User blog comment:ASDFGirl/The Future of Fossils and Archeology: Revival/@comment-31.151.185.164-20180416134757/@comment-67.231.169.71-20180416191149

Likely fish or fish eggs. However it's confirmed in the fossil record to eat small crustaceans like shrimp. So perhaps mod integration with Pams Harvestcraft or they may add crustaceans for Pterodustro and other aqautic or semi-aqautic creatures.