Early Silurian-Early Devonian acritarchs and prasinophytes from the Ananea and San Gabán Formations, southern Peru and their paleogeographic implications

Distinctive palynomorph associations have been recovered from selected samples in the Ananea and San Gaban formations in southern Peru. A total of 38 genera and 71 species of acritarchs and prasinophytes have been identified, with several forms in open nomenclature. Palynomorph vesicle walls are affected by slight metamorphism, and thermal alteration indices range from 3 to 3+. Age-diagnostic species, such as Chutecloska athyrma Loeblich & Wicander, 1976, Domasia elongata Downie, 1960, Riculasphaera fissa Loeblich & Drugg, 1968, and Thysanoprobolus polykion Loeblich & Tappan, 1970 are present in the Ananea Formation. The species Hoegklintia visbyensis (Eisenack) Dorning, 1981, recovered from the San Gaban Formation, supports its Early Silurian age. Palynomorphs of terrestrial origin, such as miospores and resistant plant tissues, are either completely absent or extremely rare. Despite the rather sparse record and low number of productive samples, palynology allows assignment of an Early Silurian (late Llandovery to 157 Revista Espanola de Micropaleontologia, 43 (3), 2011, pp. 157-172 ©Instituto Geologico y Minero de Espana ISSN: 0556-655X