Article: A revision of the large lagomerycid artiodactyls of Europe
Large lagomerycids are only known in Europe from the Orleanian of the Loire Basin (France). At least three forms are recognized: Ligeromeryx gen. nov. praestans, Heterocemas? sp. and Lagomerycidae gen. et sp. indet. The genus Lagomeryx is restricted to small European species. If it is hypothesized that apophyseal appendages originated only once among cervoids, then a hypothetical brachyodont ruminant with divergent, supraorbital appendages bearing a small, distal fork which was cast from time to time, could be considered to be not only the common ancestor of lagomerycids and cervids, but also of merycodontines. Nevertheless, there is substantial evidence that appendages were acquired several times, and the possibility that lagomercyids are an entirely independent clade among cervoids is postulated. Heterocemas was the most primitive lagomerycid, having forked protoantlers with a prevalence of ramification by sprouting. The move evolved forms acquired multibranched construction (Ligeromeryx) and later, palmation at the protoantler basis (Stephanocemas and Lagomeryx). Small size, accompanied by a subsequent reduction of the protoantler size, could have been acquired secondarily by Lagomeryx, probably when the lagomerycids filled forest-browsing niches.