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Rhynchonellide brachiopods from the Marhouma Formation, Upper Devonian (Famennian), Saoura Valley, Algeria (see Fig. 1). (a-j) Novaplatirostrum sp.: (a-e) MUA/1024/027: complete specimen in ventral, dorsal, lateral, posterior and anterior views; (f-j) MUA/1094/028: complete specimen in ventral, dorsal, lateral, posterior and anterior views. (k-o) Pugnaria sp., MUA/1094/029: complete specimen in ventral, dorsal, lateral, posterior and anterior views. (p-x) Phacoiderhynchus aff. antiatlasicus Sartenaer, 2000: (p-s) MUA/1094/030: almost complete specimen in ventral, dorsal, lateral and posterior views; (t-x) MUA/1094/031: incomplete specimen in ventral, dorsal, lateral, posterior and anterior views. Scale bars: 5 mm.
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In the Saoura Valley (Ougarta Basin, Saharan Algeria), the lower–upper Famennian part of the essentially shally Marhouma Formation is characterized by deep-water facies and includes horizons rich in ammonoids (goniatites and clymeniids) and blind to eye-reduced phacopide trilobites. They are also rich in small-sized and smooth rhynchonellide brachi...
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In order to locate the Devonian–Carboniferous boundary in the Saoura Valley (Ougarta Basin), we have only studied the Ouarourout section in its northern part, and the Béchir and Tamtert-Zereg sections in its southern part.
The identification of macrofaunas was made by C. Crônier for the trilobites, D. Brice and B. Mottequin for the Devonian brachio...
Citations
... However their stratigraphic range is not clearly defined and the correlations of these assemblages with the Moroccan biozonations have not been precisely established. Although since several years, the systematic and biostratigraphic revision of Devonian invertebrates from the Saoura Valley of Algeria have received a renewed interest (e.g., for brachiopods: Mottequin et al., 2015; for trilobites: Crônier et al., 2013, Feist et al., 2016 for ammonoids: , the ammonoids still remained scarcely described and not precisely sampled. ...
... Our material originates from the 'Argiles de Marhouma' Formation (Fig. 3), which is primarily characterized by fine-grained turbidite successions, interspersed with 'griotte' limestones bearing a pelagic fauna and showing a wide variety of fossil traces (Bendella and Ouali Mehadji, 2015). According to ammonoid, brachiopod, trilobite, conodont, and ostracod assemblages (Petter, 1959(Petter, , 1960Casier, 1983;Malti, 2012;Crônier et al., 2013;Mottequin et al., 2015;Abbache et al., 2019), this formation contains Frasnian to Famennian (Late Devonian) deposits. This Colonne stratigraphique et vues de la section de Ouarourout près de Béni-Abbès (vallée de la Saoura, Algérie). ...
... • the unit 'M2a' comprises silty shales with numerous rhynchonellids (Evanidisinurostrum saouraense, Sphaeridiorhynchus; possibly from the early Famennian, see Mottequin et al., 2015) in thin calcareous lenses rich in horizontal burrows; • and the unit 'M2b' consists of alternating shales and 'griotte' limestones containing the Famennian conodont Palmatolepis minuta, as well as the middle Famennian trilobite Trimerocephalus caecus and rhynchonellid Leptoterorhynchus. ...
In North Africa, the ammonoids constitute an important part of the Devonian marine macro-invertebrates. New material has been recently collected in the ‘Argiles de Marhouma’ Formation from several sections located near Béni-Abbès in the Saoura Valley (Ougarta Mountains, Algerian Sahara). Red nodular limestones (i.e., ‘griotte’ facies) characterize this formation rich in ammonoids. The assemblages from the Ouarourout section are composed of Goniatitida and Clymeniida constituting 30 species and 19 genera belonging to 11 families, with Cyrtoclymenia, Erfoudites, Kosmoclymenia, Planitornoceras, Platyclymenia, and Prionoceras, as the most abundant genera. The taxonomic comparison and the biostratigraphic correlations are made by considering the assemblages recorded in the Anti-Atlas of Morocco, which are very close to those observed in Algeria. In the Ouarourout area, the ‘Argiles de Marhouma’ Formation contains middle and late Famennian ammonoid assemblages and three biostratigraphic intervals can be identified: Planitornoceras, Platyclymenia and Medioclymenia.
