Temporal range: Late Cretaceous, 70Ma
|Leg bones of the holotype|
†B. gracilicrus Osmólska, 1987
In 1971, a Polish-Mongolian expedition discovered at the Altan Ula IV site, in the Nemegt Basin of Ömnögovĭ province, the remains of a small theropod. The find was in 1982 reported by Halszka Osmólska and considered by her a possible specimen of Saurornithoides. Later she concluded it represented a species new to science.
In 1987, Osmólska named and described the type species Borogovia gracilicrus. The generic name is derived from the fantasy creatures known as 'borogoves' in the Lewis Carroll poem Jabberwocky, part of his Alice's Adventures in Wonderland. The specific name is a combination of Latin gracilis, "lightly built", and crus, "shin", in reference to the elegant build of the lower leg.
The holotype specimen, ZPAL MgD-I/174, was found in the Nemegt Formation, dating from the early Maastrichtian. It consists of two lower legs of a single individual, including fragments of both tibiotarsi, the undersides of both metatarsi and the second, third and fourth toes of each foot.
The tibiotarsi have an estimated length of twenty-eight centimetres. Borogovia is about two meters (6 feet) long, weighing some twenty kilograms (forty-five pounds). The tibiotarsus is very elongated. The third toe is narrow. The second phalanx of the second toe is short. The claw of the second toe is short and relatively flat. Osmólska claimed that the second toe could not be hyperextended and suggested that it had regained a weight-bearing function, compensating for the weakness of the third toe.
- Osmólska, H., 1982, "Hulsanpes perlei n.g.n.sp. (Deinonychosauria, Saurisichia, Dinosauria) from the Upper Cretaceous Barun Goyot Formation of Mongolia", Neues Jahrbuch für Geologie und Paläontologie, Monatschefte 1982(7): 440-448
- Osmólska, H., 1987, "Borogovia gracilicrus gen. et sp. n., a new troodontid dinosaur from the Late Cretaceous of Mongolia", Acta Palaeontologica Polonica 32: 133-150