''Bolong'' (meaning "Bo's dragon") is a genus of iguanodontian dinosaur known from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

-age Yixian Formation of western

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. It lived about 125 million years ago in the earliest

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

Discovery and naming

It was named by Wu Wen-hao, Pascal Godefroit and Hu Dong-yu in

2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...

. The type species is ''Bolong yixianensis''. The genus name is derived from the names of the brothers Bo Hai-chen and Bo Xue, who helped uncover it, and the Mandarin word 龍 ''lóng'' "dragon". The specific epithet refers to the Yixian Formation where it was found. The holotype fossil, YHZ-001, consists of a highly compressed skull with lower jaws from which a middle portion is missing. In 2013 a second specimen (ZMNH-M8812) was described consisting of an almost complete skeleton of a very young animal. It was found by a farmer near the village of Xitaizhi in Inner Mongolia.

Description

''Bolong'' was a relatively small animal with an estimated length of four meters and a weight of 200 kilograms. The head is convex and fairly stocky with powerful mandibles. The teeth are relatively large. Autapomorphies that have been established are a cavity at the interface of the lacrimal bone, the maxilla, the backwards branch of the prefrontal bone, consisting of a front-to-rear depth cavity above the edges of the eye socket, the lower protrusion of the predentarium extending rearwardly parallel to the lower edge, the interface of the predentarium that occupies less than two-thirds of the height of the dentarium so that the front tip of the dentarium protrudes a third above the predentarium, and that the teeth in the maxilla have dental crowns of which the main ridge bends at the tip of the tooth. A second autapomorpohy was identified based on the second specimen: the inside of the maxillary teeth are thickened and enclosed from the front and rear cutting edges and is divided in half by a striking vertical ledge.

Phylogeny

The describers placed ''Bolong'' in Hadrosauroidea. It would have been one of the most

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hadrosauroids found in Asia.

References

Early Cretaceous dinosaurs of Asia Yixian fauna Iguanodonts Fossil taxa described in 2010 Taxa named by Pascal Godefroit Ornithischian genera {{ornithopod-stub