The phylogeny of Tetanurae (Dinosauria: Theropoda)

Neovenatorid theropods are apex predators in the Late Cretaceous of North America

“…However, the pace and nature of this transformation has been largely unknown due to a near 70 million year gap in the apex predator record of western North America. Discovery of Siats, a gigantic megaraptoran neovenatorid, in mid-Cretaceous ecosystems, together with new phylogenetic interpretations positing Acrocanthosaurus in a more derived position within Carcharodontosauridae 14,19,29,30 indicate that apex predator guilds of that time were composed neither of relic Jurassic theropod clades nor by early replacement by tyrannosaurids, and that two-step depictions of predator communities are insufficient to describe theropod guild evolution during this interval. Rather, these data indicate that mid-Cretaceous theropod assemblages were taxonomically unique from both prior and subsequent faunas in being composed largely of derived carcharodontosaurians (with subsidiary roles occupied by one or more clades of medium-bodied coelurosaurian) and that, minimally, a trifold characterization of apex predator guild occupancy mirroring the pattern observed in Asia 11,14 is required (Fig.…”

“…To date, carcharodontosaurians are not known to have survived past the Turonian (B92 Ma) on Laurasian landmasses 11,30 and also decline in South America over the same timeframe 34,35 (Fig. 5a).…”

“…Maximum agreement subtrees 68 were calculated in TNT and used to identify labile taxa and common topology among all MPTs. We followed Carrano et al 30 in ad hoc pruning of Poekilopleuron, Streptospondylus and Xuanhanosaurus from consensus trees, although this did not change topology within Allosauria. A recent phylogenetic study posited megaraptorans as basal tyrannosauroids 69 .…”

Theropod teeth from the Middle-Upper Jurassic Shishugou Formation of northwest Xinjiang, China

“…Megalosauridae are medium to large-sized carnivorous tetanurans from the Middle to Late Jurassic of Africa, Asia, Europe, and North America (Carrano et al 2012). These basal tetanurans include the first dinosaur to be formally described, Megalosaurus bucklandii, by William Buckland in 1824 (Naish 2012), and one of the largest Jurassic terrestrial predators, Torvosaurus, known from embryos and adult material from the United States and Portugal (e.g., Britt 1991;Araújo et al 2013;Hendrickx and Mateus 2014b).…”

“…These basal tetanurans include the first dinosaur to be formally described, Megalosaurus bucklandii, by William Buckland in 1824 (Naish 2012), and one of the largest Jurassic terrestrial predators, Torvosaurus, known from embryos and adult material from the United States and Portugal (e.g., Britt 1991;Araújo et al 2013;Hendrickx and Mateus 2014b). Megalosauridae is the sister-clade of Spinosauridae among megalosaurian Megalosauroidea, and includes two sub-families, Afrovenatorinae and Megalosaurinae (Carrano et al 2012). Megalosaurid theropods have received considerable interest over the past years leading to a better understanding of their anatomy, and several taxa from the Middle Jurassic of England and the Late Jurassic of Portugal have been redescribed (i.e., Eustreptospondylus, Magnosaurus, Duriavenator, Megalosaurus, Torvosaurus;Benson 2008Benson , 2009Benson , 2010aBenson et al 2008;Sadleir et al 2008;Hendrickx and Mateus 2014b).…”