... 4 around the Devonian-Carboniferous boundary are Tietze (1870), Paeckelmann (1913Paeckelmann ( , 1930Paeckelmann ( , 1931, Schmidt (1924), Grüneberg (1925), Gallwitz (1932), Weyer (1972Weyer ( , 1979, Bartzsch and Weyer (1986), Becker (1988Becker ( , 1996, Bartzsch et al. (1998), Sartenaer (1997), Afanasjeva (2002) and Müller (2004). Comparatively few similar studies about such rare aphotic Famennian-Hastarian Brachiopoda were published in other countries: Poland (Biernat, 1983(Biernat, , 1988Racki, 1986a, 1986b;Sartenaer, 1998a;Halamski and Baliński, 2009), Czech Republic (Havlíček, 1979), Russia (Rozman, 1962), Algeria (Mottequin et al., 2015a), Morocco (Sartenaer, 1998a(Sartenaer, , 1998b(Sartenaer, , 1999(Sartenaer, , 2000 and China (Sartenaer and Xu, 1990). ...
... 290) admit that also ammonoids of the Clymenia-"Stufe" had been found in their "bed L". The records from Northern Africa are older: Mottequin et al. (2015a) (Algeria, boundary of Platyclymenia-/Clymenia-"Stufe"), Sartenaer (1998b) (Morocco, Clymenia-"Stufe"). The precise age of the Czech type materials from Moravia (Hady Limestone near Brno, "do V-VI") remains unclear without more accurate locality data, e.g., as used by Chlupáč (1966, tab. ...
... fibrosissimum as the predominant species. These rhynchonellides belong to the superfamily Pugnacoidea, of which representatives rank among the most common elements of Devonian-Carboniferous dysaerobic environments (e.g., Bowen et al., 1974;Biernat and Racki, 1986a;Racki, 1989;Alexander, 1994;Sartenaer et al., 1998;Mottequin and Legrand-Blain, 2010;Mottequin et al., 2015a). Palaeobiological implications of the co-occurrence of uniplicate and unisulcate rhynchonellides in Polish contemporaneous succession was discussed by Halamski and Baliński (2009). ...
Upper Famennian-Tournaisian (Hastarian) brachiopods from the deep-water, mixed siliciclastic-carbonate Gleitsch Formation (Breternitz and Pfaffenberg members) of southeastern Thuringia (mainly from the Saalfeld area, Germany) are described systematically. A new Tournaisian rhynchonellide genus (Thuringorhynchus gen. nov.) and four new Tournaisian species are described (Productina saalfeldensis sp. nov., Thuringorhynchus pseudoequitans gen. et sp. nov., Cleiothyridina pfaffenbergensis sp. nov., and Crassumbo germanicus sp. nov.). Moreover, the lectotype of “Lingularia” straeleni (Demanet, 1934), from the Tournaisian of Belgium, is selected. Prior the Hangenberg Crisis, the brachiopod assemblage (10 species) of the Breternitz Member (upper and uppermost Famennian) is strongly dominated by species belonging to smooth to poorly ornamented rhynchonellide genera (Hadyrhyncha, Novaplatirostrum, Rozmanaria, and rozmanariid? gen. indet.) notably reported from Laurussia and the northern margin of Gondwana. The onset of the Hangenberg Crisis is marked by an anoxic black shale horizon at the top of the Breternitz Member followed by the siltstones and turbiditic sandstones of the Obernitz Member; both horizons did not yield brachiopods.
A completely changed, more diverse brachiopod assemblage (15 species) existed in the Pfaffenberg Member (Tournaisian, lower Hastarian), which also included a basal 20 cm “topmost Famennian” (according to the current, soon abandoned definition of the Carboniferous base using Siphonodella sulcata as criterion), but clearly dated as upper Protognathodus kockeli Zone). Small-sized productidines (Productina) and spiriferides (Crassumbo, Texathyris?) dominate; a probable complete turnover is recorded among the Rhynchonellida (Thuringorhynchus). The rapid recovery after the drastic Hangenberg extinction event includes species belonging to pre-existing genera and to new ones.
... These localties expose the 'Argiles de Marhouma' (= Marhouma Formation), which is Frasnian to Famen- nian in age on the basis of ammonoids (Petter 1959(Petter , 1960(Petter ), trilobites (cr?nier et al. 2013) and brachiopods ( Mottequin et al. 2015). The Marhouma Formation is composed of grey or red shales with grey or red lime- stone nodules with abundant ammonoids. ...
