"This is pretty compelling evidence for the earliest strepsirrhine in the fossil record," remarks D.
For instance, a thin, flattened fossil tooth with a scoop-shaped inner surface resembles the lower canine tooth of today's strepsirrhines, they say.
Says Gunnell, "This is a very important find that raises new questions about the origin of strepsirrhines."
Phylogenetic analyses suggest that anchomomyins might be related to either asiadapines or crown strepsirrhines.
A total of 25 primate genera, corresponding to 7 families (one of plesiadapiforms, 2 of strepsirrhines and 4 of haplorrhines), from up to 116 different localities, are reported (27 from the Eocene, 3 from the Oligocene, 32 from the Miocene, 4 from the Pliocene, 51 from the Pleistocene and one with an undetermined age).
These new finds double the age of the sparse fossil record for lorises and bushbabies, which with lemurs make up a primate group called the strepsirrhines. It originated in Africa at least 50 million years ago, the scientists conclude in the March 27 Nature.
Martin of the Field Museum in Chicago cites the genetic data in support of his view that strepsirrhines originated in southern Asia around 80 million years ago.
They also note that the article on Darwinius published last year in the journal PLoS ONE ignores two decades of published research showing that similar fossils are actually strepsirrhines
, the primate group that includes lemurs and lorises.
Divergence between strepsirrhines
(lemurs and lorises) and haplorhines (tarsiers and anthropoids) is correlated with intense volcanic activity on the Lebombo Monocline in Africa about 180 million years ago.