Macrauchenia patachonica Owen (Mammalia, Litopterna) de la région de São Raimundo Nonato (Piauí, Nordeste brésilien) et la diversité des Macraucheniidae pléistocènes

Dental eruption sequence and hypsodonty index of a Pleistocene macraucheniid from the Brazilian Intertropical Region

“…Its record is mainly in the Brazilian Intertropical Region (BIR), and it has also been recorded in Mato Grosso State and Venezuela, but these two occurrences of X. bahiense need to be revised (Cartelle and Lessa, 1988;Cartelle, 1999;Salles et al, 2006;Socorro, 2006). Moreover, we do not agree with the nomenclatural action by Guérin and Faure (2004), which assigned X. bahiense Cartelle and Lessa, 1988 as a junior synonym of Macrauchenia patachonica Owen, 1838. First, Guérin andFaure (2004) did not compare their sample from caves in Piauí State with the type material of X. bahiense.…”

“…Moreover, we do not agree with the nomenclatural action by Guérin and Faure (2004), which assigned X. bahiense Cartelle and Lessa, 1988 as a junior synonym of Macrauchenia patachonica Owen, 1838. First, Guérin andFaure (2004) did not compare their sample from caves in Piauí State with the type material of X. bahiense. Second, Guérin and Faure (2004) did not contest any diagnostic features of X. bahiense as originally assigned by Cartelle and Lessa (1988).…”

“…First, Guérin andFaure (2004) did not compare their sample from caves in Piauí State with the type material of X. bahiense. Second, Guérin and Faure (2004) did not contest any diagnostic features of X. bahiense as originally assigned by Cartelle and Lessa (1988). Instead, Guérin and Faure (2004) deemed the observed variation between X. bahiense and M. patachonica species-level variation without properly testing such an assumption.…”

“…Instead, Guérin and Faure (2004) deemed the observed variation between X. bahiense and M. patachonica species-level variation without properly testing such an assumption. Indeed, other studies (e.g., Scherer et al, 2009) do not follow the taxonomic arrangement of Guérin and Faure (2004), and further phylogenetic studies of Schmidt and Ferrero (2014) and Forasiepi et al (2016) refuted the idea by revealing consistent morphological features that differ between the two monospecific genera.…”

Proterotheriidae and Macraucheniidae (Litopterna, Mammalia) from the Pleistocene of Rio Grande do Sul State, Brazil

“…Later records of macraucheniids from states of Bahia, Pernambuco, Ceará, Paraíba and Rio Grande do Norte were also assigned to X. bahiense (Oliveira et al, 1989;Bergqvist, 1993;Bergqvist et al, 1997). Recently, Guérin & Faure (2004) suggested that this taxon could be a synonym of Macrauchenia patachonica, including new material from Piauí State. Nevertheless, some authors (e.g., Socorro, 2006) do not follow this proposition, considering X. bahiense as a valid taxon.…”