Thursday, June 22, 2023

[Paleontology • 2023] Skull of A dromaeosaurid Dinosaur Shri devi from the Upper Cretaceous of the Gobi Desert suggests Convergence to the North American forms


Shri devi Turner, Montanari & Norell, 2021

Artwork by Jakub Zalewski
 
Numerous dromaeosaurid taxa recovered from the Upper Cretaceous strata of the Gobi Desert raise questions over niche partitioning among closely related species. Here, I describe a dromaeosaurid specimen from the Baruungoyot strata of the Khulsan locality, containing a partial skull in close association with the left hind limb. The material can be referred to the velociraptorine Shri devi, until now known only from a single specimen lacking a skull, collected from the same site. The referral is based on the apomorphic morphology of the pes, including the highly hypertrophic ungual of the second digit and details of the metatarsus. The skull of S. devi confirms its close affinities with Velociraptor mongoliensis, but shows distinctive features among Velociraptorinae, including a short antorbital fenestra, a Z-shaped maxillo-jugular suture, a distinct labial ridge above the supralabial foramina row of the maxilla, and the posterior position of the last maxillary tooth. The skull of S. devi is slender, but relatively short when compared to other velociraptorines, suggesting convergence to the North American eudromaeosaurians. The Baruungoyot strata with S. devi represent less arid conditions than the aeolian Djadokhta strata yielding V. mongoliensis, supporting earlier observations linking the elongation of the dromaeosaurid snout with the environment.

Key words: Dinosauria, Theropoda, Dromaeosauridae, convergence, Cretaceous, Mongolia, Gobi Desert.

Dromaeosaurid dinosaur Shri devi Turner, Montanari, and Norell, 2021 (ZPAL MgD-I/97) from the Upper Cretaceous, Khulsan, Ömnögovi, Gobi Desert, Mongolia. Specimen prior to the preparation work (A1), and the 3D model of the skeleton, based on the CT and surface scanner data, with elements arranged as originally found (A2).

Reconstruction of the dromaeosaurid dinosaur Shri devi Turner, Montanari, and Norell, 2021, based on ZPAL MgD-I/97 and MPC-D 100/980.
A. Skull; missing elements reconstructed on the base of Velociraptor mongoliensis Osborn, 1924 (MPC-D 100/25 and MPC-D 100/54).
B. Whole body silhouette with known remains of the holotype and referred material. Silhouette based on V. mongoliensis drawn by J.A. Headden (Wikimedia Commons CC-BY-3.0).

Artistic post-mortem reconstruction of the Shri devi Turner, Montanari, and Norell, 2021,
individual represented by a specimen ZPAL MgD-I/97 before its final burial.
Artwork by Jakub Zalewski.

    


Łukasz Czepiński. 2023. Skull of A dromaeosaurid Dinosaur Shri devi from the Upper Cretaceous of the Gobi Desert suggests Convergence to the North American forms. Acta Palaeontologica Polonica. in press. DOI: 10.4202/app.01065.2023