A Lower Cretaceous dinosaur track assemblage from the Taoqihe Formation in Central Heilongjiang, China

An Early Cretaceous dinosaur ichnofauna is reported from the Taoqihe Formation (Aptian-Albian) in Heilongjiang Province, China. The assemblage, which comprises > 70 tracks in 5 trackways, includes parallel sauropod trackways, a toe-trace dominated tridactyl omithopod trackway and elongate tridactyl theropod tracks, the latter tentatively be attributed to swimming activity. The combination of possible swim and walking trackways suggest that they were formed at different times and in different environments. This is the first Lower Cretaceous tracksite reported from Heilongjiang Province with the exception of an historic record of a large pentadactyl track of probable thyreophoran (ankylosaurian) affinity. Ankylosaurian tracks are rare in China, and reported tentatively from only one other location. The dinosaur ichnofauna from the Taoqihe Formation is similar in composition to the skeletal assemblages of the Early Cretaceous Jehol Biota in the nearby Liaoning Province. The new track records are important for better understanding the palaeobiogeography and faunal developments of northeastern China and adjacent Russia.