Heterosporous Ferns From Patagonia

Azolla Sporophytes and Spores from the Late Cretaceous and Paleocene of Patagonia, Argentina

“…Plant macrofossils and associated microfossils (algae, spores, and pollen) are known from the Cañadón del Irupé, Quebrada del Helecho, and Cerro Bosta localities of the La Colonia Forma-tion (Gandolfo and Cúneo 2005;Cúneo et al 2013Cúneo et al , 2014Gallego et al 2014;Gandolfo et al 2014;Hermsen et al 2014;De Benedetti et al 2018). Although Azolla spores have been recovered from all of these localities (Cúneo et al 2014;Gandolfo et al 2014;De Benedetti et al 2018), Azolla sporophyte material has been found only at the Cañadón del Irupé locality (Cúneo et al 2014;Gandolfo et al 2014). The La Colonia Formation is thought to be largely Campanian to Maastrichtian in age (but may also include sediments that are younger and older near the top and bottom, respectively) based on several biostratigraphic markers such as palynomorphs, foraminifera, marine invertebrates, and dinosaurs (see Pascual et al 2000, as well as citations therein).…”

“…Terminology applied to the megaspore apparatus and microspore massula varies and in some cases is defined inconsistently; terminology in this article follows the usage in De Benedetti et al (2018) and the references cited therein. Brief definitions of selected terms for reproductive features as used in this article are given in appendix A (apps.…”

“…Lectotype designated here. MPEF-PA 80, megaspore apparatus illustrated by De Benedetti et al (2018), plate I, figure 1. Held at the Museo Paleontológico Egidio Feruglio, Trelew, Chubut Province, Argentina.…”

“…Type locality. Cañadón del Irupé locality, Chubut Province, Patagonia, Argentina (see Cúneo et al 2014;Gandolfo et al 2014;De Benedetti et al 2018).…”

“…The megaspore apparatuses and microspore massulae were described as Azolla coloniensis Remarks. Several types of salviniaceous spores are known from the La Colonia Formation: Azollopsis, Azolla coloniensis, an unnamed species of Azolla, and the monotypic taxon Paleoazolla patagonica (Archangelsky et al 1999;Cúneo et al 2014;Gandolfo et al 2014;De Benedetti et al 2018, 2019a. Of these, two have been recovered from sediments at the Cañadón del Irupé locality: A. coloniensis (De Benedetti et al 2018) and P. patagonica ( fig.…”