Vol 61, Núm. 2, 2006, P. 215-224

On the occurrence of Gillicus arcuatus (Cope, 1875) (Pisces, Ichthyodectiformest†) in Mexico

Acerca de la presencia de Gillicus arcuatus (Cope, 1875) (Pisces, Ichthyodectiformes†) en México

Jesús Alvarado–Ortega1,* and Héctor Porras– Múzquiz2

1 Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México. Ciudad Universitaria, Coyoacán, D.F., 04510, México. *Email: This email address is being protected from spambots. You need JavaScript enabled to view it. .

2 Museo Histórico de Múzquiz, Ayuntamiento de Múzquiz. Hidalgo Norte 205, Zona Centro, Múzquiz, Coahuila, C.P. 26340, México.



This work provides the description of the first specimen of the species Gillicus arcuatus (Cope, 1875) collected in Mexico. This ichthyodectiform fossil was collected in a marl flagstone quarry on Los Pilotes Ranch, Muzquiz County, Coahuila. The rocks of the quarry are of Turonian age, and constitute part of the Eagle Ford Formation. This Gillicus arcuatus specimen fits within the known temporal distribution of Gillicus, but extends the geographical distribution of this species to include Northern Mexico, where once the North American Western Interior Sea and the Western Tethys Sea converged. Los Pilotes Ranch is the southernmost fossil locality so far known where Gillicus has been found.

Keywords: Gillicus, Ichthyodectiformes, Turonian, Eagle Ford Formation, Coahuila.