The late Famennian ammonoid succession in the Saoura Valley of western Algeria is characterized by rather clearly separated assemblages. From bottom to top, four distinct assemblages can be defined, the Gonioclymenia, Medioclymenia, Cymaclymenia lambidia and Wocklumeria assemblage. The ammonoids show close relationships with time equivalent occurrences of the Anti-Atlas of Morocco. The following new species are described: Mimimitoceras callumbilicum, Muessenbiaergia ouarouroutensis, Muessenbiaergia beniabbesensis, Linguaclymenia phillipsi, Medioclymenia saourensis, Cyrtoclymenia nodifera and Biloclymenia australis.
... Close relationships between Western and Eastern Europe and North Africa were also recognized for Middle and Upper Devonian brachiopod assemblages and might indicate the close proximity between Laurussia and Gondwana (e.g. Halamski and Baliński, 2013;Mottequin et al., 2015a). Generic affinities, especially among the productides (e.g. ...
Late Viséan brachiopods from the eastern Tafilalt (Morocco), and more precisely from the area comprised between the Jebel Begaa to the southwest, and Gara El Itima to the northeast (close to the Algerian border), are described systematically for the first time. Despite the limited material available, 18 species belonging to 17 genera have been recognized within the limestone beds of the Merdani and Zrigat formations, in which the productides (Productidina) and spiriferides are the most diverse. Representatives of the subfamily Gigantoproductidinae, which are close, if not conspecific, to those present in contemporaneous rocks of the nearby Béchar Basin (Algeria), occur in the late Viséan Zrigat Formation. Additional research based on more abundant material is necessary to investigate thoroughly the relationships existing between the Béchar Basin and the Tafilalt, which may have been part of the former during the Carboniferous.
... In the Saoura Valley, the Marhouma Formation (e.g., Crônier et al., 2013; Mottequin et al., 2015) is subdivided into four members extending from the Frasnian up to the late Famennian. It is followed by the latest Famennian Ouarourout Formation. ...
... In the Ouarourout area, the Famennian V is identified only on the basis of the occurrence of Pugnaria sp. within the lower part the Member 4 (Mottequin et al., 2015). Nevertheless, in the Tamtert-Zereg area, the Gonioclymenia Zone is followed probably by the Wocklumeria Zone as indicated by the presence of numerous Cymaclymenia sp. ...
In order to locate the Devonian–Carboniferous boundary in the Saoura Valley (Ougarta Basin), we have only studied the Ouarourout section in its northern part, and the Béchir and Tamtert-Zereg sections in its southern part.
The identification of macrofaunas was made by C. Crônier for the trilobites, D. Brice and B. Mottequin for the Devonian brachiopods (rhynchonellides), D. Korn for the ammonoids, and M. Legrand-Blain for the early Tournaisian brachiopods. Concerning the microfaunas, L. Samar and C. Randon identified the palynomorphs and the conodonts, respectively.
In the Saoura Valley, the Marhouma Formation (e.g., Crônier et al., 2013; Mottequin et al., 2015) is subdivided into four members extending from the Frasnian up to the late Famennian. It is followed by the latest Famennian Ouarourout Formation. The latter is overlaid by the Tournaisian Ouled Bou-Hadid Formation.
This study is focused on the interval ranging from the Member 4 of the Marhouma Formation to the end of the Ouled Bou-Hadid Formation. The Member 4 consists of shales with some “griotte” levels, but also sandy and silty deposits of turbiditic origin. The latter are more developed than the “griottes” due to the sedimentary supply rate, which was higher than the increase of the relative sea level. The “griottes” are represented by thin levels, and sometimes only by nodules.
The Goniclymenia Zone, which has already been recognized in the upper part of the Member 3 of the Marhouma Formation, is also reported in the Member 4 in the Tamtert-Zereg and Béchir areas. In the Ouarourout area, the Famennian V is identified only on the basis of the occurrence of Pugnaria sp. within the lower part the Member 4 (Mottequin et al., 2015). Nevertheless, in the Tamtert-Zereg area, the Gonioclymenia Zone is followed probably by the Wocklumeria Zone as indicated by the presence of numerous Cymaclymenia sp. associated to dwarf forms of Rabienops wedekindi, confirming a do VI age. Moreover, Petter (1960) already reported ammonoids of the Wocklumeria Zone from a shale layer underlying this level of “griotte” limestones. The dwarfism of these trilobites heralds their extinction, linked to the Hagenberg Event.
