First Dinosaurs from Saudi Arabia

Abstract

Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (∼75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids – this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.

The distribution of dental features in non-avian theropod dinosaurs: Taxonomic potential, degree of homoplasy, and major evolutionary trends

“…Teeth, and particularly tooth enamel, are robust skeletal elements (Hillson, 2005), and most toothed theropods had 50 or more teeth that were replaced every one to two years (Fiorillo and Currie, 1994;Erickson, 1996). Consequently, theropod teeth are one of the most common fossils in terrestrial Mesozoic formations (e.g., Erickson, 1996;Smith et al, 2005;Blob and Badgley, 2007) and are constantly reported in the literature (e.g., Currie et al, 1990;Rauhut and Werner, 1995;Baszio, 1997;Zinke, 1998;Sankey et al, 2002;Sweetman, 2004;Maganuco et al, 2005;Vullo et al, 2007;Larson, 2008;Casal et al, 2009;Lubbe et al, 2009;Ősi et al, 2010;Han et al, 2011;Sues and Averianov, 2013;Larson and Currie, 2013;Richter et al, 2013;Torices et al, 2015;Kear et al, 2013;Madzia, 2014;Hendrickx and Mateus, 2014a;Cobos et al, 2014;Tavares et al, 2014;Fanti et al, 2014;Brusatte and Clark, 2015;Csiki-Sava et al, 2016;Gerke and Wings, 2016;Alonso et al, 2017;Malafaia et al, 2017a;Avrahami et al, 2018;Frederickson et al, 2018;…”

Hadrosauroid Dinosaurs from the Late Cretaceous of the Sultanate of Oman

“…Although various dinosaur remains have been reported from the Mesozoic of the Arabian Peninsula and the Levant (reviewed in [ 1 ]), including Oman [ 3 , 4 ], no hadrosauroids had so far been reported from that area. More generally, hadrosauroids were previously unknown from the Afro-Arabian plate [ 15 ] (although a possible hadrosauroid pedal phalanx from the Maastrichtian of Angola [ 21 : Fig 17] is worth mentioning).…”

“…The presence of hadrosauroids in Oman, i.e., the north-eastern part of the Afro-Arabian plate, in the Maastrichtian is therefore unexpected. The recently described dinosaurs from Saudi Arabia [ 1 ], of Campanian-Maastrichtian age, are titanosaurid sauropods and abelisaurid theropods and therefore belong to groups that were widespread in Afro-Arabia during the Late Cretaceous. The hadrosauroids from Oman are more difficult to interpret from a paleobiogeographical point of view.…”

“…Although iguanodontians are known from the Early Cretaceous of Africa, the best-known form being Ouranosaurus from Niger [ 11 ], there is no evidence whatsoever that more derived forms such as hadrosaurs evolved in that part of the world. Admittedly, the Late Cretaceous dinosaur record from Afro-Arabia remains scanty, especially for the later part of that period, but what was known so far indicated the prevalence of “Gondwanan” forms such as titanosaurs and abelisaurids, which are known, for instance, from the Maastrichtian phosphates of Morocco [ 23 , 24 ], as well as from Saudi Arabia [ 1 ].…”

“…Very few dinosaur fossils have been reported from the Arabian Peninsula [ 1 ]. From the Sultanate of Oman, the first mention of dinosaur remains was made by Nolan et al in 1990 [ 2 ] based on an indeterminate ornithischian vertebra from the Al-Khod Conglomerate.…”