The crocodylomorph fauna of the Cenozoic of South America and its evolutionary history: a review

The feeding habits of the strange crocodylian Mourasuchus (Alligatoroidea, Caimaninae): a review, new hypotheses and perspectives

“…As such, semi-aquatic crocodylomorphs had not only an ever-growing habitable space but also had ever-growing different kinds of habitats in the aquatic systems of the Cenozoic of South America which, together with the generally hot climate and high biodiversity (which generated a vast array of prey items), were the factors that allowed the Caimaninae clade to evolve the distinctly different morphotypes it exhibited in the Miocene, including the "gulp-feeding" habit of Mourasuchus. In this context, it is interesting to notice that the reduction in the size of the water systems of the Amazon area during and after the late Miocene are coincident with the extinction of all the large and specialized crocodylomorphs, such as Mourasuchus, Purussaurus, durophagous caimanines, gavialoids and the longirostrine crocodyloids Charactosuchus and Brasilosuchus (see Riff et al, 2010;Scheyer et al, 2013;Cidade et al, 2019), which reinforces the importance of large water systems for the survival and evolution of large, specialized semi-aquatic crocodylomorphs. Additionally, it is also possible that the sebecid terrestrial-oriented morphology was also less "plastic" that that of the semiaquatic, brevirostrine caimanines, but this issue must also be addressed by future, detailed studies.…”

“…The evolution of the peculiar feeding of Mourasuchus is another consequence of the environmental conditions that allowed the establishment of an especially rich, morphologically diverse community of crocodylomorphs in the Miocene of South America. In this context, it is interesting to notice that from the four lineages that comprised such Miocene diversity (Sebecidae, Caimaninae, Gavialoidea and Crocodyloidea), two of them were already inhabiting South America by the Paleocene (Sebecidae and Caimaninae; see Bona, 2007;Riff et al, 2010;Brochu, 2011;Pol & Powell, 2011;Kellner et al, 2014;Cidade et al, 2019), while the first record of Gavialoidea for the continent is from the upper Oligocene/lower Miocene (Moraes-Santos et al, 2011) and the first records of Crocodyloidea (the putative tomistomine genera Charactosuchus and Brasilosuchus) are from the Miocene (see Riff et al, 2010), whereas the genus Crocodylus that currently inhabits the continent has its record beginning only in the Pliocene (Scheyer et al, 2013).…”

“…Of all these four lineages, Caimaninae is the one that exhibits the largest and most conspicuous morphological disparity in the Miocene, possessing morphotypes ranging from generalist predators (Melanosuchus, Paleosuchus), predominately durophagous (Gnatusuhcus, Kuttanacaiman, Globidentosuchus, Caiman brevirostris), the giant generalist predator Purussaurus and the gulp-feeding Mourasuchus (Cidade et al, 2019). These two taxa were also especially large crocodylians, with Mourasuchus reaching up to 6.6 m (Langston, 2008) and Purussaurus up to 12.5 m. (Aureliano et al, 2015).…”

“…The fossil crocodylomorphs of the Miocene of South America comprise one of the largest, most taxonomically diverse and morphologically disparate faunas of the Crocodylomorpha clade (Langston, 1965(Langston, , 2008Gasparini, 1996;Langston & Gasparini, 1997;Paolillo & Linares, 2007;Salas-Gismondi et al, 2007Riff et al, 2010;Scheyer & Moreno-Bernal, 2010;Bona et al, 2013a;Scheyer et al, 2013;Bona & Barrios, 2015;Moreno-Bernal et al, 2016;Scheyer & Delfino, 2016;Souza et al, 2016;Cidade et al, 2017Cidade et al, , 2019. This includes not only records of the extant genera Paleosuchus (Salas-Gismondi et al, 2007), Melanosuchus (Medina, 1976;Bona et al, 2017;Foth et al, 2017) and Caiman (Souza-Filho, 1987;Fortier et al, 2009;Bona & Carabajal, 2013;Bona et al, 2013aBona et al, , 2014Fortier et al, 2014;Salas-Gismondi et al, 2015), but perhaps the most impressive examples of such diversity are the crocodylomorphs whose morphology, ecological niche and feeding habits differ substantially from those of the extant crocodylians.…”

Primeiro registro fóssil de Alligatoridae do Mato Grosso do Sul e o valor sistemático das rosáceas em Caimaninae

“…A família Alligatoridae Gray, 1844 atualmente é representada pelos gêneros viventes Caiman Spix, 1825, Melanosuchus Gray, 1862, Paleosuchus Gray, 1862 Schneider, 1801(Richardson et al 2002Vitt & Caldwell 2009). O registro fóssil de crocodilomorfos pleistocênicos na América do Sul (Figura 1) abrange táxons de Crocodylidae Cuvier, 1807, Gavialidae Hay, 1930 e Caimaninae, sendo mais abundante em território brasileiro (Fortier & Rincón 2013;Cidade & Hsiou 2018). Fósseis de Alligatoridae foram apontados para os estados de Rondônia (Andrade et al 2010), Bahia (Fortier et al 2010;Castro et al 2014), Piauí (Guidon et al 2009), Rio Grande do Norte (Porpino et al 2004;Marinho et al 2005), Ceará (Araújo-Júnior et al 2010), Mato Grosso (Hirooka 2003), Rio Grande do Sul (Hsiou & Fortier 2007) e Sergipe (de Melo França et al 2014) e com certa dúvida Minas Gerais (Lydekker 1888;Patterson 1936).…”