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Any of various herbivorous ornithischian dinosaurs of the family Hadrosauridae of the Cretaceous Period, having a broad toothless beak, numerous teeth in the back of the jaw, a stiff tail, and sometimes a crest on the head. Also called duckbill, duck-billed dinosaur, hadrosaur.

[From New Latin Hadrosauridae, family name, from Hadrosaurus, type genus; see hadrosaurus.]

had′ro·saur′id adj.
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References in periodicals archive ?
(2012a): Osteology of the basal hadrosauroid Eolambia caroljonesa (Dinosauria: Ornithopoda) from the Cedar Mountain Formation of Utah.
The apex of the neural spine is strongly convex and posteriorly placed as in Iguanodon (Norman, 1980), but unlike other basal iguanodonts such as Iguanacolossus, Mantellisaurus and Ouranosaurus and hadrosauroids such as Bactrosaurus and Tanius, where the apex of the neural spine is gently convex and there is a slight embayment between the apex and the posterior edge.
The profile of Delapparentia differs slightly from Barilium (Norman, 2011a), with its gently convex dorsal margin, and fromMantellisaurus (Norman, 1986), with its dorsal margin straight in the central portion of the body but convex dorsal to the preacetabular notch, and differs clearly from basal iguanodonts such as Iguanaeolossus (McDonald et al., 2010b), Iguanodon (Norman, 1980) and Ouranosaurus (Taquet, 1976), with a clearly convex dorsal edge, and from hadrosauroids such as Gilmoreosaurus or Corythosaurus (McDonald et al., 2010b: fig.
A basal hadrosauroid, the find included partial skull bones, several vertebrae and fragments of the ribs.
In this paper, the hadrosauroid are considered as the group of iguanodontoid dinosaurs more closely related to Parasaurolophus than to Iguanodon (sensu Sereno 1986, 1998; You et al., 2003).
The hadrosauroid fauna of the latest Maastrichtian in the Ibero-Armorican Island is significantly diverse and palaeobiogeographically related to other Laurasian taxa; at least five different hadrosauroids are known, none of which is small in size (Pereda-Suberbiola et al, 2009b; Prieto-Marquez et al, 2013; Cruzado-Caballero et al., 2014)
In addition, Lano has yielded a single tooth belonging to an indeterminate hadrosauroid (Pereda Suberbiola et al., 2003).
It is one of the few hadrosauroid remains from the Late Maastrichtian of Europe found in marine environments, and the first one described from sublittoral deposits in the Iberian Peninsula (Pereda-Suberbiola et al., in press).
The new age assignments do not have significant implications for the temporal distribution of rhabdodontid and hadrosauroid dinosaurs, since the ornithopod-bearing localities discussed in the present work (Perauba-Figuerola, and Els Nerets and L'Espinau, respectively) fall within the time interval expected for each group in the region.
(2014): The hadrosauroid record in the Maastrichtian of the eastern Tremp Syncline (northern Spain).
Only a few teeth can be included within other ornithopod morphotypes that resemble hadrosauroid crowns (16 specimens), and one fragment of a crown shows features similar to Rhabdodontidae.
(2005): A new primitive hadrosauroid dinosaur from the Early Cretaceous of Inner Mongolia (P.