I think it is an auratum. I've had slightly larger slings of both as well as smithi and emilia. Of course what was sold to me as an emilia became a smithi and what was sold as a boehmei became an emilia. In each case I thought they were identifying them wrong. Carapaces often don't darken till later Iv'e noticed - my vagans took forever to go from all reddish through several molts to boom all black after its last molt.