Hoplitomericidae (Ruminantia, Late Miocene, central-southeastern Italy): whom and where from?

Hoplitomerycidae is a monogeneric family that contains the nominal genus Hoplitomeryx Leinders, 1983, currently represented by six species. Fossils of the hoplitomerycids are found in Lower Tortonian coastal tidal-flat layered calcarenites at Scontrone, in Abruzzo (central Italy), as well as in karstic fissure fillings, supposedly of Messinian age, in the Gargano Promontory, Apulia (south-eastern Italy). Hoplitomerycids are endemic ruminants. Their remains are found associated with bones of many other vertebrates which indicate the existence of a vast territory, the so called Abruzzo-Apulia Platform, that was isolated from the nearest mainland at least from the Early Oligocene up until the latest Miocene. A recent cladistic analysis showed that the classification of the hoplitomerycids in Cervoidea, which currently enjoys vast popularity, is not justified. The family is closer to bovids, antilocaprids and giraffids, but it also shows characters that suggest that the family probably stemmed from a primitive ruminant stock somewhere at the basal divergence of Pecora. Which is consistent with geological evidence showing that 29 Ma a land-bridge connected the Abruzzo-Apulia Platform with the Balkans across the Adriatic Sea, approximately where the Tremiti islands are today. The present study intended to reconnect to the results of the cladistic analysis and to extend them in the attempt to track down the possible ancestors of Hoplitomerycidae. The family expectedly radiated developing autapomorphic homoplasies that make the search quite harduous. Nonetheless, it still preserves primitive, leftover characters relating it to Oligocene taxa, presumably gelocids, dispersed in what now is Anatolia. Current recostructions of the Early Oligocene paleogeography of the eastern Mediterranean show that the Abruzzo-Apulian Platform was connected via the cross-Adriatic land-bridge to the Balkans, Anatolia and by that way also to middle and central Asia and central-eastern Europe. These are the potential source areas of the ancestors of Hoplitomerycidae.