Archosaurs, in turn, are the lineage that encompasses two of the best-known groups of terrestrial vertebrates: crocodiles and dinosaurs, including birds. Silescelida acristata was a relatively small, slender animal that moved on all four limbs. One of the most significant characteristics of Silescelida acristata lies in its femur, the thigh bone. The ‘rediscovery’ of a forgotten fossilThe discovery of Silescelida acristata also has an unusual history. Discoveries such as Silescelida acristata show that even isolated parts of the skeleton can reveal fundamental information about evolution.