Los carcarodontosauridos dominan el mundo en el XV EJIP

Concavenator vuelve a pasearse por un congreso, esta vez en el XV EJIP que tuvo lugar los pasados días 19-22 de Abril. Esta vez, el trabajo presentado por Elena Cuesta fue la paleobiogeografía de los carcardontosauridos y el rol que ocupa Concavenator en el entendimiento de la misma.

Históricamente, los carcarodontosauridos habían sido atribuidos exclusivamente al continente Gondwánico. Sin embargo, los últimos descubrimientos en Asia, Norte América y Europa (incluyendo Concavenator) han hecho replantearse la distribución de este grupo. Trabajos sobre paleobiogeografía del Mesozoico establecen un importante intercambio faunístico entre Gondwana y Laurasia durante el Jurásico Superior y el Cretácico Inferior a través del archipiélago Europeo. Es en este punto, donde los nuevos resultados de Concavenator como un carcharodontosaurido basal son claves como pieza de este puzzle biogeográfico, debido a su posición tanto paleobiogeográfica como temporal.

Aquí os dejamos el resumen del trabajo:

Carcharodontosauridae is a monophyletic group with a wide distribution around Laurasia and Gondwana during the Cretaceous. Historically, the group was considered exclusive of Gondwana (e.g.; Novas et al., 2005; Coria & Currie, 2006). However, posterior discoveries of carcharodontosaurids in Europe and Asia (e.g. Brusatte et al., 2009; Ortega et al., 2010; Gasca et al., 2014) involve that the group have a wider palaeogeographical distribution. The temporal range is Barremian (Early Cretaceous) to Turonian (Late Cretaceous). Concavenator is, hitherto, the earliest carcharodontosaurid genus defined during the Cretaceous. However, incomplete and fragmentary material from the Late Jurassic of Tanzania, has been suggested as carcharodontosaurid material (Rauhut, 2011). Therefore, a Late Jurassic origin of the carcharodontosaurids is suggested. Although the last known carcharodontosaurid genus recorded is Shaochilong (Turonian), there is younger material (Campanian-Maastrichtian) from an indeterminate carcharodontosaurid from found in Brazil (Fernandes de Azevedo, et al., 2013). Therefore, the complete record of carcharodontosaurids, including fragmentary and indeterminate material, ranges from the Late Jurassic to the Campanian-Maastrichtian around Laurasia and Gondwana, being its best documented record from the Aptian.
Historically, the final breakup of the supercontinent Pangea during the Mesozoic implied recognizing a severe distinction between the Laurasian territories (North America, Europe and Asia) and Gondwanan landmasses (South America, Africa, Madagascar, India, Antarctica and Australia). However, the number of discovering about Gondwanan lineages in Laurasia have increased in recent years (e.g. Sereno et al., 2004; Brusatte et al., 2009; Ortega et al., 2010; Gasca et al., 2014; Tortosa et al., 2014). The presence of these faunas in Laurasia has supposed alternative hypotheses to explain this occurrences (e.g Sereno et al., 2004; Ezcurra & Agnolín, 2012; Dunhill et al., 2016). Based on Ezcurra & Agnolín (2012), during the earliest Cretaceous (Berriasian-Hauterivian), Europe presents significant biogeographical affinities with Gondwana by faunal interchanges via Africa. Posteriorly, Europe becomes isolated from Africa and a biotic interchange was exclusively performed between Europe and Asia during the Aptian-Albian and Cenomanian-Santonian. The palaeobiogeographic distribution of carcharodontosaurids matches with the hypothesis proposed by Ezcurra & Agnolín (2012). The origin of the clade is situated in Africa during the Late Jurassic (Rauhut, 2011; Cziski-Sava et al., 2016) and posteriorly, during the earliest Cretaceous, a biotic interchange of the carcharodontosaurid faunas was displaced to the European territories. The position of Concavenator as a basal carcharodontosaurid (Cuesta, 2017) supports the hypothesis of this European faunistic interchanges. Posteriorly, during the Albian-Aptian, a coalescence between Asia and Europe allows the dispersion of the group in the Asian continent. The Asian record of Carcharodontosauridae is frequent during this period (e.g. Buffetaut & Suteethorn, 2012; Mo et al., 2014). The interchange between Asia and North America is produced during all Mesozoic, and the occupation of the Asian territories during Aptian-Albian, favoured the presence of Acrocanthosaurus in North America. Finally, Carcharodontosaurinae has been widely accepted as an endemic subclade of Gondwanan carcharodontosaurid (e.g. Brusatte & Sereno, 2007; Novas et al., 2013) (Fig. 2). The decrease of carcharodontosaurids in Laurasia landmasses during the Late Cretaceous would be associated to the ecological release of tyrannosauroids of these areas during the end of the Cretaceous (Brusatte et al., 2009; Zanno & Makovicky, 2013).

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Más información:

• Cuesta, E. 2017. Palaeobiogeographic implications of Concavenator corcovatus (Theropoda, Dinosauria) from Las Hoyas fossil site (Cuenca, Barremian). In: Barrios de Pedro, S. et al, A Glimpse of the Past. Abstract Book of the XV Encuentro de Jóvenes Investigadores en Paleontología/XV Encontro de Jovens Investigadores em Palentologia, Lisboa. 125-129.