FOOPRINTS COMPARABLE TO ROEPICHNUS AT THE PEHUEN CO PALEOICHNOLOGICAL SITE (LATE PLEISTOCENE), BUENOS AIRES PROVINCE, ARGENTINA

FEOLA, SILVERIO; MANERA, TERESA; MELCHOR, RICARDO

Congreso; 4th Paleontological Virtual Congress; 2023

Diverse bird tracks have been well documented at the Pehuen Co Paleoichnological Site (YPPC), Buenos Aires Province, Argentina, including those assigned to the ichnospecies Phoenicopterichnum pehuencoensis, Charadriipeda isp., Gruipeda isp. and Aramayoichnus rheae. A relatively recent find at the YPCC indicates the presence of bird tracks with three digit impressions arranged in a trackway composed of four footprints. These footprints are on average of 14.5 cm long and 12 cm wide, and show an incipient trace of webbing. The central digit (III) imprint is longer than the rest, and exceeds the impression of the web, while the lateral digits are shorter, usually curved towards the front of the track, and form an interdigital angle (II-V) of ~80º. The above characteristics largely conform to the ichnotaxobases defined for the ichnogenus Roepichnus although the footprints from the YPCC are slightly smaller in size. Despite the fact that Roepichnuswas defined from tetradactyl footprints, the hallux impression is not always preserved and consequently, occasionally only the impression of three digits can be observed. Therefore, themorphological characteristics of the four YPPC prints are very similar to those of Roephicnus, indicating that they belong to this ichnotaxon. The morphological characteristics and sizes of the studied footprints suggest a group of Anseriformes birds of the Anatidae family belonging to the genus Cygnus as possible producers.