Out of Africa

Revolutionary studies using molecular data to understand the phylogenetic relationships between living species and populations strengthen ideas about fossil relationships. The idea that Elephants, Hyraxes, and Elephant Shrews (the "Afrotheria") share a common ancestor came about by these revolutionary studies (Murphy et al 2001). Since then paleontologists have been trying to test this idea by finding intermediate species in the fossil record that show similarities. One group that may hold the answer is the louisinine mammals. These mammals are known primarily from the Paleogene of Europe and have previously been grouped with the North American hyopsodonts, such as Hyopsodus. New fossils of the ankle show characteristics with elephant shrews and hyraxes. They now should be regarded as afrotherian immigrants from Africa. The question still remains whether North American hyopsodonts are all one group, or whether some belong to the Afrotheria as well.

Tabuce, R. Antunes, M.T., Smith, R. and Smith, T., 2006. Dental and tarsal morphology of the European Paleocene/Eocene "condylarth" mammal Microhyus. Acta Palaeontologica Polonica 51 (1), p. 37-52.

See also: Murphy, W.J., Eizirik, E., O Brien, S.J., Madsen, O., Scally, M., Douady,
C.J., Teeling, E., Ryder, O.A., Stanhope, M.J., and de Jong, W.W. 2001. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science 294: 2348–2350.