Aquilops

Aquilops
Name	Aquilops
Suborder	Ceratopsian
Name Translation	American Eagle Face
Period	108 million years ago
Location	Montana, U.S.A
Diet	Herbivore
Size	61 cm(2 feet)
Date of Discovery	2014

Aquilops was a ceratopsian from early Cretaceous North America. The dinosaur was discovered in 1997 in Southern Montana, but was first named and described in 2014. It's name translates to 'Eagle face'.

The skull is 84.2 mm long. The holotype is possibly not from a full-grown individual. A comparison with related species indicates it might have been at 60% of its adult length. Wedel estimated the total body length of Aquilops at 60 cm and its weight at 1.5 kg.

The authors established some unique traits. The rostral, the bone core of the sCnout beak, curves downwards and has an arched keel on its top with a bump on the front. In front of the tooth row the upper jaw rim is over its total length concave in side view. The skull opening, the antorbital fenestra, is twice as long as it is tall and has a pointed rear, below the eye socket.

Classification

Aquilops was placed in the Neoceratopsia. A cladistic analysis showed that it was positioned rather basal, below Leptoceratops in the evolutionary tree, with only Liaoceratops being more basal. A more derived position, e.g. as a leptoceratopsid or a protoceratopsid, was less likely; it was improbable that it was a ceratopsoid. The fact that the holotype was a subadult might have distorted these results because juvenile individuals often show basal traits. However, after correcting for traits that might change during ontogeny, the resulting tree was basically the same. The ceratopsians more derived than psittacosaurids, called neoceratopsians, evolved in Asia: the presence of a basal neoceratopsian in North America was seen as an indication for a late Early Cretaceous migration event, the ancestors of Aquilops invading from Asia. Two later such events would have occurred in the early Late Cretaceous.