Taxonomy and palaeobiogeography of the early and middle Albian (Early Cretaceous) bivalves and brachiopods from central Serbia (Topola, Oplenac Hill)

Abstract

Sixteen early and middle Albian bivalve species, belonging to fourteen genera, eleven families and seven orders, and one brachiopod species are systematically described from the Mitrovčić section near Topola (Oplenac Hill), Vardar Zone of central Serbia. Four bivalve species: Acesta subrigida (Roemer, 1836), Acesta cf. dorbignyana (Mathéron, 1843), Neithea (Neithea) sexcostata (S. Woodward, 1833), “Cardium” cottaldinum d'Orbigny, 1844, and one terebratulide species, Praelongithyris rogeri Gaspard, 1974 are recorded from the lower and middle Albian rocks of central Serbia for the first time. The section comprises reddish ferruginous calcareous sandstones that are assigned to the lower Albian as indicated by the presence of the ammonite Douvilleiceras mammillatum (Schlotheim), while yellowish sandy wackestones/packstones located below the late Albian Mortoniceras (M.) inflatum (J. Sowerby), are middle Albian in age. Most of the identified bivalve taxa have a Tethyan affinity and seem to be closest to faunas from western and eastern Europe. This indicates that these regions were close to Serbia during the early–middle Albian. The occurrences of some of these Tethyan bivalves at the northern and western Pacific coast of South America and southern coast of North America is explained by dispersal through the opening of the North Atlantic Ocean during the Albian (Proto-North Atlantic Ocean). Meanwhile, the occurrence of some other Albian taxa along the eastern coast of South America (South Atlantic) was probably a result of the opening of the equatorial Atlantic gateway during that time. The faunas are not endemic, indicating that the larvae were long-lived and possessed a high dispersal potential, facilitated by seaways during the Albian.