A brief note on the paleofauna of "Tartaruguito site", Adamantina Formation, Bauru Group, Brazil

Abstract

The genera Nuculites and Cucullella have originated in different geographic areas, with the oldest record found in the Llandovery (Lower Silurian). The former was reported in Gondwana with two subgenera, Nuculites and Trilobonuculites, while the latter is found in Avalonia. Due to environmental and tectonic factors, those taxa became associated and distributed throughout Gondwana, Avalonia, Kazakhistan and Laurussia from the Late Silurian to the Late Devonian. The subgenus Trilobonuculites appeared firstly at the Pitinga Formation, Amazon Basin, Brazil, and the subgenus Nuculites is only recorded in the Silurian from the Tabuk Formation, Saudi Arabia. Cucullella was found in the Ross Brook Formation of New Scotia, Canada. Since the Late Silurian (Ludlow), which is marked by a marine transgression, Trilobonuculites and Cucullella started to occur associated, invading other paleocontinents, confirmed by the presence of Cucullella in the Gondwana (Bolivia) and Trilobonuculites in Avalonia (New Scotia). This suggests that the environment in these areas became more uniform due to the rise of the sea level and the narrowing of the ocean Rheic. The Silurian-Devonian boundary is marked by a marine regression followed by a new transgression, with maximum in the Frasian, and the collision of Avalonia/Baltica and Laurentia forming Laurussia. At this point, the subgenus Nuculites reappeared. Still in the Lower Devonian (Pragian-Emsian), the genus Nuculites diversified, dominating by the subgenus Trilobonuculites, while Cucullella was only represented by a sole species from Kazakhistan. In the Middle Devonian (Eifelian-Givetian) the subgenus Nuculites predominated while Trilobonuculites was restricted to the Maecuru Formation (Brazil). The only species of Cucullella dispersed to the oriental Laurussia and North and Occidental Gondwana. In the Late Devonian (Frasnian), the occurrence of these taxa was restricted to the Armorican Massif, Northeastern of Brazil and some doubtful occurrences in Bolivia. At that time, the oceans deepened, dysaerobic and anoxic environments spread out and Gondwana and Laurussia were approaching. These factors, associated with thermal stress, led to extinction of several taxa at the Frasnian/Fammenian boundary, including those studied here. The paleogeographic distribution of Nuculites and Cucullella agrees with the sea level curves and the movement of the continents suggested to have taken place during the Silurian and Devonian.-(

Descrição morfológica e posicionamento filogenético de um Baurusuchidae (Crocodyliformes, Mesoeucrocodylia) do Cretáceo Superior da Bacia Bauru, região de General Salgado (SP).

“…Os problemas relacionados à tafonomia dos fósseis da Bacia Bauru ainda residem na ausência de levantamentos básicos. Existem poucas tentativas pontuais de uma abordagem mais detalhada acerca da caracterização tafonômica de algumas ocorrências fossilíferas (Henriques et al, 2002;Bertini et al, 2006e Vasconcellos & Carvalho, 2006 e de uma abordagem regional quanto aos estilos de fossilização presentes (Goldberg & Garcia, 2000;Coimbra & Fernandes, 1998). Muito mais raros são os trabalhos que abordam os problemas da mistura temporal e espacial presentes nas assembléias (Pires-Domingues et al, 2006;Pires-Domingues, 2006), fundamentais para as interpretações paleoecológicas e paleoambientais.…”

Intra-specific variation and allometry of the skull of Late Cretaceous side-necked turtleBauruemys elegans(Pleurodira, Podocnemididae) and how to deal with morphometric data in fossil vertebrates

“…Many articulated and complete fossils are found in these sequences, which indicate seasonal low energy floods (mudstones) followed by droughts (sandstones) in the region during the Late Cretaceous (Henriques et al, 2002; Henriques et al, 2005; Henriques, 2006). Because only medium- to large-sized fossil specimens are found at the locality, it is assumed that the Tartaruguito site was a foraging area for turtles (D Henriques & L Carvalho, pers.…”

Peer Review #1 of "Intra-specific variation and allometry of the skull of Late Cretaceous side-necked turtle Bauruemys elegans (Pleurodira, Podocnemididae) and how to deal with morphometric data in fossil vertebrates (v0.2)"

“…; (3) the Middle-Upper Paleocene Cerrejón Formation in Colombia (Jaramillo et al, 2007;Cadena et al, 2010;Cadena, Bloch & Jaramillo, 2012;Cadena et al, 2012); and (4) the Upper Miocene Urumaco Formation ('Capa de tortugas') in Venezuela (Aguilera, 2004;Sánchez-Villagra & Aguilera, 2006;Sánchez-Villagra & Winkler, 2006;Riff et al, 2010;de la Fuente, Sterli & Maniel, 2014). The two latter localities are near-shore marine coastal deposits with influence of freshwater rivers (Jaramillo et al, 2007;Gaffney et al, 2008), whereas the two former and the Tartaruguito site correspond to sediments that had been deposited in a riverine system with seasonal droughts in which turtles gathered in retreating, ephemeral water pools and died when habitat dried up completely (Soares et al, 1980;Fulfaro and Perinotto, 1996;Fernandes & Coimbra, 2000;Henriques et al, 2002Henriques et al, , 2005Murphy et al, 2003;Bertini et al, 2006;Henriques, 2006;Wings et al, 2012). The Tartaruguito is also the type-locality of the peirosauridcrocodile Pepesuchus deiseae Campos, Oliveira, Figueiredo, Riff, Azevedo, Carvalho & Kellner, 2011(Campos et al, 2011.…”

“…The general lithology of the Tartaruguito site is composed of cyclic alternations of sandstones and mudstones deposited in a meandering fluvial system with crevasse splays (Fernandes & Coimbra, 2000;Henriques et al, 2005;Bertini et al, 2006). Many articulated and complete fossils are found in these sequences, which indicate seasonal low energy floods (mudstones) followed by droughts (sandstones) in the region during the Late Cretaceous (Henriques et al, 2002(Henriques et al, , 2005Henriques, 2006). Because only medium-to large-sized fossil specimens are found at the locality, it is assumed that the Tartaruguito site was a foraging area for turtles (D. Henriques, pers.…”

“…Manuscript to be reviewed and crocodiles, while during the dry seasons turtles gathered on the remnants of water pools and some died when pools dried up completely (Henriques et al, 2002(Henriques et al, , 2005Henriques, 2006).…”