misidentification, and Article 69.2.4 for the subsequent designation of such a species as the type species of a previously established nominal genus or subgenus)]. Coogan (1960) designated Parafusulina gracilis (Meek) Thompson, et al. 1946 for his new subgenus Eoparafusulina. Thompson and Wheeler become authors of this species (Parafusulina gracilis Thompson, et al. 1946). According to article 75.5 of ICZN Fusulina gracilis (Meek 1864) becomes nomen dubium and is removed from taxonomic practice. For the species described by Skinner and Wilde (1965, p. 76, pl. 34, figs. 6-11) as Eoparafusulina gracilis the new name of Eoparafusulina skinnerwildei is proposed, new species with holotype figured on plate 34, fig. 7 (Skinner and Wilde 1965, p. 76). Eoparafusulina thompsoni (Skinner and Wilde 1965) becomes a junior synonym of Parafusulina gracilis (Thompson, et al. 1946).

It is difficult to add anything to an excellent diagnosis of Eoparafusulina proposed by Skinner and Wilde (1965, p. 75) except the stock of subglobular fusulinids with form ratios less than 3.5 that were described as McCloudia (Ross 1967) and have to be excluded from the genus. As a result of the transitional character of evolution between Eoparafusulina and Monodiexodina (Ueno 2006) some species can be placed in either genus only conventionally. Consequently, the concept of the genera depends on species composition.

The following adjusted diagnosis can be proposed for Eoparafusulina:

Test is medium to large, elongate to short subcylindrical usually around 10 mm in length, but might exceed 15 mm. Mature individuals possess 5 to 8 volutions and are bilaterally symmetrical. Proloculus is small to large, its outside diameter in general is around 200 microns, but on some megalospheric specimens might reach up to 400 microns. Spirotheca is relatively thin, gradually increasing in thickness throughout the growth; its thickness in final volution does not usually exceed 100 microns. In addition, the spirotheca is composed of smooth and very thin tectum and fine alveolar keriotheca. The test is rather tightly coiled and expanding uniformly. Phrenotheca are absent. Septae are strongly fluted from pole to pole. Septal folds are well developed along the lower half of the septa, and opposing folds of adjacent septa meet. Low cuniculi form in the outer volutions at those places where opposing septal folds adjoin. Secondary deposits coat septal folds in all but the outer half volution and form conspicuous, sometimes significant axial deposits. Rudimentary chomata are present in proloculus, sometimes in first volution; in the rest of volutions chomata are replaced by pseudochomata that are adjacent to the tunnel.

Remarks. Eoparafusulina is much like Monodiexodina (Sosnina 1956) in many respects. In fact, these genera are evolutionarily related to each other (Ueno 2006). Still, Eoparafusulina has a smaller size and form ratio (> 7 in Monodiexodina according to Ueno 2006), less dense axial fillings and less well-developed septa. Cuniculi are mostly present in one to two outer volutions in Eoparafusulina as opposed to well-developed cuniculi in many volutions including the inner one in Monodiexodina. Eoparafusulina also resemble elongate subcylindrical Parafusulina, but are smaller in size, and have tighter coiling, as well as specific septal fluting where septal folds are developed along the lower half or less of the septa. The genera also differ in stratigraphic range. Eoparafusulina is found in the Sakmarian-Artinskian, wereas subcylindrical elongate Parafusulina are generally found post Artinskian.

A group of small Eoparafusulina-like fusulinids from the Arctic appear to belong to a separate and distinct group described here as a new genus Timanites (see below).

Stratigraphic range. Permian, Cisuralian, Late Asselian-Artinskian and ?Kungurian.

Geographic occurrence. Global distribution within tropical-subtropical belts.

Eoparafusulina grozdilovae, new species
Figure 5.1-5.4

v. 1993 Eoparafusulina tschernyschewi tschernyschewi (Schellwien 1909), Leven, p. 178, pl. 10, figs. 7, 8, 11.

Holotype. SUI 102990. Axial section; sample M-50-26, Madbeiki section, Khan Formation, unit 15, 136 m above the base of the sections; Kalmard area, East-Central Iran; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Description. Test is large in size, subcylindrical to slightly fusiform with bluntly rounded poles. First volution is ellipsoidal to inflated fusiform. Volutions expanded along the axis gradually in early 3-4 volutions and more rapidly in the following ones. Coiling is generally moderate and gradual throughout the development, but slightly tighter in the early 3-4 volutions. Mature specimens of 6-8 volutions are 6.2-9.8 mm in length and 2.4-3.6 in diameter with form ratios of 2.5-2.7. The first volution is 0.25-1.25 mm long and 0.23-0.36 wide, giving form ratios of 1.1-2.3. The length and diameter of the fourth volution are 3-3.7 mm and 1-1.2 mm with form ratios of 2.5-3.7. Spherical proloculus is medium in size, its outside diameter 125-250 microns. Spirotheca is moderately thin and composed of thin and dark tectum and thick and coarsely alveolar keriotheca. It is thin in the early 3-4 volutions and gradually thickens in succeeding ones. The thickness of spirotheca in the first, fourth and last volutions of 5 specimens are 20-30, 40-70, 70-80 microns, respectively. Septae are thin to moderate in thickness, usually around 30-50 microns, and twice as thin as the wall in respective volutions.

The widely spaced septae are regularly and narrowly fluted throughout the length of the test, with fluting extending half or less than half as high as chambers. Tunnel is very narrow in early volutions and widens with a rather irregular path in late volutions. Chomata are very small, rounded and observed in proloculus and first volution. Chomata are not distinguishable in the other volutions, where tunnel is outlined with pseudochomata. Axial fillings vary from significant to very weak and developed in polar ends of second to fifth volutions.

Etymology. The species named in honor of Russian fusulinid worker Ljudmila P. Grozdilova, who studied Eoparafusulina in the Arctic.

Material examined. Ten axial and seven paraxial sections from Madbeki section in Kalmard area, East-Central Iran.

Remarks. Eoparafusulina grozdilovae draw a likeness to Eoparafusulina tschernyschewi tschernyschewi (Schellwien 1909) from Russian Arctic. Some specimens of E. grozdilovae from Peri-Gondwana (Central Pamir) have even been described under this name (Leven 1993, p.178). The major difference between these two species is that E. grozdilovae possess a much thinner septa in all volutions. The septa of E. tschernyschewi tschernyschewi and related species from Russian Arctic are as thick as the wall in all volutions (Grozdilova and Lebedeva 1961, p. 219-220), whereas septa in E. grozdilovae (especially in the final volution) are more than two times thinner than the wall. Moreover, E. grozdilovae has less well-developed axial fillings, a slightly more fusiform outline and a wider tunnel, especially in the final volution. There are two other major contrasts that allow differentiation between these species. First, they appear in opposite sides of tropical belt: E. grozdilovae is found in the southern antitropical (subtropics) area and E. tschernyschewi tschernyschewi in the northern antitropical area. Second, the stratigraphic range of E. tschernyschewi tschernyschewi is very narrow: it is present only in the uppermost Asselian-lowermost Sakmarian, whereas the stratigraphic range of E. grozdilovae is present in the uppermost Sakmarian-lower Artinskian. Finally, specimens of E. grozdilovae from Central Pamir are rather similar to the population from the Kalmard area and differ from the latter only in better developed axial fillings.

Stratigraphic range. Bed 6, Dangikalon Formation, samples G-83, M-49-50, Khan Formation; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeki and Gachal sections in Kalmard area, East-Central Iran; Kalaktash area, Central Pamir, Tadzhikistan.

