New contribution to the palaeoichnology and taphonomy of the Ahníkov fossil site, Early Miocene, Most Basin (the Czech Republic)

Abstract

The material of Machichnus regularis and Machichnus multilineatus was re-examined with respect to the potential tracemaker. New characters were defined for M. multilineatus – scratch profile with flat horizontal bottom and undulated microrelief of scratches. Based on these characters and additional information, both previously suggested tracemakers (beavers and porcupines) are rejected and a new one – a large squirrel is proposed. The squirrel origin of gnawing traces is additionally supported by actuopalaeontologic study on gnawing behaviour of recent red squirrels. On this basis, squirrels are recognized as overlooked but important taphonomic agents in Late Cenozoic assemblages. The tracemaker of M. regularis was not unambiguously recognized, but a connection with smaller squirrel or aplodontid species seems probable.

First remains of Diplocynodon cf. ratelii from the early Miocene sites of Ahníkov (Most Basin, Czech Republic)

“…According to Mach et al (2017), both names (Ahníkov and Merkur-North) used for this palaeontological site are synonymous and the authors therefore referred to it as Ahníkov/Merkur Mine. However, we prefer to use just the name Ahníkov (for more details see Ekrt et al 2016).Ahníkov is located between the cities of Kadaň and Chomutov, more specifically 2 km SW from the Zelená village in the westernmost part of the Most Basin (Fig. 1).…”

“…1). The site was discovered in the 1960s during drill cores prospection and the geological profile was exposed in the 1980s (Čtyroký et al 1964a, b;Bůžek et al 1988;Dvořák et al 2010;Ekrt et al 2016).The Most Basin is the largest of the five Cenozoic freshwater basins along the Ohře/Eger Graben (Rajchl et al 2009). The bedrock of the Most Basin consists of Proterozoic metamorphic rocks, covered by Carboniferous sediments and volcanic rocks; these are subsequently overlaid by Cretaceous marine sediments (Mach et al 2014).…”

“…According to Mach et al (2017), both names (Ahníkov and Merkur-North) used for this palaeontological site are synonymous and the authors therefore referred to it as Ahníkov/Merkur Mine. However, we prefer to use just the name Ahníkov (for more details see Ekrt et al 2016).…”

“…1). The site was discovered in the 1960s during drill cores prospection and the geological profile was exposed in the 1980s (Čtyroký et al 1964a, b;Bůžek et al 1988;Dvořák et al 2010;Ekrt et al 2016).…”

Early Miocene small mammals from MWQ1/2001 Turtle Joint (Mokrá-Quarry, South Moravia, Czech Republic): biostratigraphical and palaeoecological considerations

“…Early Miocene fossil mammal assemblages are quite frequent in Central Europe, however, only nine localities are known from the territory of the Czech Republic (Cicha et al 1972;Fejfar, 1974Fejfar, , 1990Fejfar & Roček 1986;Fejfar & Kvaček, 1993;Fejfar et al 2003;Ekrt et al 2016). The older ones come from the early Burdigalian deposits of the main brown coal seam of Ahníkov/Merkur Mine (early MN3a) and the limestone quarry of Tuchořice (MN3b), both located in the Most Basin (Ohře/Eger Graben, NW Czech Republic) and of early Burdigalian (Eggenburgian) in age.…”