According to two studies published this week in the journal Nature, the original dinosaurs may have produced soft-shell eggs,media CNET reported. The first study found that despite speculation that dinosaurs would lay hard-shell eggs, there was fossil evidence that certain types of dinosaurs — the protosmeus dragons and the rat dragons — produced Bioware shell eggs. These creatures bury these eggs in wet soil, just like some reptiles today.
The second study examined a softshell egg fossil found in Antarctica, which researchers believe dates back about 66 million years. It was the first time a dinosaur egg had been found in Antarctica — when it was closer to the equator than it is now and not as cold as it is.
The scientists in charge of the discovery believe the egg may have been made by dinosaurs because of its estimated weight and its proximity to other found egg fossils belonging to non-bird dinosaurs.
Together, these studies re-evaluate the theory that all dinosaurs would lay calcified hard-shell eggs — and speculate that dinosaurs may be more like reptiles. There is no doubt that over time, eggshells have evolved more often than soft shells. But because there are so few soft shell eggs on the fossil record, it is difficult to determine a reliable evolutionary timeline.