Eoparafusulina stevensi, new species
Figure 5.5-5.10

v. 1993 Eoparafusulina tschernyschewi memoranda (Grozdilova and Lebedeva, 1961), Leven, p. 178, pl. 11, figs. 2, 3, 6.

Holotype. SUI 102996. Axial section; sample M-50-4, Madbeiki section unit 15, 136 m above the base of the sections, Kalmard area, East-Central Iran; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Fourteen axial and eight paraxial sections from Madbeiki section in Kalmard area, East-Central Iran.

Description. The test is large in size, sub-cylindrical with bluntly rounded poles, first volution is ellipsoidal to inflated-fusiform with lateral slopes that are sub-parallel across the central half of the shell and uniformly or irregularly convex in the end quarters. The expansion of volutions changes during growth, for it gradually increases in axial extension in the first 2-4 volutions and then attains to more expanded polar ends in later volutions. Coiling tight to moderate in the early 3-4 volutions and uniformly and gradually coiled in the late volutions. Mature tests of 6-6.5 volutions are 5.8-7.2 mm long and 1.8-2.3 wide with form ratios of 3.1-3.2. First volution is 0.4-0.7 mm long and 0.25-0.29 wide, giving form ratios of 1.6-2.4. The length and diameter of the fourth volution are 3-5 mm and 1-1.4 mm, respectively, with form ratios of 3-2.8. The proloculus is medium to large in size, spherical, with outside diameter of 150-250 microns averaging 210 microns for six specimens. Spirotheca is composed of tectum and keriotheca; it is relatively thin in early volutions and gradually thickens after the third-fourth (earlier mentioned "3-4") volution. The thickness of spirotheca in the first, fourth and last volutions of five specimens are 20-30, 40-60, 70-80 microns, respectively. Septae are thin to moderate 20-50 microns and usually twice as thin as wall in respective volutions. They are widely spaced and rather narrowly fluted throughout the length of shell, the fluting extending to half the height of chambers. Very low and poorly developed cuniculi can be observed only in the final volution. The tunnel is narrow and low in early volutions and becomes rapidly wide with a rather irregular path in late volutions. The chomata are small and rounded in theirst volution but indistinct in other volutions. It seems to be pseudochomata that outline the tunnel after first volution. Weak to very weak axial fillings are present in axial ends of 2-4 volutions.

Etymology. Species named in honor of Calvin Stevens, well-known Permian fusulinid and coral worker.

Remarks. Eoparafusulina stevensi shares many characteristics with Eoparafusulina tschernyschewi memoranda (Grozdilova and Lebedeva 1961) from the Russian Arctic, but has much thinner septa in all volutions. These septae are twice or more times thinner than the wall, as opposed to the thick septa that are equal in thickness to wall in E. tschernyschewi memoranda. Also, E. stevensi features a wider tunnel and less well-developed axial fillings. Specimens of E. stevensi from Central Pamir (Leven 1993) are similar to the population from the Kalmard area in all respects.

Stratigraphic range. Bed 6, Dangikalon Formation, Khan Formation samples M49-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki section in the Kalmard area, East-Central Iran; Kalaktash area, Central Pamir, Tadzhikistan.

Eoparafusulina madbeiki, new species
Figure 5.11-5.14

Holotype. SUI 103004. Axial section; sample M-50-19, Madbeiki section, Khan Formation, unit 15, 136 m above the base of the sections; Kalmard area, East-Central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Eight axial and four paraxial sections.

Description. Test is of large size, subcylindrical to elongate fusiform with bluntly rounded to slightly pointed poles. First volution is sub-ellipsoidal to fusiform. The test expands slowly along the axis during the first 3-4 volutions, but beyond this the volutions expanded more rapidly. The test is gradually and moderately coiled throughout the development, but slightly tighter in the early 2-3 volutions. Mature specimens of 6.5-7.5 volutions are 7.3-8.5 mm long and 1.9-2.2 wide with form ratios of 3.4-4.5. The first volution is 0.4-0.6 mm long and 02-0.3 wide, giving form ratios of 1.5-2.2. The length and diameter of the fourth volution are 2.5-3.2 mm and 0.8-0.9 mm with form ratios of 2.7-4. Proloculus is spherical and medium to large in size with an outside diameter of 180-300 microns. Spirotheca is moderately thin and composed of thin and dark tectum and thick and coarsely alveolar keriotheca. It is thin in the early 3-4 volutions and gradually thickens in the following volutions. The thickness of spirotheca in the first, fourth and last volutions of four specimens are 20, 40 and 60 microns, respectively. Septae are thin to moderate in thickness about 30-50 microns, which is less than wall in all volutions. Septae are widely spaced, moderately and narrowly fluted throughout the length of the test, with fluting extending to half or less than half as high as chambers. The tunnel is very narrow and low in early volutions and widens in late volutions with irregular paths. Chomata are very small and rounded in proloculus and first volution, and pseudochomata outline the tunnel after the first volution. Axial fillings are moderate to light and developed in polar ends of 2-5 volutions.

Etymology. After the name of Madbeiki section where this species has been found.

Remarks. Eoparafusulina madbeiki can be distinguished from the comparable Eoparafusulina stevensi in its elongate-fusiform test outline in all volutions, slightly tighter coiling, more regularly fluted septa, better developed axial fillings and a narrower tunnel.

Stratigraphic range. Khan Formation samples M49B-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki section in the Kalmard area, East-Central Iran

Eoparafusulina pamirensis Leven, 1993
Figure 5.15-5.18

v. 1993 Eoparafusulina pamirensis Leven, p. 180-181, pl. 12, figs. 9-12.

Remarks. In general the population from East-Central Iran possesses a slightly larger proloculus, shorter test and narrower tunnel.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation samples G-83-84, M49-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Madbeiki and Gachal sections in Kalmard area, East-Central Iran.

Eoparafusulina ruttneri, new species
Figure 6.1-6.5

Holotype. SUI 103004. Axial section; sample M-49-5, Madbeiki section, Khan Formation, unit 15, 135 m above the base of the sections; Kalmard area, East-Central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Four axial and seven paraxial sections.

Description. Test is of medium size, subcylindrical with bluntly rounded poles. First volution is ellipsoidal. The shell expands gradually in the early 3-4 volutions along the axis and more rapidly in succeeding volutions. The test is moderately and uniformly coiled throughout growth. Mature specimens with 6-7 volutions are 4.9-7 mm long and 1.6-2 wide with form ratios of 3.0-4.3. The first volution is 0.4-0.6 mm long and 0.3-0.4 wide, giving form ratios of 1.4-1.6. The length and diameter of the fourth volution are 1.7-3 mm and 0.8-1.2 mm with form ratios of 2.1-2.8. Proloculus is spherical, medium in size with an outside diameter of 170-220 microns. Spirotheca is composed of thin and dark tectum and thick and coarsely alveolar keriotheca. It is thin in the early 3-4 volutions, and it increases in thickness gradually in succeeding volutions. The thickness of spirotheca in the first, fourth and last volutions of four specimens are 20-30, 40-60, 60-90 microns, respectively. Septae are thin to moderate in thickness, usually around 30-60 microns, but never reached even half of the thickness of the wall in respective volutions. Septae are widely spaced and moderately and narrowly fluted but seemingly irregularly fluted throughout the length of the test of all volutions, with fluting extending half or less than half as high as chambers. The tunnel is very narrow and low in early volutions and becomes broad in late volutions. Small and rounded chomata occur only in proloculus and first volution. They are not identifiable in other volutions, where the tunnel is outlined with septa or pseudochomata. Narrow axial fillings along axis are present in 2-5 volutions.

