Basal Sauropodomorpha (Dinosauria, Saurichia

OTERO, ALEJANDRO; POL, DIEGO; APALDETTI, CECILIA

Buenos Aires

Jornada; XXX Jornadas Argentinas de Paleontología de Vertebrados; 2016

Museo Argentino de Ciencias Naturales

Basal sauropodomorphs include the non-sauropod portion of Sauropodomorpha, which lived in all continental landmasses between the Late Triassic and Early Jurassic. The early evolution of the group is well recorded in Carnian beds of Argentina and Brazil, achieving a rapid diversification during Norian and Rhaetian, adding records from South Africa, India and Europe. After the Triassic/Jurassic extinction, most lineages of Rhaetian sauropodomorphs continued into the Early Jurassic, extending to North America, China, and Antarctica. Carnian sauropodomorphs were not diverse, abundant or morphologically disparate. During the Norian they notably diversified both taxonomically and ecologically, became abundant and dominated terrestrial ecosystems. By the Early Jurassic, Sauropodomorpha achieved their broadest geographical distribution and morphological disparity, ranging from small-medium size and facultatively bipedal forms to giant quadrupedal sauropods. The diversity and disparity of Sauropodomorpha changed radically at the end of the Early Jurassic when all lineages became extinct, except for the gravisaurians, which subsequently gave rise to Eusauropoda becoming the dominant megaherbivores during the rest of the Mesozoic.