His research reveals that in the case of marsupials, carnivorans and strepsirrhine
primates that eat harder, tougher and bigger foods have a lesser degree of fusion.
After evaluating 360 morphological features, Seiffert decided that, although the adapiforms shared certain traits with anthropoids--the loss of a third upper and lower premolar, for example--those characteristics had arisen more than once among primates and were "most parsimoniously interpreted as evolutionary convergences" Ida was not a haplorhine anthropoid, in other words, but rather a strepsirrhine
(a group including lemurs and lorises) that "left no known descendants.
Primate jumping genes elucidate strepsirrhine
Only further fossil finds on both continents will unravel the evolutionary roots of so-called strepsirrhine primates, which consist of lemurs and their close relatives the lorises, the scientists conclude in the Oct.
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.
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.
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.
Of particular interest, the researchers say, are teeth at the front of a Karanisia lower-jaw fragment that form a toothcomb like that of today's strepsirrhines.
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.