Etymology. The species named in honor of A.W. Ruttner, a famous Austrian geologist who extensively mapped East-Central Iran and studied the Upper Paleozoic there.

Remarks. Eoparafusulina ruttneri shares some of the same features as Eoparafusulina stevensi but has a smaller test with greater form ratio, slightly tighter coiling, better developed axial fillings that are usually present in all volutions and a narrower tunnel. This species differs from Eoparafusulina regina (Nie and Song 1983a) by nearly twice as much, more regular and stronger septal fluting, and better developed axial fillings in almost all volutions as opposed to weak axial fillings in E. regina.

Stratigraphic range. Khan Formation samples M49-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki section in Kalmard area, East-Central Iran.

Eoparafusulina isobella, new species
Figure 6.6-6.8

Holotype. SUI 103003. Axial section; sample M-50-16, Madbeiki section, Khan Formation, unit 15,136 m above the base of the sections; Kalmard area, East-Central Iran; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Five axial and three paraxial sections.

Description. Test is medium in size, short and elongate-ellipsoidal with bluntly rounded poles. The test exhibits ellipsoidal to elongate-ellipsoidal outline starting from the first volution and continuing throughout the development. Consequently, the test is rather tightly but uniformly coiled throughout the growth. Mature specimens with 6.5-7.5 volutions are 5.3-6.3 mm long and 1.9-2.4 wide with form ratios of 2.4-3.3. The first volution is 0.5-0.8 mm long and 0.3-0.4 wide, giving form ratios 1.4-1.6. The length and diameter of the fourth volution are 1.7-3 mm and 1.4-2.3 mm with form ratios of 1.8-3.0. Proloculus is spherical to ellipsoidal, large in size with an outside diameter of 230-300 microns. The Spirotheca is composed of thin and dark tectum and thick and coarsely alveolar keriotheca. It is thin in the early 3-4 volutions and gradually thickens in following volutions. The thickness of spirotheca in first, fourth and last volutions of four specimens are 20-30, 30-40, 50-80 microns, respectively. Septae are thin, with thickness around 30-40 microns in final volution. They are usually twice as thin as wall in respective volutions. They are also closely spaced, uniformly and narrowly fluted throughout the length of the test. Flutings are rather regular and reaching the third or less than third of the height of chambers. A low tunnel is very narrow in early volutions and becomes slightly wider in late volutions. Chomata are small and rounded occurring only in proloculus and first volution. The tunnel is outlined with septal arches or pseudochomata in other volutions. Axial fillings are weak to moderately developed in polar ends of 2-5 volutions.

Etymology. Iso- and bella, Latin: perfect in all respects.

Remarks. Eoparafusulina isobella differs from all other species of Eoparafusulina described in this paper in its elongate-ellipsoidal test outline that is nearly the same in shape starting from the 2-3 volution, in very regular and intense septal fluting that is formed in axial sections and small and well rounded, low arches in all volutions.

Stratigraphic range. Khan Formation samples M49-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki section in Kalmard area, East-Central Iran.

Eoparafusulina shemiraniensis, new species
Figure 6.9-6.13

Holotype. SUI 103004. Axial section; sample M-49B-3, Madbeiki section, Khan Formation, unit 15, 135.5 m above the base of the sections; Kalmard area, East-Central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Seven axial and four paraxial sections.

Description. Test is medium in size, elongate fusiform with narrowly rounded poles. First volution is ellipsoidal. Volutions expanded along the axis gradually in early 2-3 volutions and more rapidly in succeeding volutions. Test is moderately and gradually coiled in general throughout the growth, but slightly tighter in the early 2-3 volutions. Mature specimens of 5.5-6 volutions posses 5.4-7.5 mm in length and 1.8-2.2 in diameter with form ratios of 3.0-3.9. The first volution is 0.3-0.8 mm long and 0.3-0.4 wide, giving form ratios of 1.0-2.0. The length and diameter of the fourth volution are 2.5-4.1 mm and 1-1.2 mm with form ratios of 2.5-3.6. Proloculus spherical to ovoid, medium to large in size, having an outside diameter of 150-350 microns. The moderately thin spirotheca is composed of thin and dark tectum and thick and coarsely alveolar keriotheca. It is thin in the early 2-3 volutions and gradually thickens in following volutions. A total thickness of spirotheca in first, fourth and last volutions of five specimens are 20-30, 50-55, 60-70 microns, respectively. Septa thin to moderate in thickness, usually around 30-50 microns, twice as thin as wall in all volutions. Septae are widely spaced, moderately and narrowly fluted throughout the length of the test, with fluting extending half or less than half as high as chambers. The tunnel is very narrow and low in early volutions and widens in later volutions with slightly irregular paths. Chomata are very small, rounded and observable in proloculus and first volution but not in other volutions. Pseudochomata and septa outline the tunnel after the first volution. Axial fillings are moderate to weak and developed along the axis in the 2-5 volutions.

Etymology. The species named in honor of Professor A. Shemirani, foraminiferal specialist of Sakhid Beshesti University, Iran.

Remarks. Eoparafusulina shemiraniensis has many of the same features as Eoparafusulina madbeiki but has a shorter test and fusiform outline with sharper polar ends, slightly less regular, but stronger and deeper septal fluting and a narrower tunnel with an irregular path.

Stratigraphic range. Khan Formation samples M49B-M50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki section in Kalmard area, East-Central Iran.

Eoparafusulina minuta, new species
Figure 6.14-6.18

v. 1993 Eoparafusulina depressa Skinner and Wilde, 1965, Leven, p. 179, pl. 12, figs. 3-8.

Holotype. SUI 103021. Axial section; sample G-83-8, Gachal section, Khan Formation, unit 15, 160 m above the base of the sections; Kalmard area, East-Central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Seventeen axial and nine paraxial sections.

Description. Test small to very small, subcylindrical to elongate fusiform with bluntly rounded poles. Coiling is moderate and uniform throughout development. Mature specimens of 5-5.5 volutions are 3.5-4.3 mm in length and 1.1-1.3 in diameter with form ratios of 3.0-3.6. The first volution is 0.4-0.7 mm long and 0.2-0.3 mm wide with form ratios of 1.9-2.5. The length and diameter of the fourth volution are 2.4-3 mm and 0.8-1 mm, respectively, with form ratios of 3.0-3.2. Proloculus is spherical, small to moderate in size, with an outside diameter of 130-200 microns. Spirotheca are thin although poorly preserved with considerable tectum and alveolar keriotheca. The thickness of spirotheca in the first, fourth and last volutions are 20, 30-50 and 50-70 microns, respectively. Septae are thin, about 30-40 microns, thinner than wall in respective volutions. Septae are widely spaced, moderately and irregularly fluted throughout the length of the test. The tunnel is low and narrow in inner volutions but expanded in outer ones with an irregular path. Chomata are small and rounded and observed only in proloculus. Axial fillings are absent or weakly developed.

Etymology. Minute: Latin word for small.

Remarks. Eoparafusulina minuta differs from many other Eoparafusulina in the small size of the test, with less then five volutions, and a less regular and well-developed septal fluting. It is similar to Eoparafusulina depressa (Skinner and Wilde, 1965, but has less well-developed cuniculi that are present and well observed in two-three outer volutions in E. depressa (Skinner and Wilde 1965, p. 76). E. minuta has very poorly developed cuniculi only in the final volution. The latter also has less regular and intense fluting of septa and a complete absence of axial fillings, although very weak axial fillings are present in one specimen from Central Pamir (Leven 1993, pl. 12, fig. 3).

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation sample M49B, Gachal section, samples G-83-84; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Central Pamir, Tadzhikistan; Gachal and Madbeiki sections in Kalmard area, East-Central Iran.

