GZG 769-3, GZG 773-20, GZG 773-34, and GZG 773-43 (paralectotypes), isolated costal, hyoplastron, and hypoplastra (Maack 1869, pls. 34.21, 35.35, 36.44; Portis 1878, pl. 15.3–5; Karl, Gröning and Brauckmann 2012, pls. 1.1, 2, 2.3, 4, 2.5, 6). Portis (1878) erected Tropidemys seebachi based on a series of five specimens, including an anterior part of carapace that was recently designated as the lectotype (Karl, Gröning and Brauckmann 2012). Among the four paralectotypes, three iso- lated plastral fragments are of questionable affinity, especially considering that they also serve as part of the type series of Style- mys lindenensis Maack, 1869 and Stylemys hannoverana Maack, 1869 (see below). Portis (1878) transferred these to Tropidemys seebachi based on a strong resemblance with plastral material from Solothurn referred to Tropidemys langii by Rütimeyer (1873a). However, this attribution of the Solothurn material was recently shown to be incorrect (Püntener et al. 2014), and there is therefore no solid evidence to support the assignment of the three aforementioned plastral elements to Tropidemys seebachi.

Tropidemys seebachi was named by Portis (1878). Its type specimen is GZG 769-1 (lectotype), a partial shell (articulated anterior part of a carapace, including four neurals and five incomplete costals), and it is a 3D body fossil. Its type locality is Tönjesbergs, near Hannover, which is in a Kimmeridgian marine horizon in Germany.