HI! I found this before ten years. Is it possible to identify if it is an egg?
Hmmm, intriguing. As we noted in response to an earlier question about an egg-like specimen, because eggs—even giant dinosaur eggs—are fragile, it’s quite rare to find fossils of intact eggs. Usually paleontologists find partial specimens of fossilized broken eggshells (sometimes accompanied by embryo parts).
This specimen of yours looks like maybe it could be a fossil egg; however, given the rarity of whole fossil eggs and the multitude of ways geologic forces create beautifully rounded forms, we can't assume that every well-rounded rock is an egg.
Paleontologists can infer a lot about specimens from the context in which they are found. Where did this specimen come from? If it came from a site where confirmed fossil eggshells or related fossils have been found, that would increase the likelihood that it's an egg. If it comes from a rock layer representing a time and place where we lack evidence even for species that would have create an egg like this, we have to acknowledge that and suppose that until better evidence supports it, it's probably a really nicely rounded rock.
Please do let us know if you have more details about where it came from! Size is also another good piece of information to have about specimens, although rounded rocks come in many sizes.
Santa Barbara City College Earth and Planetary Sciences Instructor (and SBMNH Teen Programs Manager) Jenna Rolle, M.S.