The earliest known Haplorrhini primate was recently described by Franzen et al. (2009) from the Messel shale in Germany from the Eocene (47 million years ago).
Franzen, J. L., Gingerich, P. D., Habersetzer, J., Hurum, J. H., von Koenigswald, W. and Smith, B. H. 2009. Complete primate skeleton from the Middle Eocene of Messel in Germany: Morphology and paleobiology. PLoS One. 4(5):e5723.