Measurements of bite traces on bones

Carnivores make traces on bones with their teeth when feeding. A true
predatory bite trace (predichnia) forms when a predator catches and kills
its prey or attempts to do so. Both predators and scavengers may leave
their non-predatory feeding traces during postmortem food processing.
Despite the interpretative uncertainties as to the ethology such
ichnofossils may represent, the bite traces have been traditionally
classified as predichnia – traces of predation. Previously, there was no
alternative ethological category available for workers to classify them.
The present paper fills that gap and describes tooth-made ichnofossils
from the continental Upper Triassic Grabowa Formation of southern Poland.
It discusses modes the serration and striations might have formed along
Linichnus edges, potential makers of the trace fossils, feeding strategies
and food-processing behaviors the ichnites may represent. All the bite
traces are thought to act as a record of carnivorous behaviors and are
classified as sarcophagichnia, a new ethological category (traces of
feeding on a body). Finally, all of the studied bite traces were likely
inflicted postmortem and are classified as necrophagichnia (traces of
feeding on an already dead body), most likely produced by scavengers in
the studied cases. Data on recent carnivores links these ichnites with
postmortem food processing behaviors, like dismembering and defleshing.
Scavenging could, in fact, have been a preferred carnivorous feeding
strategy in the seasonal Norian climate of the area. Dry seasons could
have perhaps increased vertebrate mortality rates and provided plenty of
carcasses for carnivores to feed on.