Description and interpretation of Cenozoic vertebrate ichnofossils in Rio Grande do Sul State, Brazil

Abstract

In the neighborhood of the city of Boqueirão do Leão (State of Rio Grande do Sul, Brazil) a set of three big-sized tunnels has been found. One of the tunnels is only partially fi lled with sand and accessible along its entire length. It is horizontal, slightly sinuous, 36 m long, up to 4.2 m wide and up to 2.0 m high. The surface morphology of the walls is composed of anthropogenic marks, speleothems, black incrustations and traces like digging scratches and smoothed surfaces. The 2 nd tunnel has its entrance blocked by sand and sandstone cobbles, but the end of the tunnel is only partially clogged and therefore accessible. This accessible portion is 12 m long, 3 m wide and 1.5 m high. The 3 rd tunnel is completely fi lled and collapsed and is nowadays only indicated by concave roof features at its end. The general features of the tunnel system and the analysis of the surface morphology of the walls of the accessible portions permit to conclude that the tunnels were produced by ground sloths of the Cenozoic South American megafauna. The size of the tunnels suggests that its excavation was gradually carried out by successive generations of sloth herds, and not by a single individual animal. The primary function of the tunnels probably was not protection from predators, which had easy access to structures of this size, but to shelter during a drier climate. However, it is not yet possible to relate the tunnels to a specifi c ground sloth genus, a task that depends on the discovery of better-preserved tunnel systems.RESUMO -Nas imediações da cidade de Boqueirão do Leão (Estado do Rio Grande do Sul, Brasil) foi encontrado um conjunto de três túneis de grande porte. Um dos túneis está apenas parcialmente preenchido com areia e acessível em toda a sua extensão, sendo horizontal, levemente sinuoso com 36 m de comprimento, largura de até 4.2 m e altura de até 2 m. A morfologia das paredes do túnel é composta por marcas antropogênicas, espeleotemas, incrustações pretas e marcas de paleovertebrados como marcas de escavação e superfícies alisadas. O segundo túnel tem sua entrada bloqueada por areia e seixos de arenito, mas a porção fi nal do túnel está apenas parcialmente preenchida e, portanto, acessível. Esta porção acessível possui 12 m de comprimento, 3 m de largura e 1,5 m de altura. O terceiro túnel está completamente preenchido e desabado e pode ser reconhecido atualmente apenas pelas feições côncavas do teto em seu fi nal. As características gerais do sistema de túneis e a análise da morfologia das paredes das porções acessíveis permite concluir que os túneis foram produzidos por preguiças terrestres da Megafauna Cenozoica sul-americana. O tamanho dos túneis sugere que sua escavação foi gradual, realizada por gerações sucessivas de grupos de preguiças, e não por um animal individual. A função primária dos túneis provavelmente não foi proteção de predadores, que tinham fácil acesso a estruturas desse tamanho, mas abrigo durante um clima mais seco. Entretanto, ainda não é possível relacionar os túneis a um gênero espe...

Giant paleoburrows in the Porto Alegre metropolitan area (state of Rio Grande do Sul, Brazil).

“…In Argentina, such papers are of Quintana (1992), Zárate et al (1998), Vizcaíno et al (2001), Dondas et al (2009), Cenizo et al (2016) and Cardonatto & Melchior (2018). In Brazil, research of such approach is from Padberg-Drenkpol (1933), Berqvist & Maciel (1994), Buchmann et al (2009Buchmann et al ( , 2016, Carmo et al (2011), Frank et al (2012a, 2013, 2015, Ruchkys et al (2014), Lopes et al (2017), Faria et al (2019), Vidal et al (2019), Budke et al (2020) and Schipanski et al (2022). From other South American countries, the paper of Hostnig (2019) describes a cave in Peru where digging traces attributed to ground sloths of the megafauna are covered by pre-Hispanic paintings.…”

Megaichnus igen. nov.: Giant Paleoburrows Attributed to Extinct Cenozoic Mammals from South America

“…3), located about 2 meters above the ground. These surfaces do not exhibit claw impressions, and their origin is attributed to the friction produced by constant rubbing of the animals against the walls and ceiling (Frank et al, 2013). The smoothing along the approx.…”

“…Megaichnus major n. isp. This ichnospecies consist of large burrows (also called "megatunnels"), whose type specimen is the larger burrow described by Frank et al (2013) in the locality of Boqueirão do Leão (Fig. 3A).…”

Geomorphology and sedimentology of the Cerro Benítez of the cavities (Patagonia, Chile): genesis and evolution of a megafauna sedimentary trap during the last glaciation

“…Au Brésil et en Argentine, des galeries d'âge pléistocène, creusés dans des substrats indurés tels que des grès, témoignent de moeurs fouisseuses chez la mégafaune éteinte d'Amérique du Sud. D'un développement de 60 m pour une largeur maximale de 4 m, ces terriers sont attribués aux paresseux géants Scelidotherium, Lestodon et Glossotherium en raison de leurs dimensions, et d'après des preuves morphologiques, telles que des marques de griffes (Vizcaíno et al, 2001 ;Buchmann et al, 2009 ;Frank et al, 2013 ;Lopes et al, 2017). Aucune marque de griffe n'atteste un tel comportement au Cerro Benítez.…”