Genus TIMANITES, new genus

v. 1961 Triticites Grozdilova and Lebedeva, p. 177.
v. 1991 Triticites Konovalova, p. 92 (partim).
v. 1997 "Triticites" Remizova, pl. 1, fig. 10; pl. 2, figs.1-5.

Type of the genus. Triticites domesticus Grozdilova and Lebedeva 1961, p.185-186, PI. 3, figs. 7 and 8 (holotype), Ilibey Horizon, lower Sakmarian; Volonga River, Northern Timan, Russia.

Diagnosis. Very small subcylindrical to ovoid test, four to five tightly and gradually coiled volutions, small proloculi, weakly fluted septa, chomata at least in 3-4 inner volutions.

Description. Test is small to very small and usually does not exceed 3-4 mm in length, subcylindrical to ovoid in shape. The proloculus is also small to very small, with an outside diameter of 60-90 microns, sometimes up to 130 microns. Coiling is tight in early volutions, nearly uniform. Spirotheca is thin with fine alveolar keriotheca that was observed mostly in late volutions. Septal fluting is weakly to prominently developed in axial ends; in the last volution septae are often nearly straight or just wavy. Cuniculi were not observed. Axial fillings are absent or are weakly developed in axial ends of the final volution. Very small, rounded to trapezoidal chomata developed throughout the growth, sometimes absent in one or two outer volutions.

Other species. At the moment, this genus includes species described from Arctic: Timanites pensus (Grozdilova and Lebedeva 1961), Timanites dubius (Grozdilova and Lebedeva 1961), Timanites tersus (Grozdilova and Lebedeva 1961), Timanites cheni (Grozdilova and Lebedeva 1961), Timanites elatus (Grozdilova and Lebedeva 1961), Timanites mansus (Grozdilova and Lebedeva 1961), Timanites duplex (Grozdilova and Lebedeva 1961), Timanites paraduplex (Grozdilova and Lebedeva 1961), Timanites festus (Grozdilova and Lebedeva 1961), Timanites poljaricus (Grozdilova and Lebedeva 1961), Timanites teres (Grozdilova and Lebedeva 1961), Timanites komiensis (Grozdilova and Lebedeva 1961), Timanites recondita (Grozdilova and Lebedeva 1961), all from Nenets and Ilibey Horizons, upper Asselian and lower Sakmarian, Volonga, Indiga and Sula Rivers, Northern Timan, Russia; Timanites sterlitamakensis (Grozdilova 1936), from upper Asselian and lower Sakmarian of southern Urals. One more species placed in this genus conventionally Timanites pusilla (Schellwien 1898) that was found together with ?Paraschwagerina fusulinoides (Schellwien 1898) in Uggowitzer Breccie and most probably Sakmarian in age (Forke 2007).

Etymology. The genus is named after Timan region where this group of fusulinids were first described and where they were widely distributed.

Remarks. Timanites includes a very specific group of forms that are considered small and primitive among the other Permian schwagerinids. Originally described as Triticites, they recently were questionably assigned to Eoparafusulina (Davydov 1995; Remizova 1997). Overall, Timanites are of a much smaller size and have a small proloculus, fewer number of volutions, tighter coiling, less well-developed septal fluting, and an absence of cuniculi. They also have a small but conspicuous chomata in most volutions except the one or two outer ones. Timanites are different from the small monodiexodinid group Mccloudia (Ross 1967) in having a smaller size, tighter coiling, presence of chomata in most volutions, less well-developed septal fluting and an absence of cuniculi.

Stratigraphic range. Permian, Cisuralian, Late Asselian-early Artinskian.

Geographic occurrence. Russian and Norwegian Arctic, Urals.

Subfamily SCHWAGERININAE Skinner, 1931
Genus PERIGONDWANIA, new genus

v. 1993 Pseudofusulina Dunbar and Skinner, 1931; Leven, p. 162 (partim)
v. 1997 Pseudofusulina Dunbar and Skinner, 1931; Leven, p. 67 (partim) Artinskian, Madbeiki section, Kalmard area, East-Central Iran.

Diagnosis. Large, subcylindrical test, strongly, deeply and irregularly fluted septa, well-developed phrenotheca, lower cuniculi in the final volution.

Description. Test is large to very large and usually exceeds 7-8 mm in length, subcylindrical to cylindrical in shape. The proloculus is moderate in size, typically with an outside diameter of 100-150 microns. Coiling is moderate, nearly uniform, with early volutions coiled slightly tighter. The spirotheca is thick with coarse alveolar keriotheca and smooth and thin dark tectum. Septal fluting is well developed starting from early volutions. The septa is strongly, deeply and irregularly fluted throughout. Very low and poorly developed cuniculi are observed only in the final volutions. Well-developed phrenotheca are present in the outer 1-2 volutions. The axial fillings are weakly developed and generally absent. Very small, rounded chomata can be observed only on proloculus.

Other species. Perigondwania pamirensis (Leven 1993), Perigondwania karapetovi (Leven 1993), Perigondwania plena (Leven 1993), Perigondwania curva (Leven 1993, Perigondwania incompta (Leven 1993), Perigondwania gravis (Leven 1993), Perigondwania inobservalis (Leven 1993), Perigondwania macilenta (Leven 1993, Perigondwania perigrina (Leven) 1997 and Perigondwania pseudosulcata, new species, from Dangikalon Formation in Central Pamir from Bed Formation in Gudri-Mazar and Zone P2 of Tezak in Central Afghanistan (Leven 1993, 1997), Lupghar Formation in Karakorum (Gaetani et al. 1995) and Saiwan Formation in Central Oman (Angiolini et al. 2006); Perigondwania hordeola (Nie and Song 1983b) from Tunlonggonba Formation of Rutog, Xinzang, Tibet, Western China; Perigondwania rahdariensis new species; Perigondwania sp. 1 from Khan Fromation, Kalmard area, East-Central Iran.

Etymology. The genus is named after the Peri-Gondwanan region where this group of diagnostic fusulinids is distributed.

Remarks. This fusulinid group of the Peri-Gondwana affinity resembles Pseudofusulina in many respects and especially in the large test and its subcylindrical outline, moderate and uniform coiling, character of septal fluting, and size of proloculus. Perigondwania, however, have more irregular septal fluting, presence of well-developed phrenotheca in two late volutions, and a lower cuniculi in the final volution. Besides, it is still not clear whether or not Pseudofusulina type possess a rugosity of the tectum in the wall. The tectum of Perigondwania is smooth in all volutions. Perigondwania is most similar to Shagonella from Gzhelian-Asselian of western Tethys (Bensh 1972; Davydov 1986; Ueno et al. 1995) in test size, shape outline, character of coiling and especially in character of septal fluting and presence of phrenotheca and lower cuniculi in final volution of advanced forms. Shagonella possess a strong rugosity of the tectum that is lacking in Perigondwania. These genera occur in two different non-overlapped geographic areas and do not overlap in stratigraphic range. The appearance of both is a striking case of homeomorphism that is quite common in fusulinid evolution. The character of the development of Shagonella that has been established in great detail (Davydov 1988) suggests that species of Perigondwania recovered in Central Pamir and in the Kalmard area of Iran are advanced representatives of the genus. Discovery of smaller and less developed species can be predicted. However, it cannot be excluded that tendencies in Perigondwania evolution in Peri-Gondwana area could be different from those of Shagonella in the Tethys.

Stratigraphic range. Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Central Pamir, Central and Southern Afghanistan, Hindu-Kush, Karakorum, Rutog, Central Oman, and Kalmard area in Central-Eastern Iran.

