Machichnus

Machichnus is an ichnogenus. It was erected by Mikuláš et al. (2006) for shallow, thin, discrete, parallel to subparallel, smooth-bottomed scratches, occurring on bone tissue in small groups or series. According to modern analogues, the series of scratches represent marks of teeth of carnivorous or scavenging reptilians and mammals. Such traces are quite frequent in the fossil record since the mid-Mesozoic, but they have seldom been described in detail. 
The type species/specimen of Machichnus comes from the Miocene of the Czech Republic. In this case, crocodiles are suspect as tracemakers.
"Machichnus" contains three ichnospecies: "Machichnus regularis," "Machichnus multilineatus", and "Machichnus bohemicus." The ichnogenera "Brutalichnus" and "Nihilichnus" were described in the same paper.