The turbiditic character of the deposits of the Member 4 predominates in the south-eastern part of the Saoura Valley and reflects a deepening phase of the basin. The last level of griotte limestones with Cymaclymenia sp. crops out only at Tamtert-Zereg and marks the end of the Marhouma Formation. This “griotte” level corresponds to a marine incursion in this area. At Ouarourout, the shales of the upper part of this member yielded late Famennian palynomorphs whereas in the Tamtert-Zereg section, the palynomorphs also include species that are typical of the D–C boundary.
From NW to SE, shales alternating with slumped sandstones succeeded the turbiditic deposits and belong to the Ouarourout Formation. They have always been interpreted as regression deposits in all the Saharan basins. In the Ouarourout area, Vallatusporites pusillites (Kedo) Dolby & Neves, Umbellasphaeridium saharicum Jardiné et al. and Umbellasphaeridium sp. have been recovered from the upper part of the Ouarourout Formation and indicate a late Famennian age. Therefore, we cannot affirm the existence of a sharp regression, because this assemblage of miospores and acritarchs already indicates a marine environment with continental influences. In this area, the transgression took place at the end of the latest Famennian and not at the base of the Tournaisian.
The early Tournaisian conformably lies on the latest Famennian only to the north of Ouarourout, whereas in some boreholes located northernmost of the Saoura Valley, an angular unconformity was detected between the Devonian and the Carboniferous strata. This unconformity is a proof of the Breton phase of the Variscan orogeny (Malti et al., 2008). The base of the Tournaisian is indicated by the appearance of a thin limestone bed (named here “Conrad level”), which is rich in reworked conodonts of the upper expensa Zone that are associated to other conodonts characteristic of the early Tournaisian sulcata Zone. The “Conrad level” is overlaid by clear shales that include a single occurrence of numerous Acutimoceras sp. and Gattendorfia sp. of the Gattendortfia Zone (or Zone VII). Conversely, in the contemporaneous Kahla Formation (Timimoun Basin), ammonoid occurrences belonging to the same zone are more numerous in shaly intercalations (Ebbighausen et al., 2004).
The Ouled Bou-Hadid Formation is notably characterized by thick red shale deposits, interrupted by two thin levels of limestones rich in basal Hastarian brachiopods (Pareyn, 1961; Malti et al., 2008). These deposits are capped by a thin limestone bed, which yields numerous late Hastarian brachiopods. Their thickness shows the importance of the basin filling phase, interrupted by some marine incursions during this period.
In the Saoura Valley, the D–C boundary is located in the upper part of the Member 4 of the Marhouma Formation in the Tamtert-Zereg area, whereas, in the Ouarourout area, this boundary has to be placed in the upper part of the Ouarourout Formation, 10 m below the “Conrad level”. We have thus identified a clear diachronism in this part of Ougarta Basin. Contrary to the previous workers, we have concluded that, during the D–C transition, the sea first invaded the south-eastern part of the basin and reached later its north-western part.
References
Crônier C., Malti F.Z., François A., Benyoucef M. & Brice D. (2013). First occurrence of a phacopid trilobite faunule from the Upper Devonian of Saoura Valley, Algeria and biodiversity fluctuations. Geological Magazine, 150: 10021021
Ebbighausen V., Bockwinkel J., Korn D. & Weyer D. (2004). Early Tournaisian ammonoids from Timimoun (Gourara, Algeria). Mitteilungen aus dem Museum für Naturkunde in Berlin Geowissenchaftliche Reihe, Band 7: 133-152
Malti, F.Z., Benhamou M., Mekahli L. & Benyoucef M. (2008). The development of the Carboniferous Ben-Zireg Zousfana Trough in the northern part of the Béchar Basin, Western Algeria: implications for its structural evolution, sequence stratigraphy and paleogeography. Geological Journal, 43: 1-24
Mottequin B., Malti F.Z., Benyoucef M., Crônier C., Samar L., Randon C. & Brice D. (2015). Famennian rhynchonellides (Brachiopoda) from deep-water facies of the Ougarta Basin (Saoura Valley, Algeria). Geological Magazine, doi: 10.1017/S0016756814000697
Pareyn C. (1961). Les Massifs Carbonifères du Sahara Sud-Oranais. Publications du Centre de Recherches Sahariennes (Editions du Centre National de la Recherche Scientifique, Paris), Série Géologie, 1: 1-326 (vol. 1), 1-324 (vol. 2)
Petter G. (1960). Clyménies du Sahara. Publications de la Carte géologique de l’Algérie (Paléontologie), 6: 1-58
... Among the spiriferids, the early Famennian is mostly characterized by the development of the Cyrtiopsinae that progressively supplanted the Cyrtospiriferinae. The genus Aulacella is sometimes a common element of the epibenthos within ammonoid facies from the Famennian of Morocco and Algeria (Webster et al. 2005;Mottequin et al. 2015), but also of the Famennian Annulata events beds, notably in Germany and Iran (Becker 1992;Becker et al. 2004). It is interesting to note that Aulacella is not recorded within the dark shales of the Matagne Formation as the environment was probably too oxygen-depleted for this genus, which includes some species adapted to deep-water and hypoxic environment. ...
