Megacricetodon minutus Daxner, 1967

Hír, János & Kókay, József, 2010, A systematic study of the middle-late Miocene rodents and lagomorphs (Mammalia) of Felsőtárkány 3 / 8 and 3 / 10 (Northern Hungary) with stratigraphical relations, Geodiversitas 32 (2), pp. 307-329 : 317-318

Megacricetodon minutus Daxner, 1967

MATERIAL EXAMINED. — See Table 12 for data and measurements.

DESCRIPTION

The anterocone of M1 is divided,the anterolophule is short, the protolophule I is developed in one specimen

(2007.123), the mesoloph reaches the labial margin (2007.170, 171), or shows an intermediate level of development (2007.123). Th e anteroconid of m1 is divided, the anterolophulid has a short labial spur in the specimen 2007.172, the mesolophid exhibits an intermediate development, an ectomesolophid-like conelet is found in the molar 2007.172.

COMMENTS

In the original diagnosis (Daxner 1967) the following markers of M1 are noted: small size, undivided anterocone, labial sinus curved forward and occasionally connected with the lingual sinus, lingual cusps wide, labial cusps mesio-distally reduced, mesoloph moderately developed and occasionally connected with the paracone spur. But the original material consists of only two M1 (holotype from Inzerdorf and paratype from Vösendorf, Austria) and one M2. In the Carpathian Basin, a M. minutus population was found at Borsky Sväty Jur in Slovakia ( Joniak 2005), which is abundant and represents the morphological variability of M. minutus . In this population, three morphotypes of M1 anterocone are equally found: well splitted, slightly splitted and undivided are equally. In the same way, the mesoloph of M1 may be long, moderately developed or short (or absent). On the basis of morphological characters, we cannot distinguish the species M. minor and M. minutus . Th e useful markers are the slightly smaller mean dimensions of M. minutus . Furthermore a very similar taxon: Megacricetodon aff. minor was described from MN 7-8 faunas of the Northern Alpine Voreland Basin ( Fahlbusch 1964; Engesser 1972; Bolliger 1992, 1994; Prieto 2007). Th e mean dimensions of M. minutus from FT 3/2 and 3/10 are among the smallest for M. minor-M. minutus group in Central Europe. Joniak (2005) demonstrated that Megacricetodon debruijni Freudenthal, 1968 is a junior synonym of Megacricetodon minutus . Beyond the above mentioned localities M. minutus was reported from the early Pannonian of Austria:Mataschen, Richardhof- Golfplatz, Bullendorf (Daxner-Höck 2004c).