Ornithopod and Sauropod Dinosaur Remains from the Maastrichtian Al-Khod Conglomerate, Sultanate of Oman

Abstract

Fieldwork in the Upper Cretaceous (Maastrichtian) Al-Khod Conglomerates in the Sultanate of Oman led to the discovery of a large bone fragment tentatively identified as a partial distal left humerus of a sauropod and an ornithopod dorsal vertebra. The very fragmentary state of preservation of the dorsal vertebra makes specific attribution difficult, but it shows remarkable similarities to the rhabdodontid dinosaurs Rhabdodon and Zalmoxes.

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).…”

“…This could explain the relatively small dimensions of most of the hadrosauroid specimens. On the basis of what is currently known, the dinosaurs from Oman include sauropods, a theropod, a possible rhabdodontid [ 4 ] and the hadrosauroids described in the present paper. If the occurrence of a rhabdodontid is confirmed, this assemblage would be similar to that known from the Transylvanian Island in the Late Cretaceous.…”

“…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. A reconnaissance in the Al-Khod Conglomerate in 1997 by ASS and AFH resulted in the discovery of additional fossil vertebrates [ 3 ], and fieldwork by an expanded team in 1998 yielded further material, including dinosaur, turtle and crocodile remains [ 4 , 5 ]. From 2011 until 2014 the second author returned to the Al Khod area on a regular basis for additional prospecting, which resulted in the discovery of numerous new (though mostly fragmentary) dinosaur remains.…”

First Dinosaurs from Saudi Arabia

“…The combined evidence of testable phylogentic character states and metric similarities, we believe, provides a rigorous basis for our taxonomic assignments, even when reliant upon a few incomplete specimens. This is important because dinosaur material from the Arabian Peninsula and Levant is otherwise limited to isolated traces, or rare assemblages recognized only from non-diagnostic body fossils [3] , [4] and track ways [11] . Given this dearth of co-occurring remains, nothing has yet been gleaned of Arabian dinosaur diversity other than the sympatric presence of indeterminate ornithopods, sauropods, and theropods during the Maastrichtian [3] , [4] .…”

“…Dinosaur fossils are extremely scarce in the Arabian Peninsula and Levant region of the Middle East. Published occurrences include isolated teeth and bones of Cretaceous brachiosaurid (Neocomian) and titanosaurian (Maastrichtian) sauropods from Lebanon [1] and Jordan [2] respectively, indeterminate sauropod limb material from Oman (Maastrichtian [3] ), large theropod postcranial elements from Oman (Maastrichtian [4] ) and Syria (Cenomanian or Turonian/Senonian [5] ), and fragmentary ornithopod (Maastrichtian) remains from Oman [3] and Jordan [6] . The partial skeleton of an enantiornithine bird has also been documented from the Late Cretaceous of Lebanon (Cenomanian [7] ), together with feather inclusions in amber from the Early Cretaceous (Neocomian) of Lebanon [8] and Jordan [9] .…”