Megacricetodon minor (DAAMS & FREUDENTHAL, 1988)

Hír, J., 2013, Early and Middle Miocene (MN 5 - MN 6) transitional rodent fauna from Litke (North Hungary, Nógrád County), Fragmenta Palaeontologica Hungarica 30, pp. 101-137 : 121-122

M. minor is a frequent element of the Middle Miocene rodent faunas and it has a long chronological range in Central Europe (from MN5 to MN9 zone). There are different opinions in the literature on the evolutionary trends of the M. minor populations. WESSELS & REUMER (2009) refused any apparent trend in size and in morphology and their opinion is that the small difference in average sizes in the Sandelzhausen molars compared to the type specimens from Sansan does not warrant a separate taxonomical position .

KÄLIN (1997) and KÄLIN & KEMPF (2009) distinguished the following three “taxa” within M. minor sensu lato.

1. M. cf. minor or Megacricetodon sp. is “very small”. After the above cited authors it represents a new, yet unnamed species which is characteristic in the period approximately 15.2–14.4 MY ago and corresponds most probably to the species “ M. minor small form” described by HEISSIG (1997). Up to now this form has not been found in the Carpathian Basin.

2. The typical, relatively large sized M. minor (e.g. Sagentobel, Unterneul 1a, Rümikon, Göttschlag, Ziemethausen, Helsinghausen in the Upper Freshwater Molasse). The known populations in the Carpathian Basin are Hasznos, Sámsonháza, Felsőtárkány – Felnémet 2/3, 2/7. The Litke material is referable to this form, although the molars from Litke have some special characters: occurrence of hyperdeveloped paracone posterior spur in M1-M2, occurrence of lingual cingulum from the anterocone to the hypocone in M1, 100% unicuspid (undivided) and relatively narrow anteroconid in m1. The two latter markers are definitely plesiomorph characters and those are known in the Early Aragonian Megacricetodon primitivus populations. It was described, e.g. from Buñol ( DAAMS & FREUDENTHAL 1974), Aliveri ( KLEIN HOFMEIER & DE BRUIJN 1988), La Retama (ÁLVAREZ SIERA et al. 2006), Pico de Fraile (RUIZ SANCHEZ et al. 2013), Artesilla ( OLIVER PÉREZ et al. 2008).

3. M. aff. minor is a small form, which appeared in the MN8 zone (Anwil). Its relation to other small-sized Megacricetodon taxa ( M. debruijni , M. minutus ) and its possible synonymy is still under discussion. This Late Astaracian – Early Vallesian Megacricetodon form is known in the Carpathian Basin from Mátraszőlős, Felsőtárkány 1, 2, 3/2, 3/10 but they originally were classified as M. minor , M. minutus or M. cf. minutu s.

As a conclusion the Litke Megacricetodon material can be classified as

Megacricetodon minor with the remark that it has some archaic characters.