Also known as Solanutherium walshi locality

Where: Río Negro, Argentina (39.8° S, 66.7° W: paleocoordinates 42.6° S, 52.4° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Lower Member (Allen Formation), Late/Upper Campanian to Late/Upper Campanian (83.5 - 66.0 Ma)

• The Allen Formation comprises the lowest layer of the Malargüe Group, which overlies the Neuquén Group in northern Patagonia (Riccardi, 1991; Garrido, 2010). Both the Malargüe and Neuquén Groups are Upper Cretaceous in age (Uliana and Dellapé, 1981). The Allen Formation lacks absolute dating, but it lies below the Maastrichtian Jagüel Formation, which contains the Cretaceous-Paleogene boundary (Leanza and Hugo, 2001; Rougier et al., 2009a). It overlies the Campanian Anacleto Formation of the Neuquén Group (Garrido, 2010). The age of Allen Formation can therefore be estimated as Campanian-Maastrichtian, likely Late Maastrichtian. This age is congruent with estimates based on faunal composition.

• bed-level stratigraphic resolution

Environment/lithology: fluvial; poorly lithified, fine-grained, yellow sandstone and mudstone

Size classes: macrofossils, mesofossils

• Mammals teeth

Collected by G. W. Rougier & crew in 2009

Collection methods: bulk, quarrying,

• MML, Museo Municipal de Lamarque, Río Negro, Argentina.

•A variety of methods were employed during screen washing, mainly power-fed water run through a successive set of screens of different sizes. Slower, gentler, and more time-consuming methods did not result in materials of appreciably greater quality. Picking was performed by expedition members and museum staff at Museo Municipal de Lamarque (MML), Río Negro, Argentina; some of the very early samples were picked at El Matuasto ranch (39° 46’ 53.65 S; 66° 33’ 44.5 W). Screen washing was done using mesh screens (McMaster-Carr catalog 9238T44) with a minimum size of 0.61 mm. After picking, specimens were prepared and mounted following procedures developed for the managing of small size specimens (Biven-Leslie and Rougier, 2021). Maximum length and width of mounted specimens, as well as relevant angles, were measured using a Bausch & Lomb StereoZoom 4 microscope at 2x magnification with micrometer. During the preparation process, silicone molds and resin casts were created for archival purposes and to facilitate illustration and photography (silicone GT products 5092 and BJB Enterprises TC-982 A/B resin). Photographs of each specimen were taken in occlusal, buccal, lingual, distal, and mesial views using a Nikon D7100 camera.

Primary reference: B. E. Connelly, M. S. Cardozo, J. D. Montgomery and G. W. Rougier. 2024. New mammals from the Upper Cretaceous Allen Formation (Patagonia, Argentina) and reassessment of meridiolestidan diversity. Cretaceous Research 162(105935) [E. Vlachos/F. Aspromonte/F. Aspromonte]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 235138: authorized by Evangelos Vlachos, entered by Franco Aspromonte on 06.06.2024

Creative Commons license: CC BY (attribution)