Supporting agencies: This study was supported by the Russian Foundation for Basic Research (Project No. 18-09-40031). The author thanks A.I. Korolev, A.F. Kochkina, and D.A. Stashenkov for providing the photo of the staff from the Ekaterinovsky Mys burial ground, and for permission to use it in this publication. I am also grateful to A.A. Vybornov for his consultations during the preparation of this article.