cichlids postdate

Scientists have long theorized that cichlids evolved on the ancient continent of Gondwana. Once the continent began to drift apart, it carried cichlids with it to the regions of the world they are found today. Today cichlids are found in South America, Africa, Madagascar, and India. All areas that were once part of Gondwana. However, researchers from Oxford University are claiming that fossil and DNA evidence suggests that cichlids postdate the breakup of Gondwana. They believe that cichlids didn't make their appearance until about 65 to 57 million years ago. Granted that a lack of fossil records does not indicate that cichlids didn't exist prior to 65 million years ago, but that does leave an 70 million year gap between the earliest known cichlid fossil and the breakup of Gondwana.

These new claims certainly bring up some interesting questions. If cichlids postdate the breakup of Gondwana, how are they found on so many different continents? Did they at one time have a tolerance to salt water? Was there perhaps an island chain linking the continents as they drifted apart which enable the fish migrate between the continents? Were there areas of freshwater within the ancient oceans? For more information on this research, see the study on the Royal Society Publishing website.