TheLeporidDatum: a lateMiocene biotic marker

Abstract

Although Lagomorpha (rabbits, hares and pikas) have a long evolutionary history in Eurasia and Africa, including primitive genera of Eurasia historically considered assignable at the family level to Leporidae, the predecessors of modern rabbits were absent throughout this vast region for most of the Miocene until late in that epoch. During the early and middle Miocene, crown group Leporidae differentiated in North America, then dispersed to northern Asia in the late Miocene around 8 Ma (million years before present) and afterward. They then spread widely and apparently rapidly throughout Eurasia, reaching South Asia by 7.4 Ma and penetrating Africa about 7 Ma. The apparently abrupt introduction of Leporidae is a striking late Miocene event that we call the Leporid Datum. Perceived in terms of biochrons, the Leporid Datum includes localities in Europe and western Asia of late MN11 (Mammifères Néogènes system) age and younger, and precedes by less than one million years the Bahean‐Baodean land mammal age boundary in China. The late Miocene spread of Leporidae throughout Eurasia was a successful invasion in terms of the numerous occurrences and abundant fossils preserved. Where dating is sufficiently robust, the Leporid Datum is late Miocene, nowhere certainly more than ∼8 Ma. In contrast to this sudden and widespread invasion, rare older finds suggest two possible refinements to this scenario: stem lagomorphs close to modern Leporidae may have lingered into the middle Miocene of Eurasia, or an independent, unsuccessful leporid invasion from North America may have preceded the 8 Ma datum. The Leporid Datum marks an important palaeoecological event for the Old World and complements the significance of molecular dates for origins of modern genera.

New Late Miocene Alilepus (Lagomorpha, Mammalia) from Eastern Europe - a new light on the evolution of the earliest Old World Leporinae

“…4) At least one, probably north-Asiatic lineage, should lead to European Alilepus populations (cf. e.g., Jin et al 2010, Flynn et al 2014. Although A. annectens most likely belongs to this northern branch of Alilepus, taxonomical and palaeobiogeographical data presented here indicates that it cannot be linked directly with A. laskarewi.…”

“…Whereas MN12 Old World records of Leporinae are relatively rare, and mostly limited to Europe, MN13 ones are relatively more common and available throughout the Old World. Only few, very fragmentary findings, date an appearance of advanced leporids in the Old World undoubtedly before MN12 (Flynn et al 2014). There are also a few, still questionable fossil occurrences suggesting that leporids were present in Europe prior to MN11, however in many of these cases the relation of the leporid findings with the accompanying faunal assemblages is not clear and such findings need further evaluation of both age and taxonomy (see Flynn et al 2014).…”

“…The new Ukrainian and Moldovan leporids in the context of the most ancient Old World records (Flynn et al 2014). Whereas MN12 Old World records of Leporinae are relatively rare, and mostly limited to Europe, MN13 ones are relatively more common and available throughout the Old World.…”

“…Four Archaeolaginae and Leporinae genera are recorded: 1) Alilepus: proven from MN12 (Flynn et al 2014 (López Martínez et al 2007, Čermák & Wagner 2013.…”

“…In the context of dispersal scenarios of leporids into Eurasia as proposed by Flynn et al (2014), the relatively early presence of Alilepus in Eastern Europe can be explained as a result of limited dispersal prior to the successful main late Miocene influx. Considering the general features of A. laskarewi in the palaeobiogeographic and biochronologic context of the Asiatic and North American leporid fossil record, the roots of the lineage leading to A. laskarewi can be traced to near the Clarendonian/Hemphillian boundary, to the phyletic proximity of A. hibbardi stock.…”