Perigondwania pseudosulcata, new species

v. 1993 Pseudofusulina sulcata Korzhenevsky, 1940; Leven, p. 165, pl. 3, figs. 1-4.

Holotype. GGM VI-229-21 (Leven, 1993, pl. 3, fig. 4). Axial section; Dangikalon section, bed 6, Kalaktash area, Central Pamir; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Sixteen axial sections that reported in Leven's paper (Leven, 1993, p.165).

Description. The description and all measurement for this species are based on the data from Leven (1993). The test is large to very large in size, subcylindrical with bluntly to moderately pointed poles. Early volutions are inflated-fusiform to elongate-ellipsoidal. The test expands along axis rapidly but uniformly and possesses a subcylindrical outline from 3-4 volution. Proloculus is moderate in size, its out diameter 100-120 microns. Length = 0.9-1.1 mm, diameter = 2.4-2.9 mm, form ratios = 3.3-4.0. First volution length is 0.4-1.0, diameter = 0.35-0.45 and form ratios = 1.2-2.2. Coiling is moderate to slightly loose and uniform throughout the development. Spirotheca is thick with coarse alveolar keriotheca and smooth and thin dark tectum. The estimates of its thickness from Leven (1993) are 70-110 microns. Septae are strongly, regularly to irregularly fluted in all volutions. Fluting is slightly deeper and irregular in the final volution. Well-developed phrenotheca can be seen at least in the two outer volutions. No observation can be made regarding cuniculi, because the original material was not examined. However, the presence of cuniculi that appear in many other Perigondwania cannot be excluded. The narrow tunnel is present in all volutions except the final where it is wide to very wide. Axial fillings are generally absent. Very weak secondary deposits in the poles of the third volution are present in one specimen (Leven, 1993, pl. 3, fig. 3). Chomata perhaps present only in proloculus and second chamber.

Etymology. The name of the species shows a homeomorphic similarity between the true Pseudofusulina sulcata (Korzhenevsky 1940) from the Urals and Perigondwania pseudosulcata, a new species of the Kalaktash area of Central Pamir in Tadzhikistan.

Remarks. Perigondwania pseudosulcata bear a striking likeness to Pseudofusulina sulcata (Korzhenevsky 1940) in many important morphological features. However, the former has well-developed phrenotheca that have never been observed in Pseudofusulina sulcata (Korzhenevsky 1940). Several tenths of specimens of Pseudofusulina sulcata from the upper Asselian and lower Sakmarian in the Southern Urals were examined and no phrenotheca in any specimen was found. Moreover, Pseudofusulina sulcata have regular septal fluting in final volution, the tunnel uniformly widened throughout the development as opposed to irregular width throughout the development in Perigondwania pseudosulcata.

Stratigraphic range. Bed 6, Dangikalon Formation; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan.

Perigondwania rahdariensis, new species
Figure 6.19-6.24

Holotype. SUI 103022. Axial section; sample H-56-4, Halvan section, Khan Formation, unit 6, 134 m above the base of the sections, Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Eleven axial and six paraxial sections.

Description. Test is small in size, subcylindrical to cylindrical with bluntly rounded poles. Coiling in early two volutions is very tight, slightly looser in the rest of the volution. The first volution is ellipsoid to inflated fusiform, volutions expands very rapidly in length starting from the second volution and becoming subcylindrical in outline beginning from the 3-4 volutions. Mature tests of 4-5.5 have 5.5-8.4 mm in length and 1.5-1.9 mm in diameter giving form ratios of 3.2-4.4. First volution is 0.3-1 mm long and 0.2-0.4 mm wide with form ratios of 1.7-3.3. The length and diameter of the fourth volution are 3.2-4.2 mm and 0.8-1.2 mm with form ratios of 2.6-4.2. The proloculus is spherical, of small to medium size with an outside diameter of 150-270 microns. Spirotheca is composed of coarse alveolar keriotheca and smooth and thin dark tectum that increases in thickness with the growth of the individuals. The thickness of spirotheca in the first, fourth and final volutions are 20-30, 50-70, and 50-80 microns, respectively. The septae are thin, about 20-40 microns, half as thin as wall in all volutions. They are intensely and irregularly fluted throughout the length of shell from the middle poleward; folds are high, rounded to irregular in shape. Well- developed phrenotheca are present in the outer 1-2 volutions. The tunnel is very narrow to narrow throughout the growth with an irregular path. Chomata are small and asymmetrical, observable only in proloculus and first volution. Axial fillings are absent or very weak in early volutions.

Etymology. After the name of Rahdar section, where this species has been found.

Remarks. Perigondwania rahdariensis mirrors Perigondvania macilenta (Leven 1993) in the size of the test and proloculus, character of septal fluting and coiling. It is distinguished by its elongate fusiform test outline in the early volutions and its subcylindrical outline in the final volution as opposed to an ellipsoidal outline in the early volutions and elongate-fusiform in late volutions of P. macilenta. This species also differs from the latter in having looser coiling in maturity and a narrower tunnel.

Stratigraphic range. Khan Formation samples R-43-55, H-56; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Rahdar and Halvan sections in Kalmard area, East-Central Iran.

Perigondwania macilenta (Leven, 1993)
Figure 6.25

v. 1993 Pseudofusulina macilenta Leven, p. 171, pl. 7, figs. 3-7.
v. 1997 Pseudofusulina macilenta Leven, p. XI, figs. 12-19.

Remarks. Specimens from East-Central Iran in general possess slightly looser coiling and a narrower tunnel.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation, Rahdar section samples R-48-49; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. East-Central Iran; Kalaktash area, Central Pamir, Tadzhikistan; Khaftkala arae in Central Afghanistan; Kalmard area, East-Central Iran.

Perigondwania karapetovi (Leven, 1993)
Figure 7.1-7.2

v. 1993 Pseudofusulina karapetovi karapetovi Leven, p. 171, pl. 1, figs. 4-9.
v. 1995 Pseudofusulina ex gr. karapetovi karapetovi Leven in Gaetani et al. pl. 8, figs. 5-10.
v. 1997 Pseudofusulina karapetovi karapetovi Leven, p. 67-68, pl. XI, figs. 1-5.
v. 2006 Pseudofusulina ex gr. karapetovi karapetovi Leven and Gorgij ?? in Angiolini et al., pl. 1, figs. 5-6.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation samples R-48-49; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. East Hindu Kush, Pakistan, Khaftkala area in Central Afghanistan, Rahdar section in Kalmard area, East-Central Iran; Kalaktash area, Central Pamir, Tadzhikistan.

Perigondwania aghanabatii, new species,
Figure 7.6-7.9

Holotype. SUI 103034. Axial section; sample R-41, Rahdar section, Khan Formation, unit 7, 123 m above the base of the sections; Kalmard area, East-Central Iran; Permian, Cisuralian, Latest Sakmarian-early Artinskian.

Material. Nine axial, and three paraxial sections.

