''Litovoi tholocephalos'' is a
multituberculate mammal indigenous to
Romania
Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...
, then the
Hațeg Island. A part of
Kogaionidae, a lineage otherwise dominated by iron-enamelled insectivores, ''Litovoi'' appears to have had a similar lifestyle, having similar teeth. Different however is its cranial anatomy; this is the first recorded example of a Mesozoic island mammal have reduced its brain size in an insular environment, presumably due to the lack of predators or specialised niche it found itself in. It has one of the smallest brain-to-body ratios seen in derived mammals, although it retains enlarged olfactory bulbs and paraflocculi. Being relatively normal sized for a multituberculate, this showcases that brain reduction is not correlated to allometry.
[Zoltán Csiki-Sava; Mátyás Vremir; Jin Meng; Stephen L. Brusatte; Mark A. Norell (2018). "Dome-headed, small-brained island mammal from the Late Cretaceous of Romania". Proceedings of the National Academy of Sciences of the United States of America. in press. .]
References
{{Taxonbar, from1=Q55390778, from2=Q73166067
Cimolodonts
Cretaceous mammals
Extinct mammals of Europe
Hațeg fauna
Fossil taxa described in 2018