It weighed only about 370 grams and probably resembled a modern-day dwarf lemur, but this tiny fossil primate made quite a large splash when it was first discovered in the West Texas badlands in 2005. Not only was the animal a previously unknown species, but it served as further evidence of the exchange of fauna between North America and East Asia, which were connected when the primate was alive, 43 million years ago.
North American Primate Species
This new primate — dubbed Mescalerolemur horneri in honor of the Mescalero Apache tribe who once lived in the area and entomologist Norman Horner — was not the first fossil primate found in the Devil's Graveyard in West Texas, though so far it is the most ancient, being three to four million years older than a fossil primate discovered in 1973 known as Mahgarita stevensi.
Both animals belong to a group of extinct primates known as adapiforms, but interestingly, M. horneri and M. stevensi are more closely related to primates native to Africa and Eurasia than they are to other North American primate species. This strongly suggests that there was a great deal of interchange between the Asian and North American continents during the Eocene epoch.
Human Ancestor?
When M. horneri was first discovered, it was thought to be a smaller species of M. stevensi, but further research revealed its true lineage. The new primate is closely related to Darwinius maxillae, a fossil primate discovered in Germany and once touted as a human ancestor.
Study of the similarities between M. horneri and D. maxillae, however, reveal that both of these adapiform primates are likely more related to modern lemurs or bush babies than they are to humans. The lower jaw of M. horneri, for instance, is comprised of two separate bones like a modern lemur, rather than the fused lower jaw seen in humans and apes.
Climate Change and Extinction
It is likely that M. horneri represents the last of a group of primates native to the North American continent. The end of the Eocene was marked by a period of sustained cooling, and while the tropically adapted primates apparently lived for a time in the relatively warmer climes of what is now West Texas, eventually the colder climates caused their extinction.
Source:
- University of Texas at Austin. "Anthropologist discovers new fossil primate species in West Texas." ScienceDaily, 17 May 2011. Web. 31 May 2011.
Jenny Ashford - Jenny Ashford is a writer and graphic artist from central Florida. Her main area of interest in her Suite 101 articles is science, with a ...
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