Description. The test is large, subcylindrical to elongate-fusiform with bluntly rounded to pointed poles. Early 2-3 volutions are fusiform to elongate fusiform with pointed poles. Test is uniformly and moderately coiled but tighter in the early 3 volutions. Specimens of 5-5.5 volutions are 8.2-10.3 mm long and 2.2-2.5 wide with form ratios of 3.5-4.5. First volution is 0.4-1.0 mm in length and 0.2-0.3 mm in diameter with form ratios of 1.7-2.7. The length and diameter of the fourth volution are 4.2-6.6 and 1-1.6 with form ratios of 4-4.5. Spherical proloculus is medium to large in size with an outside diameter of 150-250 microns. The spirotheca possess coarse alveolar keriotheca and smooth and thin dark tectum. The thickness of spirotheca for the first, fourth and last volutions is 20-30, 50-70 and 80-90 microns, respectively. Septae are thin, nearly 20-50 microns. They are strongly, narrowly and irregularly fluted throughout the length of the test, especially strong in the polar ends. Well-developed phrenotheca are present in the outer 1-2 volutions. The tunnel is low and very narrow in early volutions and widens in the following volutions, but still moderate in width in the final volution. Small and rounded chomata are observed only on proloculus. Axial fillings are absent or very weak and narrow along the axis in the early 2-3 volutions.

Etymology. After Iranian geologist Dr. A. Aghanabati who established the Khan Formation and proposed its Permian age.

Remarks. Perigondwania aghanabatii strongly resembles Perigondwania pamirensis (Leven 1993) especially in having a large test, moderate and uniform coiling, intense and irregular septal fluting, and the size of the proloculus. However, it has elongate fusiform test outline with pointed polar ends in early volutions and subcylindrical to elongate fusiform test outline in late volutions as opposed to ellipsoidal outline in the early volutions and subcylindrical outline in the late volutions in P. pamirensis. Additionally, the former has a narrower tunnel and tighter coiling especially in early volutions.

Stratigraphic range. Halvand section, sample H-56, Rahdar section, sample R-41, R-43, R-49-50, Khan Formation; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Occurrence. Kalmard area, East-Central Iran.

Perigondwania pamirensis (Leven, 1993)
Figure 7.10-7.12

v. 1993 Pseudofusulina pamirensis Leven, p. 162-163, pl. 1, figs. 1-3, 6, 8.
v. 1993 Pseudofusulina kalaktashensis Leven, p. 165, pl. 2, figs 4-6.
v. 1995 Pseudofusulina aff. syniensis Konovalova and Baryshnikov, 1980, Leven in Gaetani et al., pl. 8, figs. 2, 4.
v. 2006 Pseudofusulina kalaktashensis Leven in Angiolini et al., pl. 1, fig. 13.

Material. Twelve axial and six oblique sections.

Remarks. Pseudofusulina pamirensis and Pregondwania kalaktashiensis are synonymized because these two species resemble each other in many morphological features such as similar large test, the size of a proloculus, shape outline, relatively loose character of coiling, intense and irregular septal fluting, well-developed phrenotheca in outer 2 volutions, a narrow tunnel in the early volutions and a wide tunnel in final one. The only difference is that Perigondwania kalaktashensis has a slightly more inflated fusiform test outline in two early volutions, whereas P. pamirensis has an ellipsoidal outline in the early volutions.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation, Rahdar section, sample R-50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Rahdar section in Kalmard area, East-Central Iran.

Perigondwania inobservabilis (Leven, 1993)
Figure 7.13-7.15

v. 1993 Pseudofusulina inobservabilis Leven, p. 164, pl. 2, figs. 1-3.

Material. Six axial, two oblique sections and three paraxial sections.

Remarks. Specimens of Perigondwania inobservabilis from East-Central Iran compare well to those from central Pamir. P. inobservabilis is a little different, having a slightly larger test, being slightly looser in the last volution, having a narrower tunnel and stronger septal flutings, especially in last stage of development.

Stratigraphic range. Warfa-6 well sample WA6-11, Haushi Lm; bed 6, Dangikalon Formation; Khan Formation, Rahdar section, samples R-41, R-42, R-49, R-50, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Central Oman; Kalaktash area, Central Pamir, Tadzhikistan; Rahdar section in Kalmard area, East-Central Iran.

Perigondwania plena (Leven, 1993)
Figure 8.6-8.7

v. 1993 Pseudofusulina plena Leven, p. 164, pl. 2, figs. 1-3.

Material. Six axial and two paraxial sections.

Stratigraphic range. Bed 6, Dangikalon Formation; Lupghar Fm., sample KK20, Khan Formation Rahdar section, samples R-41, R-42, R-48, R-50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. East Hindu Kush, Pakistan; Khaftkala area in Central Afghanistan, Rahdar section in Kalmard area, East-Central Iran; Kalaktash area, Central Pamir, Tadzhikistan.

Perigondwania gravis (Leven, 1993)
Figure 8.8

v. 1993 Pseudofusulina gravis Leven, p. 170, pl. 6, figs. 6-8,10.

Material. One axial and two oblique sections.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation, Rahdar section, sample R-50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Rahdar section in Kalmard area, East-Central Iran.

Perigondwania? sp.1
Figure 8.14

Material. One axial and two paraxial sections from sample R-43, Rahdar section.

Description. Test is medium in size, short subcylindrical with bluntly rounded to slightly pointed poles. The first volution is ellipsoidal, the second-fourth volutions are inflated fusiform; and the fifth and six volutions are subcylindrical in outline. The proloculus is small, spherical with an outside diameter of 145 microns. The last volution is 5.8 mm in length and 2.1 mm in diameter with a form ratio of 2.8. Coiling in early two volutions is tight to moderate; the rest of the volutions are coiled slightly looser. Spirotheca in early two volutions?? is thin, 25-30 microns, its structure obscure; coarse alveolar keriotheca observed in two outer volutions where spirotheca is 120-140 microns thick. Septal flutings are irregular and widely spaced. Septae are strong and narrowly fluted throughout their length, fluting reaches almost the entire chamber's height and increases toward the polar ends. Phrenotheca are rare and observed only in the final volution. The tunnel is very narrow in early volutions and narrow elsewhere. Very small chomata is observed only on proloculus and first volution. Axial fillings are quite strong in the polar ends of the early four volutions.

Remarks. The described species possesses many features that separate it from the rest of Perigondwania. It has a smaller test and proloculus, tight coiling in early volutions, narrow tunnel and strong axial fillings. Because of limited material this species cannot be described as new, especially because of the small proloculus and tight coiling that occurs in the early volutions. This may represent microspheric reproductive generations of other known species or other species described in this study.

Stratigraphic range. Khan Formation, samples R-43, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalmard area, eastern-central Iran, Rahdar sections.

Genus NEODUTKEVITCHIA, new genus

v. 1993 Pseudofusulina Dunbar and Skinner, 1931; Leven, p. 162 (partim)

Type of genus. Neodutkevitchia snyderi Davydov and Arefifard new species, latest Sakmarian-early Artinskian, Rahdar section, Kalmard area, East-Central Iran.

Diagnosis. Large, subcylindrical to inflated fusiform test with large proloculus and loose coiling, strongly and deeply fluted septa, well-developed phrenotheca, lower cuniculi in the final volution.

Description. Test is large to very large in size, usually exceeds 7-8 mm, but sometimes can be slightly smaller in length. Its shape varies from subcylindrical and cylindrical to inflated-fusiform. Proloculus is large to very large, its outside diameter usually exceeds 200 microns. The coiling is loose, especially starting from third-fourth volutions, early volutions coiled slightly tighter. The spirotheca is thick with coarse alveolar keriotheca and smooth and thin dark tectum. Septae are strongly, deeply and irregularly fluted throughout the development of the test. In early volutions septae are fluted more regularly than in late volutions. Well-developed phrenotheca are present in the outer 1-2 volutions. Lower cuniculi are observed in final volution. Axial fillings are well developed only in early volutions where septal fluting is regular. On some species axial fillings might be weakly developed or absent. Chomata are absent.

