Salpingoporella Pia

Schlagintweit, Felix, Rashidi, Koorosh & Kivani, Fahime, 2016, On The Occurrence Of Salpingoporella Pasmanica Radoičić, 2002, (Dasycladales) From The Late Maastrichtian Of The Zagros Zone, Sw Iran, Acta Palaeontologica Romaniae 12 (1), pp. 33-42 : 34-36

Genus Salpingoporella Pia , in Trauth, 1918 Salpingoporella pasmanica Radoičić

Figs. 4 pars, 5–6

*2002 Salpingoporella pasmanica n. sp. – Radoičić, p. 84, pl. 1, figs. 1-11, 13a.

2006 Salpingoporella pasmanica Radoičić – Carras et al., p. 482, pl. 7, fig. 5-10.

2010 Salpingoporella dinarica Radoičić – Afghah, Fig. 5.1.1 .

2012 Salpingoporella dinarica Radoičić – Afghah and Farhoudi, pl. 1, fig. 1.

2014 Salpingoporella dinarica Radoičić – Afghah and Yaghmour, pl. 2, fig. 1.

2016 Salpingoporella turgida (Radoičić) – Afghah, fig. 5f.

Description: The thallus is comparatively small, cylindrical, often displaying a bended habitus. It consists of fine- to medium-grained mosaic calcite. Outer surface shows the cavities of the laterals, whereas the inner surface is even and smooth. The central cavity comprises about 40 to 60 % of the total diameter. The laterals are typically phloiophorous, uncompressed (= circular transverse sections), set perpendicular to the axis, and are arranged in alternating whorls (forming quincunxes). From longitudinal sections it can be deduced that the laterals are mutually touching on the outer surface. Based on comparatively poor specimens, the original diagnosis calls for the cortical pattern to be subrectangular. In our specimens, on the other hand, the laterals are circular, occasionally subcircular in cortical section.

Dimensions (mm):

Thallus diameter (D): 0.18-0.35 ( Radoičić, 2002: 0.08- 0.144 mm)

Inner diameter of thallus (d): 0.08-0.2 ( Radoičić, 2002: 0.032 -0.064 mm)

d/D: 0.4-0.6 ( Carras et al., 2006: 0.36-50)

Verticil spacing (h): 0.05-0.075 ( Radoičić, 2002: 0.032 - 0.035 mm)

Number of laterals per verticil (w): 10-15 ( Radoičić, 2002: 6-8).

Remarks: Except the overall dimensions, the specimens from the Maastrichtian of Iran, match the principal thallus organization of S. pasmanica described by Radoičić (2002) from Middle? Campanian of Croatia. The larger dimensions might be explained by different environmental settings, allodapic (transported; sorting) specimens in hemipelagic slope sediments at the type-locality, against inner platform lagoonal setting in the Maastrichtian Tarbur Formation. Moreover, from the illustrations provided by Radoičić (2002) one might suspect that the original description was based on rather poor material. This can be inferred from just eleven illustrated sections and a rather low range of biometric data. With the two known occurrences in the Campanian of Croatia, Maastrichtian of Iran (Zagros Zone), and Campanian of Lybia (unpublished, pers. comm. R. Radoičić) S. pasmanica might potentially be restricted to the former southern Neotethyan margin. A final conclusions of course will need more data to come.

Comparisons: In the Iranian literature, S. pasmanica was confused with the lower Cretaceous S. dinarica Radoičić and also with Salpingoporella (= Morelletpora ) turgida Radoičić. S. dinarica , reported from the Berriasian- Albian, is characterized by densely set verticils composed of a rather low number of laterals (4-10), and a skeleton composed of hyaline yellowish calcite (see Carras et al., 2006). Due to these characteristics, S. dinarica is clearly different from the Maastrichtian specimens of the Zagros Zone. Salpingoporella turgida Radoičić , another Lower Cretaceous taxon with which S. pasmanica has been confounded, was transferred to the genus Morelletpora ( Bucur et al., 2016, for details). With its articulated thallus of barrel-shaped articles and distinctly larger size, M. turgida can easily be distinguished from S. pasmanica .

