Vallecillo, Nuevo León: una nueva localidad fosilífera del Cretácico Tardío en el noreste de México

Abstract

In the vicinity of Vallecillo, N.L. Mexico, laminated marlstones of Turonian age contain well- preserved fishes, marine turtles, ammonites and inoceramids and indicate deposition under outer shelf environments. The absence of benthic faunal elements and bioturbation suggests stagnation and anaerobic sediment conditions. The selacean fauna consists of teeth of Ptychodus mortoni, body impressions of cf. Scyliorhinus and vertebra of an unidentified shark. Picnodontids are probably represented by two familes. Teleosteans are represented by Ichthyodectiformids (one family), Tselfatiforms (one family), Aulopiforms (one family, two genera) and Pachyrhyzodontids (one family).

The fauna present at Vallecillo is similar to tethyan associations from Libanon, Israel, Mrocco, and to assamblages of the Western Interior Seaway of the USA (e.g., Kansas). The geographic distribution of some tethyan fishes is extended into Mexico.