Other species. Neodutkevitchia tezakensis (Leven 1997), Neodutkevitchia curteus (Leven 1993), Neodutkevitchia psharti (Leven 1993), Neodutkevitchia insignis (Leven 1993), Neodutkevitchia granuliformis (Leven 1993), Neodutkevitchia memoralis (Leven 1993), Neodutkevitchia neglectens (Leven 1993)

Neodutkevitchia licis (Leven 1993), Neodutkevitchia tumidiscula (Leven 1993), Neodutkevitchia vulgara (Leven 1993), Neodutkevitchia curta (Leven 1993), from Dangikalon Formation of Central Pamir; Neodutkevitchia spinosai, new genus and species, Neodutkevitchia partoazari, new genus and species, Neodutkevitchia complicata, new genus and species, Neodutkevitchia sp. 1 from Khan Formation in the Kalmard area of Central-Eastern Iran. Because of the transitional character of morphologies between Perigondwania and Neodutkevitchia, this genus included: Neodutkevitchia? curteum (Leven 1993), N.? gravis (Leven 1993), and N.? perrara (Leven 1993).

Etymology. The name of the genus Neodutkevitchia of Peri-Gondwanan affinity came from homeomorphic genus Dutkevitchia that is Tethyan affinity that strongly resemble each other.

Remarks. Like Perigondwania, the genus Neodutkevitchia distributed in Peri-Gondwana has also been described as Pseudofusulina (Leven 1993, see synonymy). However, it is different from Pseudofusulina in several important features such as loose coiling, a large proloculus, a well-developed phrenotheca and presence of cuniculi in final volution. Neodutkevitchia is very similar to Dutkevitchia from the late Gzhelian-Sakmarian of Tethys (Leven and Scherbovich 1978) in test size and shape outline, in character of septal fluting, presence of phrenotheca, a lower cuniculi in the final volution and especially in having a large proloculus and loose coiling that separate Neodutkevitchia as well as Dutkevitchia from the rest of the Schwagerinidae genera (Figure 9, Figure 10). The most notable contrast between these two genera is that Dutkevitchia possess strong rugosity of tectum that is lacking in Neodutkevitchia. Though genera occur in two different non-overlapped geographic areas, they partially overlap stratigraphically. Again, as in the case with Shagonella and Perigondwania, the strong homeomorphism can be noted between Dutkevitchia and Neodutkevitchia. However, tendencies in evolution of Neodutkevitchia seem somewhat different from what is known in Dutkevitchia (Davydov 1988). In general, however, evolution within the lineage Perigondwania-Neodutkevitchia is quite similar to the evolution within the lineage of Shagonella-Dutkevitchia. Increases of strong and chaotic septal fluting in development Shagonella give rise to genus Dutkevitchia. There is an opposite tendency in the development of septal fluting where it has become more and more regular to give rise to genus Ruzhenzevites (Davydov 1986, 1988). Similarly, two groups that most likely derived from Perigondwania can be separated among Neodutkevitchia. The first one, having irregular septal fluting, represents Neodutkevitchia itself. The second group that is unfortunately limited in our material seems to represents a tendency toward increasing more regular septal fluting. Unfortunately, our material on this group is limited. Typically it is included in Neodutkevitchia.

Stratigraphic range. Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Central Pamir, Central and Southern Afghanistan and the Kalmard area in Central-Eastern Iran.

Neodutkevitchia psharti (Leven, 1993)
Figure 7.3-7.5

v. 1993 Pseudofusulina psharti Leven, p. 166, pl. 3, fig.7, pl. 4, figs. 1-4.

Material. Nine axial and six paraxial sections.

Description. Test is large in size, elongate-fusiform with bluntly rounded poles. First volution is fusiform. Coiling is moderate to loose after tight inner 2-3 volutions. Proloculus is spherical, medium to large in size, with an outside diameter of 170-250 microns. Specimens of 4.5-6 volutions are 7.5-9 mm in length and 1.6-2.4 mm in diameter, giving form ratios of 3.4-4.6. First volution is 0.5-0.8 mm long and 0.2-0.3 wide with a form ratio of 2-2.3. The length and diameter of the fourth volution are 3.6-5.2 mm and 1.2-1.6 mm with form ratios of 2.6-4.6. Spirotheca is thick and composed of thick, coarse alveolar keriotheca and thin and smooth, dark tectum. The thickness of spirotheca in first, fourth and last volutions are 20-30, 60-70 and 70-120, respectively. Septae are thin, around 20-40 microns. They are strongly, narrowly and irregularly fluted throughout. Flutings start from early volutions and extend more than half of the chamber heights. Well-developed phrenotheca present in the outer 1-2 volutions. Chomata are absent. Well-developed axial fillings occur in early 2-3 volutions but are lacking in the rest of the volutions.

Remarks. Specimens from the Kalmard area differ from those in Central Pamir in slightly tighter coiling.

Stratigraphic range. Bed 6, Dangikalon Fm., Central Pamir; Khan Formation samples R-49-50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Rahdar section in Kalmard area, East-Central Iran.

Neodutkevitchia spinosai, new species
Figure 8.1-8.4

Holotype. SUI 103045. Axial section; sample M-49B-10, Madbeiki section, Khan Formation, unit 15, 135.5 m above the base of the sections, Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Five axial and three paraxial sections.

Description. Test is large, subcylindrical to fusiform with bluntly pointed poles. It is loosely coiled but early 3-4 volutions are fairly tighter. The first volution is ellipsoidal. Mature test of 4.5-5.5 volutions are 7.3-9.6 mm long and 2.2-2.5 mm wide, giving form ratios of 3.3-3.8. The first volution is 0.4-0.8 mm in length and 0.3-0.4 mm in diameter with form ratios of 1.5-2.1. The length and diameter of the fourth volutions are 5.3-6.6 mm and 1.4-2.2 mm with form ratios of 2.9-3.8. Proloculus is medium to large with an outside diameter of 150-280 microns. Spirotheca is thick with coarse alveolar keriotheca and smooth and thin dark tectum. It is thin in the early 2-3 volutions and gradually thickens throughout the growth. The thickness of spirotheca in first, fourth and last volutions are 20-30, 50-80 and 90-120 microns, respectively. Septae are thin to moderate in thickness, usually about 20-50 microns. Septae are intensely, narrowly and irregularly fluted in outer volutions but more regularly fluted in inner volutions. Well-developed phrenotheca are present in the outer 1-2 volutions. Chomata are absent. The tunnel is very narrow in early volutions, but gradually and slowly widens throughout the test development. Axial fillings well developed in the early two, tighter coiled volutions that separate them from the later volutions. Lower cuniculi are observed only in the final volution.

Etymology. The species is named in honor of Prof. Claude Spinosa, a well-known Permian ammonoid worker, our good colleague, and First Co-Director of the Permian Research Institute at Boise State University.

Remarks. Neodutkevichia spinosai resembles Neodutkevichia insignis (Leven 1993) in general outline, and character of coiling throughout the growth, but differs from the latter in stronger septal fluting and particularly in the outer volutions and in narrow tunnels. Cuniculi are observed in N. spinosai, but it is not clear if they are present in N. insignis.

Stratigraphic range. Khan Formation samples M-49B, R-43,49-50; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Madbeiki and Rahdar sections in the Kalmard area, East-Central Iran.

Neodutkevitchia insignis (Leven, 1993)
Figure 8.5

v. 1993 Pseudofusulina insignis Leven, p. 167, pl. 4, figs. 6-8.

Material. Two axial and two oblique sections.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation, Rahdar section, samples R-43, R-50, R-51, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Rahdar section in the Kalmard area, East-Central Iran.

Neodutkevitchia snyderi, new species
Figure 8.9-8.10

Holotype. SUI 103054. Axial section; sample R-48-1, Rahdar section, Khan Formation, unit 7, 133 m above the base of the sections, the Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. Three axial and two paraxial sections.

