NEW DATA ON VERTEBRATE AND INVERTEBRATE TRACE FOSSILS FROM THE LATE TRIASSIC LOCKATONG FORMATION, NEWARK BASIN, PENNSYLVANIA

The Lockatong Formation vertebrate and invertebrate ichnological record has been primarily compiled from only a few classic locations while most of the formation remains relatively unexplored. New investigations at four of the well-known localities, in conjunction with samplings at three recent construction sites have enabled us to expand what is known of these Lockatong ichnofaunas.

The ichnofossils mostly occur in lake-margin settings within the cyclical strata of the Lockatong. Vertebrate tracks found encompass many of the classic Newark ichnotaxa including Apatopus lineatus, Atreipus milfordensis, Brachychirotherium sp., Gwyneddichnium majore, and Rhynchosauroides brunswickii. The ichnogenus Gwyneddichnium occurs abundantly at all seven of the study localities and appears to be emerging as the most common track in the Lockatong. An as yet undescribed small reptilian form, herein referred to as new taxon C, was found at five of the study localities. Although previously unrecognized, this form now appears to be a common component of Lockatong Formation vertebrate footprint assemblages. The fish trace Undichnia sp. was also found at one of the study sites.

Invertebrate burrowing traces found include Bergaueria hemispherica, Cochlichnus sp., Gordia sp., Herpystezoum sp., Planolites sp., Scoyenia gracilis, Spongeliomorpha milfordensis, Treptichnus bifurcus and Treptichnus pollardi. Walking arthropod trackways include Diplichnites triassicus, Diplichnites sp. and Acanthichnus alternans. Invertebrate resting traces Lockeia siliquaria, Rusophycus sp. and some possible examples of Selenichnites also were found. Enigmatic grazing traces, irregular burrowing networks and other possible resting traces remain uncategorized as the investigation continues.