Heterogeneidad lateral en las muestras de roedores del tramo T1 del Mioceno Medio de Somosaguas (Pozuelo de Alarcón, Madrid)

摘要: Rodent associations are habitually used in palaeoenviromental inferences. Assuming lateral homogeneity fossil content within stratigraphic levels, sometimes these inferences performed using the relative abundances of species included such associations. Nevertheless, this has never been checked empirically proportions inside same fossiliferous level. Because that, work we compared two samples from T1 level Somosaguas site (middle Miocene), which were separated laterally by 30 m. Although both show identical faunal composition a qualitative viewpoint, analysis realized through Monte Carlo randomizations indicated existence significant differences different between samples. These results could be due to 1) sedimentary behaviour dental pieces size; 2) small size sediment combined with high density remains Somosaguas; 3) differential time averaging related presence successive alluvial fans, associated population changes environmental during Aragonian. Our need cautiousness when based on micromammalian species.