Abstract:
The presence of Pseudohaploceras liptoviense (ZEUSCHNER) associated to Palorbitolina lenticularis is (BLUMENBACH) permits to interpret an Early Aptian age for the middle part of the lower member of the Cumburindio Formation nearby Turitzio (Michoacan). It is proposed that Bose's species ''Desmoceras'' aguilerae, ''D.'' alzatei, ''D.'' burckhardti, ''D.'' durangense, ''D.'' tenuicostatum and ''D.'' wielandi are younger synonymous of Pseudohaploceras liptoviense (ZEUSCHNER). An alternative interpretation as Mexican colonizers very close to Pseudohaploceras liptoviense (ZEUSCHNER) cannot be conclusively disregarded.