Image Caption: University of Florida vertebrate paleontologist Jonathan Bloch shows the preserved skull of the 54-million-year-old primitive primate, Ignacius graybullianus, and the virtual mold of the brain made from the skull in this June 5, 2009, photo at Florida Museum of Natural History at the University of Florida. The mold, known as an endocast, was made using an ultra-high resolution X-ray CT scanner that took more than 1,200 cross-sectional images of the skull. (Eric Zamora/University of Florida)
A new study indicates that one of the earliest primates lived in trees and relied on smell more than vision.
Researchers reported in Tuesday's online edition of Proceedings of the National Academy of Sciences that a tiny cousin of the earliest ancestors of humans lived 54 million years ago in what is now known as Wyoming.
Mary T. Silcox, the team lead, and other researchers used a CT-scan to study the 1.5 inch skull of a primate known as Ignacius graybullianus.
The animal’s brain structure was modeled with the results, showing large olfactory lobes but less development in visual areas. This is a possible indication of a nocturnal animal that relies on insects for food.
Many of the ancestral primate brain models are based on tree shrews, which are related to humans. However, "it turns out three shrew brains are not a good model," said Silcox, an anthropologist at the University of Winnipeg in Canada.
According to co-author Jonathan Bloch of the University of Florida, Ignacius graybullianus represents a side branch of the primate tree of life. He said "you can think of it as a cousin of the main line lineage that would have given rise ultimately to us."
This animal was part of a group of primates known as Plesiadapiforms, which evolved during the extinction of the dinosaurs and the first traceable ancestors of modern primates.
The U.S. National Academy of Science and the Natural Sciences and Engineering Research Council of Canada supported the research."
No comments:
Post a Comment