On the occurrence of Salpingoporella pasmanica Radoičić, 2002 , ( Dasycladales ) from the Late Maastrichtian of the Zagros Zone, SW Iran

Microfacies and associations: S. pasmanica is observed in foraminiferan-dasycladalean wackestones to packstones, referring to a soft substrate and very low water energy in a shallow protected lagoon. This can be inferred from the association of agglutinated conical foraminifera ( Orbitolinidae indet., Gyroconulina , Dictyoconella ), miliolids (among complex taxa as Broeckina sp. , Spirolina sp. , and others), and dasycladalean algae. Except the lack of alveolinids, and the presence of rudists, this association can palaeoecologically be compared with equivalent associations of the Paleogene (e.g., Vecchio and Hottinger, 2007, fig. 5) ( Fig. 7 ), e.g., the socalled “ Spirolina facies” of the Mediterranean area (e.g., Sartoni and Crescenti, 1962; Radoičić, 1995; Fleury, 1997; Barattolo et al., 2000). As a depth trend, the Mandegan section displays a shallowing upwards sedimentary succession with the remarked association occurring in the upper part. Amongst the Dasycladales we note the occurrence of Pseudocymopolia anadyomenea (Elliott) ( Fig. 8 A-B), Pseudocymopolia ? sp. ( Fig. 8C ), and other so far undetermined taxa. It is worth mentioning here that usually representatives of Pseudocymopolia are reported from more agitated external platform environments ( Bucur, 1993; Barattolo & D´Andrea, 1990). The foraminiferan association is diverse including (in alphabetical order) Antalyna korayi Farinacci & Köylüoglu , Broeckina sp. , Cuneolina sp. , Cuvillerinella cf. salentina Papetti & Tedeschi, Dicyclina cf. schlumbergeri Munier- Chalmas, Dictyoconella complanata Henson , Dictyoconella minima Henson , Elazigella ? sp., Fallotia aff. jacquoti Douvillé , Gyroconulina columellifera Schroeder & Darmoian , Loftusia harrisoni Cox , Loftusia coxi Henson , Loftusia morgani Douvillé , Mississippina? binkhorsti (Reuss) , Minouxia sp. , Nezzazatinella ? cf. picardi (Henson), Neobalkhania bignoti Cherchi, Radoičić & Schroeder , Elphidiella ? cretaceus (Pérébaskine) [= Rotalia cf. skorensis in Pirbalouti and Abyat, 2013, Pl. 1, Fig. 9 ), Omphalocyclus macroporus (Lamarck) , Orbitolinidae indet., Pyrgo ? sp., Spirolina sp. , Valvulina ? sp. 1 Sirel. It must be stressed, that not all the above listed taxa are co-occurring in the same sample. Some of the biostratigraphic important larger benthic foraminifera observed in the Tarbur Formation of the Mandegan section are shown in Figure 9 .

Stratigraphy: Based on larger benthic foraminifera [e.g., Loftusia ssp., Siderolites calcitrapoides Lamarck , Gyroconulina columellifera Schroeder & Darmoian , Omphalocyclus macroporus (Lamarck) ( Fig. 9 )], the Tarbur Formation of the Mandegan section is Maastrichtian in age ( Schlagintweit et al., 2016, in press). Neobalkhania bignoti was originally described by Cherchi et al. (1991) from the Late Maastrichtian of Croatia. Besides, they also noted its occurrence in time-equivalent strata from Greece, leading Cherchi et al. (1991, p. 288) to conclude that N. bignoti represents “an excellent marker of this time interval” (see also Fleury, 2014, Fig. 3 ). In the Mandegan section, the first dasycladalean algae appear almost together with some larger benthic foraminifera such as Loftusia ssp., G. columellifera , and N. bignoti in the upper part of unit 1. In conclusion, a Late Maastrichtian age for the samples with Salpingoporella pasmanica is most likely. The occurrence of Pseudocymopolia anadyomenea (Elliott) is also an indication for a Maastrichti- an age ( Elliott, 1959, 1970; Barattolo, 2002; Rashidi et al., 2013).

