The Bylot basins of northeastern Canada and northwestern Greenland comprise the Borden, Aston-Hunting, Fury and Hecla, and Thule basins. This system of late Mesoproterozoic (ca. 1.27– 1.0 Ga) sedimentary basins preserves an important record of present-day northeastern Laurentia coincident with the emplacement of the Mackenzie Large Igneous Province, the Shawinigan and Ottawan phases of the Grenville orogeny, and the development of the Midcontinent Rift. However, establishing correlations between the sedimentary successions of the Bylot basins has been hindered by the absence of robust chronostratigraphic constraints. As a result, the degree to which these basins were interconnected, whether they share a common tectonostratigraphic history, and how their sedimentary patterns relate to regional tectonic events remain open questions. Recent Re-Os geochronology from organic-rich strata has yielded depositional ages from the Borden (1048 Ma and 1046 Ma) and Fury and Hecla (1087 Ma) basins, which we integrate with existing models for the depositional history of these basins to derive three tectonostratigraphic assemblages from the Bylot basins. We project our refined tectonostratigraphic framework for the Borden and Fury and Hecla successions to Greenland in order to establish a testable hypothesis for how the Thule Supergroup fits into this tectonostratigraphic picture.

We report new data on the geology and the fossil record of the Sanfranciscana Basin in sites to the north of the traditionally explored localities within Minas Gerais. The strata in the new explored area are formed by distinct lithologies, encompassing pelitic rocks with caliche levels and metric bodies of cross-bedded sandstone towards the top, similar to the fluviolacustrine beds of the Areado Group in the southern portions of the basin. Also similar to other regions of the São Francisco Craton, the deposits of the Sanfranciscana Basin studied herein lie discordantly to the rocks of the Bambuí Basin. We preliminarily report neopterygian fish scales, little informative archosaurian bones and an association of the ostracods Ilyocypris- Fossocytheridea. This ostracod association is registered for the first time in the Cretaceous of the Sanfranciscana Basin. The ostracods have been collected from the lacustrine, vertebrate-bearing rocks cropping out in Lagoa dos Patos and Coração de Jesus. The cytherideid Fossocytheridea assigns a minimal Aptian age to its bearing rocks. Its association with Ilyocypris was also reported in Upper Cretaceous oligohaline paleoenvironments in Brazil and Argentina, indicating similar depositional conditions to the strata reported in this paper. The putative affinities of the specimens of the Sanfranciscana Basin with F. ventrotuberculata, and their association with Ilyocypris, raise the hypothesis of a younger age for some levels of that basin in northern Minas Gerais, perhaps ranging into the Late Cretaceous. Keywords: Ostracoda, Archosauria, Areado Group, Cretaceous, Gondwana