Pronunciation: PLEH-see-o-HAH-dros
Meaning: Near hadrosaurid
Author/s: Tsogtbaatar et al. (2014)
Synonyms: None known
First Discovery: Ömnögovi, Mongolia
Discovery Chart Position: #887
Plesiohadros djadokhtaensis
The Djadokhta Formation at Mongolia's Flaming Cliffs was discovered by Roy Chapman Andrews in the 1920s and has been intensely probed for almost a century since then. It's been most generous in yielding fossils belonging to Pinacosaurus (Ankylosauria), Protoceratops (Ceratopsia), Oviraptor, Saurornithoides and Velociraptor (Theropoda), and even dinosaur eggs and nests. But apart from some infant specimens that Perle and Barsbold mentioned in a brief note in 1983, a member of Ornithopoda had remained elusive until Khishigjav Tsogbaatar and colleagues announced Plesiohadros in 2014.
Plesiohadros is the first Campanian-aged Mongolian member of Hadrosauroidea -- a family of ornithopods known colloquially as "duck-bills" -- and the first new member of this group named from any Mongolian Formation in three decades. Its known remains are a long way short of a complete skeleton. Still, from the fossils available, palaeontologists reckon a total length of around ten meters and a mass of two tons are fair estimates, making this "near hadrosaurid" the largest critter in its ecosystem.
Plesiohadros is the first Campanian-aged Mongolian member of Hadrosauroidea -- a family of ornithopods known colloquially as "duck-bills" -- and the first new member of this group named from any Mongolian Formation in three decades. Its known remains are a long way short of a complete skeleton. Still, from the fossils available, palaeontologists reckon a total length of around ten meters and a mass of two tons are fair estimates, making this "near hadrosaurid" the largest critter in its ecosystem.
(Near-hadrosaurid from the Djadokhta)Etymology
Plesiohadros is derived from the Greek "plesios" (near) and "Hadros" (thick, bulky, stout), in reference to its close proximity to Hadrosauridae (the "heavy lizards").
The species epithet (or specific name), djadokhtaensis, is derived from "Djadokhta" (the formation in which it was discovered) and the Latin "-ensis" (from).
Discovery
The remains of Plesiohadros were discovered at Alag Teeg in the Djadokhta Formation, 3km north of Tögrögiin Shiree, Ömnögovi (southern Gobi) Aimag (Province), Mongolia. The Holotype (MPC-D100/745) is a partial skull and lower jaw, some neck vertebrae, a hyoid (a bone that anchors the tongue), and some hand and finger bones. Referred material (MPC-D100/751) from the same locality as the holotype includes a tibia (shin), fibula (calf), an astragalus (ankle), and some foot and toes bones.