The inventory and stratigraphy of Late Cretaceous (Turonian-Maastrichtian) Salpingoporella species is compiled in Figure 10 using data of Carras et al. (2006) with additional species Salpingoporella nicolacarrasi described later by Radoičić and Conrad (2012). Following the assumption of Carras et al. (2006) that Salpingoporella represents an exclusively Mesozoic taxon, the occurrence of S. pasmanica in the Late Maastrichtian of Iran represents the youngest representative of the genus. It is worth mentioning that this view is not unambiguous, with an extended range until the Paleocene-Eocene boundary (e.g., Barattolo, 2002).

Figures

Fig. 4 Microfacies of Late Maastrichtian Tarbur Formation. a Bioclastic wacke-/packstone with large benthic foraminifer Loftusia sp. and dasycladale Salpingoporella pasmanica Radoičić (transverse section, arrow and detailed view). Thinsection Rt 177-1. Scale bars: 1.0 mm and 0.3 mm (detail, right below). b Bioclastic wacke-/packstone with large benthic foraminifera (Dicyclina? sp.), and dasycladalean algae Salpingoporella pasmanica Radoičić (arrow) and Salpingoporella? sp. with tilted laterals.

Fig. 5 Salpingoporella pasmanica Radoičić, Late Maastrichtian Tarbur Formation of Mandegan section, Zagros Zone, SW Iran. a Longitudinal section. b-d, m Longitudinal-tangential sections. e-f Oblique sections. g-l, n, o Transverse sections, partly slightly oblique. Thin-sections: Rt 89-2B (a-d), Rt 79-2 (e-f), SNSB-BSPG 2016 III-6 (g-o).

Fig. 7 Schematic distribution of larger benthic foraminifera in the Eocene Trentinara Formation of Italy (based on Vecchio and Hottinger, 2007, fig. 5), and the Maastrichtian Tarbur Formation (examples; without scale). 1 Rotaliids (e.g., Rotorbinella), 2 Siderolites, 3 Orbitoides, 4 Loftusia, 5-6 Orbitolinidae (5: Dictyoconella minima), 7 Gyroconulina, 8 Rhapydionidae, 9 Spirolina, 10 Pyrgo?, 11 Broeckina. 5-7: Agglutinated conical foraminifera, 8-11: Porcelaneous foraminifera. Note the basinal facies corresponds to the Gurpi Formation.

Fig. 8 Some dasycladales associated with Salpingoporella pasmanica Radoičić. a-b Pseudocymopolia anadyomenea (Elliott), thin-sections BSPG IX 2016-8 (Rt 89), Rt 67-3. c Pseudocymopolia? sp., thin-section Rt 72. Scale bars 1.0 mm.

Fig. 9 Some biostratigraphic importance larger benthic foraminifera from the Maastrichtian Tarbur Formation of the Mandegan section. a Omphalocyclus macroporus (Lamarck), thin-section RT 65. b-c Neobalkhania bignoti Cherchi, Radoičić & Schroeder, thin-sections Rt 79-2, SNSB-BSPG 2016 III-6 (Rt 79). d Orbitoides media d´Archiac, thinsection RT 30. e Gyroconulina columellifera Schroeder & Darmoian, thin-section Rt 113. f Loftusia sp., thin-section Rt 113. g Siderolites cf. calcitrapoides Lamarck, thin-section Rt 36. Scale bars = 1.0 mm, except b-c, e = 0.5 mm.

Fig. 3 Vertical distribution (total range) of selected taxa of larger benthic foraminifera and dasycladalean algae in the Tarbur Formation of the Mandegan section.

Fig. 10 Stratigraphic distribution of Late Cretaceous (here: Turonian– Maastrichtian) Salpingoporella species (redrawn from Carras et al., 2006; added the data for S. nicolacarassi from Radoičić and Conrad, 2012).