A new occurrence of the ichnogenus Brachychirotherium:
implications for the Triassic-Jurassic mass extinction event
Abstract--New excavations at the Friendship Home locality in the
Exeter Township Member of the Passaic Formation have uncovered numerous
vertebrate footprint horizons. This site contains the palynologically-defined
Triassic-Jurassic boundary. Ichnotaxa discovered here include Brachychirotherium
spp., Grallator spp., Rhynchosauroides sp., and two proposed
new taxa. The discovery of abundant Brachychirotherium within four meters
of the Triassic-Jurassic boundary is believed to be especially significant
since this ichnogenus is unknown in post-Triassic strata worldwide. This
and other ichnological data from the study site support the hypothesis
of an abrupt extinction event at the Triassic-Jurassic boundary.