In Belgium, the Lower Kellwasser Event (LKW) corresponds to the relative sea-level
maximum of the first (‘Aisemont sequence’ (AS)) of the two late Frasnian third-order sequences
that are recognized here, but the Upper Kellwasser Event (UKW) may have been triggered by a
series of tsunamites. The end of the middle Frasnian carbonate platform and reefs is caused by
the sea-level drop and emersion of the last middle Frasnian third-order sequence (‘Lion sequence’)
in the Lower
rhenana
Zone. The end of the ‘Petit-Mont’ mudmound growth during the transgres-
sive (TST) and highstand (HST) systems tracts of the AS was caused by sea-level fall and emersion
at the top of this sequence. The coral and brachiopod extinction in the Upper
rhenana
Zone, during
the second late Frasnian third-order sequence (‘Lambermont sequence’ (LS)), is progressive and
due to the widespread development of the dysoxic and anoxic facies, before the UKW. Only the
LS TST has been identified. No sea-level fall has been recognized in relation to the UKW or
near the Frasnian–Famennian boundary. The late Frasnian extinctions are more likely to be
related to the decrease in the atmospheric oxygen rate and its impact on marine environments
and, to complete, the UKW.
... 4 around the Devonian-Carboniferous boundary are Tietze (1870), Paeckelmann (1913Paeckelmann ( , 1930Paeckelmann ( , 1931, Schmidt (1924), Grüneberg (1925), Gallwitz (1932), Weyer (1972Weyer ( , 1979, Bartzsch and Weyer (1986), Becker (1988Becker ( , 1996, Bartzsch et al. (1998), Sartenaer (1997), Afanasjeva (2002) and Müller (2004). Comparatively few similar studies about such rare aphotic Famennian-Hastarian Brachiopoda were published in other countries: Poland (Biernat, 1983(Biernat, , 1988Racki, 1986a, 1986b;Sartenaer, 1998a;Halamski and Baliński, 2009), Czech Republic (Havlíček, 1979), Russia (Rozman, 1962), Algeria (Mottequin et al., 2015a), Morocco (Sartenaer, 1998a(Sartenaer, , 1998b(Sartenaer, , 1999(Sartenaer, , 2000 and China (Sartenaer and Xu, 1990). ...
... 290) admit that also ammonoids of the Clymenia-"Stufe" had been found in their "bed L". The records from Northern Africa are older: Mottequin et al. (2015a) (Algeria, boundary of Platyclymenia-/Clymenia-"Stufe"), Sartenaer (1998b) (Morocco, Clymenia-"Stufe"). The precise age of the Czech type materials from Moravia (Hady Limestone near Brno, "do V-VI") remains unclear without more accurate locality data, e.g., as used by Chlupáč (1966, tab. ...
... fibrosissimum as the predominant species. These rhynchonellides belong to the superfamily Pugnacoidea, of which representatives rank among the most common elements of Devonian-Carboniferous dysaerobic environments (e.g., Bowen et al., 1974;Biernat and Racki, 1986a;Racki, 1989;Alexander, 1994;Sartenaer et al., 1998;Mottequin and Legrand-Blain, 2010;Mottequin et al., 2015a). Palaeobiological implications of the co-occurrence of uniplicate and unisulcate rhynchonellides in Polish contemporaneous succession was discussed by Halamski and Baliński (2009). ...
