The Hartl Formation is a geologic formation in Austria. It preserves fossils dated to the Langhian age of the Miocene period.Hartl Formation at Fossilworks.org
See also List of fossiliferous stratigraphic units in Austria
References
Further reading A. Kroh. 2003. First record of gorgonocephalid ophiuroids (Echinodermata) from the middle Miocene of the Central Paratethys. Cenozoic Research 2(1-2):143-155