Unusual sauropod tracks in the Jurassic-Cretaceous interval. Cameros Basin (Burgos, Spain).

FIDEL TORCIDA; IGNACIO DÍAZ MARTÍNEZ; RUBÉN CONTRERAS; PEDRO HUERTA; DIEGO MONTERO; VICTOR URIÉN

JOURNAL OF IBERIAN GEOLOGY

SERVICIO PUBLICACIONES

Lugar: Madrid; Año: 2015 vol. 41 p. 141 - 154

1698-6180

The 5.6 km Las Sereas site includes at least 14 ichnological outcrops, in the Lara area, southwest Burgos Province. En Las Sereas 7 se han documentado 67 icnitas de dinosaurios, identificadas como theropod and sauropod trackways occur in shallow carbonates of lacustrine environment. Sauropod trackways have intermediate-gauge and low heteropody, and show different anatomical features to other tracks found in the ichnological record, especially in the disposition and orientation of pes digits. They are similar to Polyonyx from the Middle Jurassic of Portugal. However, since they do not preserve reliable manus data they are classified as aff.Polyonyx. The three sauropod trackways are related to the same kind of trackmaker. They differ from each other only in size, and gregarious behavior has not been detected. Analysis of these trackways reveals changes in travel direction even when there are few tracks in each sequence. At the Las Sereas 7 tracksite, the pace length (PL), width of the angulation pattern (WAP) and the WAP/PL ratio and depth analysis via photogrammetry show a direction change in two sauropod trackways. This tracksite and that at La Pedraja, are unique in the Tithonian-Berriasian interval of the Iberian Peninsula that occur in a lacustrine environment. This could be indicate a relationship between the diversity of Iberian, Tithonian-Berriasian sauropod tracks and sedimentary environments.