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Journal of Paleontology 92(3):336–372


Paleobiogeography.—Similar pararathuramminid microfaunas seem to be present in the entire Palaeotethys from western France to Tajikistan and even South China. Our assemblage in particular aligns with those of the calcaires de Chalonnes in western France (Dubreuil and Vachard, 1979) and of Causse de Laurens in southern France (Vachard unpublished data), but they seem to be relatively distinct from those of Germany (Körk, 2016) and Moravia (Pokorny, 1951); however, a paleoecologic control is possible, because these latter inhabited deeper seas. In the Carnic Alps, the Givetian sea was probably located between the Armorica-Perunia and Peri-Mediterranean micro- continents, which communicated easily with other shallow seas with the Ural Ocean, Siberia, and Kazakstania on one side, and eastern North America and other parts of Laurussia on the other side (Kalvoda, 2001, 2002; Kalvoda and Bábek, 2010). The shallow-marine Devonian limestone (Feldkogel Limestone; Polinik Formation) was deposited on a shallow shelf that was part of the Noric Composite Terrane (Frisch and Neubauer, 1989), of the Carnic-Dinaric Microplate (Vai, 1991, 1998), or of the Adria-Dinaria Megaterrane (Ebner et al., 2010).


Foraminiferal macroevolution.—There are no direct arguments to prove that the parathuramminids, earlandiids, pseudoammo- discids, irregularinoids, and tuberitinids are foraminifers, but two indirect arguments permit this interpretation: (1) all these groups are first agglutinated, and then all become secreted with microgranular tests during the Givetian revolution; and (2) even if monothalamous skeletons exist in different botanical and zoological groups, tests such as those of parathuramminids are only known among foraminifers, with an indisputable extant genus Thurammina. It seems also that the Paleozoic foraminifers can display either agglutinated tests or secreted tests (Fig. 11). That is clear for the plurilocular foraminifers (see Vachard, 2016a; particularly with the example of Rectoseptatournayella and Ammobaculites), but is more disputable for the monothalamous and bilocular taxa in which the nomenclature is double, both for genera (Thurammina/ Parathurammina; Ammodiscus/Pseudoammodiscus; Earlandia/ Hyperammina; Archaelagena/Paralagena; etc.), as well as for orders (Fig. 11): (Thuramminida/Parathuramminida; Ammo- discida/Archaediscida; Hippocrepinida/Earlandiida); and finally between the classes Fusulinata and/or Textulariata/Astrorhizata (Vachard, 2016a, b). As a result, it is probable that many homeomorphs of different classes have been confused in the foraminiferal literature. Inversely, with the hypothesis of a calcareous foraminiferal test secreted in isotopic equilibrium with ambient seawater (Langer, 1995), it is possible that when calcification isweaker in deeperwaters, an agglutinate can replace the deficient calcification of a shallow-water genus. However, it is noteworthy that, because all foraminiferal agglutinated tests are contemporeaneously replaced by secreted calcareous forms (Fig. 11) in the five groups (parathuramminids, irregularinoids, tuberitinoids, pseudoammodiscids, and earlandiids) during the Givetian revolution (Vachard et al., 2010), it is possible to conclude: (1) that the five groups have common wall micro- structures, (2) consequently all belong to foraminifers, and (3) they belong to distinct orders (Fig. 11). The initial phase of foraminiferal history, from Cambrian to Early Devonian, was dominated by agglutinated tests. TheGivetian


Figure 11. Phylogenetic hypothesis about the most primitive lineages of foraminifers (agglutinated and secreted). Abbreviation: Pennsylvan.= Pennsylvanian.


(Middle Devonian) revolution resulted in the replacement of these agglutinated tests by calcareous secreted tests (Vachard et al., 2010). Lower Paleozoic agglutinated foraminifers are considered to belong to the classes Textulariata (Loeblich and Tappan, 1964, 1987) and/ or Astrorhizata (Vdovenko et al., 1993; Mikhalevich, 2003), but these so-called agglutinates also could have resulted from recrystallization of secreted tests. With the Frasnian-Famennian crisis, the first evolutive phase of the foraminifers was completed, and the second phase started and lasted until the Permian-Triassic boundary, where life on the Earth nearly disappeared completely and our biological references almost entirely changed.


Conclusions


There are nine main conclusions from this study: (1) a rich microfauna of foraminifers, which is accompanied by an amphiporid macrofauna, has been discovered in the Feldkogel Limestone (Polinik Formation) at Mount Polinik (Carnic Alps, Austria); (2) the limestones of Mount Polinik possibly display the Eifelian–Givetian boundary interval (samples 1–10), the


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