Researchers said they now have a better understanding of mammalian evolution. "With adaptations like webbed feet to fit its aquatic lifestyle and the poison spurs that decorate males, the platypus represents for many a patchwork of evolutionary development," Louisiana State University officials said Wednesday in a news release.

"Their genomic organization was strange and a little unexpected," LSU biologist Mark Batzer said in a statement. "It appeared much more bird- and reptile-like than mammalian, even though it is indeed classified as a mammal."

Batzer said the research provides insight into mammalian gene regulation and immune systems.