The geo-heritage of the Saoura Valley in Southwest Algeria is particularly rich and of undeniable scientific value for studying the Palaeozoic, Neogene and Quaternary strata inherited from the Ougarta chain. Although Algeria has always been highly ranked among the most fascinating geodiversity countries, its geological heritage has been seldom described and presented to the African and international community. Subsequently its geodiversity and geo-resources are under-recognized. The Saoura Valley is renowned for its gorgeous geological, oasian and geomorphological landscapes, as well as for its archaeological wealth. In the present paper, we intend to briefly describe the main lithostratigraphic units of the Devonian series exposed in the Saoura Valley and to give an overview of the Quaternary outcrops. Several geo-sites were observed and inventoried, showing a highly significative scientific value and also some remarkable educational and tourism potential as evidenced by their huge historical, archaeological, geological, and cultural heritage. Additionally, the Saoura Valley displays pedagogical geo-sites of cardinal interest for different geological disciplines, among which are stratigraphy, palaeontology, ichnology, geomorphology, geodynamics, structural geology, and ecology, all reflecting the diversified geological record of the area. Besides its aesthetic value, the rich geodiversity of the Saoura Valley displays an obvious scientific and touristic interest. According to the obtained numerical scores using recent quantitative assessment methodology, the Saoura Valley is very promising and can be considered a first-order destination since geo-sites therein score quite a high attraction potential and recreational value for tourism development. These scores ought to be treated with great care by the authorities to effectively promote tourism and to accordingly enhance the local socio-economic development in this remote area. Furthermore, the Saoura Valley area deserves more attention and requires geo-conservation programs and protection strategies right away to make sure that these geo-resources will be preserved for future generations.
The effects of sea-level changes and anoxia on Devonian trilobites have been studied for a long time, but the importance of palaeogeographic and tectonic events in this key-period is still not well understood. In the Devonian Period, trilobites invaded many different marine environments and areas in North Africa where important palaeogeographic changes occurred. Distribution patterns of trilobites through time and space have been analysed using a hierarchical cluster analysis and diversity indices. Our examination of the literature suggests that trilobites were scarce during Lochkovian time before an important diversification in Pragian time. Trilobites flourished in many North African regions without there being important taxonomic differences between basins, because of free migration in relatively flat palaeo-topography and homogeneous environments. During Middle Devonian time, early Variscan tectonic movements transformed the eastern Anti-Atlas area into a basin with a platform topography. Geographical barriers such as deep basins prevented trilobite migrations. At the beginning of Eifelian time, the reduction in migration between the different regions of this area coincided with a decrease in diversity. Consequently, tectonic events played an important role in the decline of trilobites during Middle Devonian time, especially when these were combined with sea-level changes and anoxic/hypoxic events. A recovery occurred in Famennian time involving only new genera. As at the global scale, cyrtosymbolines developed in shallow seas, whereas phacopids evolved in deeper environments. The basin and platform system still hampered migrations, although sea-level variations led to episodic exchanges. The late Famennian regression reduced trilobite diversity dramatically in the study area.
The lower Famennian ‘ Cyrtospirifer ’ orbelianus brachiopod Zone established in Armenia by Abrahamyan (1957) (coeval to the crepida conodont Zone) contains an abundant and diverse brachiopod fauna that still remains poorly studied. In an effort to revise and update its systematic classification and to assess the brachiopod diversity in this area after the Kellwasser extinction event at the end of the Frasnian, our attention is here focused on rhynchonellides and athyrides. Six rhynchonellide species are described belonging to five genera as well as a single athyride species ( Crinisarina pseudoglobularis n. sp.), which is new to science. The genus Crinisarina is reported for the first time in the South Armenian Block (SAB), which was then part of the northern margin of Gondwana. Some of the rhynchonellides identified were previously recognized in this area, but they require modern documentation and taxonomic reassessment. More particularly, it is the first time that the internal structure of Sartenaerus baitalensis (Reed, 1922) is illustrated, taking into account that it is the type species of a biostratigraphically significant Famennian genus. One of the oldest punctate rhynchonellide species, Greira transcaucasica Erlanger, 1993, is described for the first time from Armenia and its intraspecific morphological variability is documented quantitatively. From a paleobiogeographic viewpoint, the studied brachiopod fauna clearly shares affinities with contemporaneous ones from other regions of the Gondwanan northern margin that extend eastwards of the SAB to Afghanistan and Pamir, although there are also some endemic elements.
UUID: http://zoobank.org/798eb5f9-ad15-4d90-bc6a-ff22ee936438