Description. The test is of moderate size, fusiform to inflated-fusiform with narrowly rounded poles. The first volution is ellipsoidal to inflated-fusiform. Coiling is relatively loose, but slightly tighter in the early two volutions. Proloculus is spherical to sub-spherical, very large, with an outside diameter of 300-420 microns. Specimens of 4-4.5 volutions are 6.7-6.9 mm in length and 2.1-2.4 mm in diameter, giving form ratios of 2.9-3.2. The first volution is 1.1-1.2 mm long and 0.6-0.7 wide with a form ratio of 1.6-1.8. Spirotheca is thick and composed of coarse alveolar keriotheca and smooth and thin dark tectum. The thickness of spirotheca in first, fourth and last volutions are 25-35, 50-60 and 90-115 microns, respectively. Septae are thin, usually about 20-25 microns. They are strongly, narrowly and very irregularly fluted throughout the length of the volutions. Septal fluting is deep and regular in the early two volutions. Folds are sharp and quite irregular in shape in three outer volutions, but high and sub-square in the early two volutions. Well-developed phrenotheca are present in the outer two volutions. Chomata are lacking. Axial fillings are well developed in early two volutions. The tunnel is very narrow and low throughout the growth. Lower cuniculi are observed in two outer volutions.

Etymology. This species is named in honor of Prof. W.S. Snyder, Co-Director of Permian Research Institute, at Boise State University. Prof. Snyder is a well-recognized stratigrapher, paleontologist and sedimentologist who researches the Upper Paleozoic globally.

Remarks. Characteristic features of this species are an inflated fusiform test with a large proloculus and loose coiling and rather irregular septal fluting in outer volutions.

Stratigraphic range. Khan Formation samples H-62, R-48; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Halvan and Rahdar sections in the Kalmard area, East-Central Iran.

Neodutkevitchia partoazari, new species
Figure 8.12

v. 1993 Pseudofusulina curta Leven (partim), p. 173, pl. 7, fig. 14 (only)

Holotype. SUI 103054. Axial section; sample H-62-3, Halvan section, Khan Formation, unit 9, 145 m above the base of the sections, the Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. One axial and one oblique section in our collection and one axial section from Leven (1993).

Description. The test is moderate in size, inflated fusiform to sub-rhomboidal with narrowly rounded to sharply pointed poles. Coiling is loose and uniformly expended from the first volution, where it is moderate in height. The first volution is ellipsoidal to sub-rhomboidal. Mature test of 4-5 volutions is 5.0-5.6 mm in length and 1.7-2.0 mm in diameter, giving a form ratio of 2.8-3.0. The first volution is 0.7-1.1 mm in length and 0.4-0.6 in diameter with form ratios of 1.7-1.8. Proloculus is large with an outside diameter of 220-320 microns. Spirotheca is thick, up to 110 microns, with coarse alveolar keriotheca and smooth and thin dark tectum. The thickness gradually increased throughout the growth of test. Septae are thin, usually about 20-30 microns. They are deeply, strongly and regularly fluted throughout the length of shell and form high and nearly sub-square arches that are thickened at the top. Chomata are lacking. Axial fillings are weakly developed and present in the early 2-3 volutions. Rare phrenotheca observed in two outer volutions. Presence of cuniculi was not documented.

Etymology. This species is named after Iranian geologist and paleontologist Dr. H. Partoazar from Geological Survey of Iran, who studied the Permian in Iran.

Remarks. Neodutkevichia partoazari are similar to Neodutkevichia snyderi, a new species, in many respects but have a smaller and sub-rhomboidal test, slightly tighter and more uniform coiling, and more regular septal fluting.

Stratigraphic range. Bed 6, Dangikalon Formation; Khan Formation, Halvan section, sample H-62; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Kalaktash area, Central Pamir, Tadzhikistan; Halvan section in Kalmard area, East-Central Iran.

Neodutkevitchia complicata new species
Figure 8.13

Holotype. SUI 103057. Axial section; sample H-62-8, Halvan section, Khan Formation, unit 9, 145 meters above the base of the sections, Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. 1 axial and one oblique sections.

Description. Test is large in size, subcylindrical with bluntly rounded to slightly pointed poles, loosely coiled. First volution is subspherical. Proloculus is spherical and large with outside diameter of 320 microns. Mature test of 3-3.5 volutions is 8.8-9.0 mm long and 1.9-2.1 mm wide with form ratio 4.3-4.6. Spirotheca is thin (20-25 microns) in first volution, gradually and uniformly thickens up to 100 microns in final volution. Septae are thin, 20-25 microns, closely spaced, very intensely, highly and very irregularly fluted throughout the length of shell. Closed chamberlets extendsto tops of chambers in all volutions. Chomata are lacking. Tunnel is very narrow and very low throughout. Very weak axial fillings are present only in first volution. Rare phrenotheca present in final volution only.

Etymology. Complicata (latin) - complex, and is given in respect of complex character of septal fluting in this species.

Remarks. Neodutkevichia complicata differs from all other Neodutkevichia in having a subcylindrical test outline, loose and uniform coiling, as well as a strong and very irregular septal fluting.

Stratigraphic range. Khan Formation samples H-62; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Halvan section in Kalmard area, East-Central Iran.

Neodutkevitchia sp. 1
Figure 8.11

Holotype. SUI 103055. Axial section; sample H-62-1, Halvan section, Khan Formation, unit 9, 145 meters above the base of the sections, Kalmard area, east-central Iran, Permian, Cisuralian, latest Sakmarian-early Artinskian.

Material. One axial and one sagittal section.

Description. Test is moderate in size, sub-rhomboidal with narrowly rounded to slightly pointed poles, loosely and uniformly coiled. First volution is subspherical. Proloculus is spherical and large with an outside diameter of 260 microns. Mature test of 4.5-5 volutions is 5.8 mm long and 2.2 mm wide with a form ratio of 2.6. Spirotheca is moderate in thickness, 50 microns the first volution, and very gradually and uniformly thickens up to 80-90 microns in the final volution. Septae are thin, 20–25 microns, closely spaced, very intensely, highly and relatively regularly fluted throughout the length of the shell. Closed chamberlets extend nearly to the tops of the chambers in all volutions. The tunnel is very narrow and low throughout. Axial fillings and chomata are lacking. No phrenotheca is observed in the studied specimen.

Remarks. Neodutkevichia sp. 1 closely resembles Neodutkevichia partoazari in sub-rhomboidal test outline, loose and uniform coiling and strong septal fluting, but differs in less regular septal fluting, lacking axial fillings and phrenotheca. It cannot be excluded that Neodutkevichia sp. 1 might fall within the variation among the population of N. partoazari, but limited material does not allow us to clarify this problem.

Stratigraphic range Khan Formation samples H-62; Permian, Cisuralian, latest Sakmarian-early Artinskian.

Geographic occurrence. Halvan section in the Kalmard area, East-Central Iran.

 

Next Section

Persian Permian Fusulinids
Plain-Language & Multilingual  Abstracts | Abstract | Introduction and Previous Work
Geologic Setting | Stratigraphy and Sedimentology | Systematic Paleontology 
Correlation and Biostratigraphy of the Khan Formation with Correlative Peri-Gondwana Deposits
Age of Peri-Gondwanan Eoparafusulina and Perigondwania-Neodutkevitchia Assemblages
Paleobiogeographic and Paleotectonic Implications of the Perigondwania-Neodutkevitchia Assemblages from Khan Formation | Conclusions | Acknowledgements | References
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