Researchers have found the world's oldest crocodilian eggs that were laid 152 million years ago.The eggs, discovered in cliffs in Portugal, were laid by close relatives of "true" crocodiles, a group called crocodylomorphs, which according to palaeontologists, had been two metres long."The fact that they are from the Late Jurassic period makes these eggs the oldest crocodilian eggs known so far," Joao Russo from the Nova University of Lisbon in Portugal was quoted as saying to the BBC."The fossil record tells us that crocodiles and their relatives (forming the larger group of crocodylomorphs) were much more diverse in the past, with different feeding habits, ecological niche distribution or morphology," he added.The eggs were found in several clutches and appear to be of two different types, the researchers said in the paper published in the journal, Plos One."This new discovery from Portugal extends the knowledge of this type of egg by approximately 40 million years," Russo added.