A Revision of the Triassic and Jurassic Tetrapod Footprints of Argentina and a New Approach on the Age and Meaning of the Botucatu Formation Footprints (Brazil)

Abstract

DAS DA FORMAÇÃO BOTUCATU (BRASIL). São expostos os resultados de uma expedição pela Argentina, durante a qual foi examinado o material icnoldgico argentino referente aos tetrápodes, do Carbonffero ao Pleistocene. São descritas, classificadas, ilustradas e revisadas, aqui, de maneira preliminar, apenas as icnofaunas argentinas de idade triássica e jurassica. Tais dados são comparados com as icnofaunas de tetrápodes da Formação Botucatu, no Estado de São Paulo. Esta icnofauna é de difícil classificação, posto que se trata de uma associação completamente nova. Deve ser mencionado que o material não é, em geral, de boa qualidade. As associações Triássicas da Argentina, representadas pelas localidades de Lãs Higueras, Campo de Ischigualasto, Quebrada Los Rastros, Rio Los Tarros-Sur Pagancillo e Los Menucos, são caracterizadas pela presença, em quantidades variáveis, de terápsides e poucos arcossauros, entre os quais predominam os tecodontes quadrúpedes. Os mamíferos são raros. Pelo contrátrio, na associação jurássica de Laguna Manantiales, há uma predominância dos mamíferos, acompanhada de quatro formas dinossaurianas, e ausência de terápsides e tecodontes quadrúpedes. A Formação Botucatu, nos arredores de Araraquara, possui uma icnofauna na qual predominam os mamíferos primitivos, acompanhados de poucos dinossauròides bfpedes e poucos terápsides atribuídos tentativamente a Tritylodontoidea. A comparação detalhada entre a estrutura das diversas associações permite atribuir a Formação Botucatu, pelos menos no Estado de São Paulo, ao Jurássico Inferior ou Médio.

A Late Jurassic fossil assemblage in Gondwana: Biostratigraphy and correlations of the Tacuarembó Formation, Parana Basin, Uruguay

“…To date, no fossils have been recorded from this unit, although the aeolian facies are probably correlative with rocks in Brazil (i.e., the Botucatu and Guará Formations) where ichnofossils are attributed to theropod, ornithopod and sauropod dinosaurs, as well as to mammals, these were described by some of them very close to the international border with Uruguay, near Santa Ana do Livramento City (Leonardi and Oliveira, 1990;Schultz et al, 2002;Fernandes et al, 2004;Dentzien-Dias et al, 2007).…”

“…For example, the Tacuarembó Formation was partially correlated with the Pirambóia Formation of Brazil, for which Scherer et al (2000) propose a Late Permian age, but which Soares (1975) and Assine et al (2004) consider Triassic. Other Brazilian lithostratigraphic correlatives of the Tacuarembó Formation are the Botucatu and Guará Formations from which there are no temporally indicative fossils known at present (Leonardi and Oliveira, 1990;Schultz et al, 2002;Dentzien-Dias et al, 2007). In the Parana Basin, the Tacuarembó Formation is the only unit which has yielded chronologically indicative fossils from the interval considered.…”

Fossilized excreta associated to dinosaurs in Brazil

“…The São Bento quarry has been in operation for more than fourty years producing flagstones used as wall coverings and to pave sidewalks. Many flagstones are rich in vertebrate and invertebrate ichnofossils (Leonardi, 1980(Leonardi, , 1984Leonardi and Oliveira, 1990). The trace fossils are considered to be the first fossil evidence for the preservation of sedimentological features resulting from the ejection of liquid from dinosaurs.…”

Triassic pentadactyl tracks from the Los Menucos Group (Río Negro province, Patagonia Argentina): possible constraints on the autopodial posture of Gondwanan trackmakers

“…Later, other contributions focused on important Triassic ichnofaunas from other regions of Argentina have been published (e.g., Romer, 1966; Bonaparte, 1966; Leonardi, 1994; Melchor & de Valais, 2006). Among the Triassic vertebrate ichnological record, the Los Menucos ichnofauna, which is dominated by small therapsid footprints, was repeatedly studied (Casamiquela, 1964; Casamiquela, 1975; Casamiquela, 1987; Leonardi & De Oliveira, 1990; Leonardi, 1994; Domnanovich & Marsicano, 2006; Melchor & de Valais, 2006; de Valais, 2008; Domnanovich et al, 2008; Díaz-Martínez & de Valais, 2014). The bulk of this ichnofauna was originally attributed to different ichnotaxa by Casamiquela (1964) and Casamiquela (1975), but after the revision made by Melchor & de Valais (2006), most of the ichnogenera erected by Casamiquela are considered synonymous with Dicynodontipus .…”