The Upper Triassic continental deposits of Monte Pisano (Northern Apennines) preserve a high number of tetrapod tracks: some of them are among the most ancient italian records of dinosaurs. In this work we describe a putative, isolated ichnite (the “Agnano track”) from the top member of the Monte Serra Quartzites Formation consisting of a small-sized, tridactyl possible pes impression. Being concave and lying on the sole of a fine-grained arenaceous bed, this feature poses some serious difficulties in order to fully embrace its tetrapod-related origin, although concave hyporeliefs have been recently pointed out (but not investigated) by some authors. If the observed concave hyporelief is not an artefact, it could have been formed during the early phases of the diagenesis by differential compaction of the sandy layer immediately overlying a well-indurated undertrack. After having tentatively interpreted the “Agnano track” as a sort of “second generation” imprint, we emphasize its similarities with the Anomoepus-like group of vertebrate ichnites, thus proposing it could testify the passage of a basal ornitischian dinosaur.
A new record of Triassic dinosaur footprint from Monte Pisano (Northern Apennines, Italy): true or false?
COLLARETA, ALBERTO;FARINA, SIMONE
2015-01-01
Abstract
The Upper Triassic continental deposits of Monte Pisano (Northern Apennines) preserve a high number of tetrapod tracks: some of them are among the most ancient italian records of dinosaurs. In this work we describe a putative, isolated ichnite (the “Agnano track”) from the top member of the Monte Serra Quartzites Formation consisting of a small-sized, tridactyl possible pes impression. Being concave and lying on the sole of a fine-grained arenaceous bed, this feature poses some serious difficulties in order to fully embrace its tetrapod-related origin, although concave hyporeliefs have been recently pointed out (but not investigated) by some authors. If the observed concave hyporelief is not an artefact, it could have been formed during the early phases of the diagenesis by differential compaction of the sandy layer immediately overlying a well-indurated undertrack. After having tentatively interpreted the “Agnano track” as a sort of “second generation” imprint, we emphasize its similarities with the Anomoepus-like group of vertebrate ichnites, thus proposing it could testify the passage of a basal ornitischian dinosaur.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
