Amiidae

Abstract: To investigate the relationships among the three main groups of extant neopterygian fishes--Amiidae, Lepisosteidae, and Teleostei--we sequenced fragments of three mitochondrial genes from 12 different actinopterygian fishes and translated the nucleotide sequences into amino acid sequences. When all three regions are considered together, Amiidae clusters with Lepisosteidae in the most parsimonious cladograms, but other clades, such as Neopterygii and Teleostei, that are well supported by morphological evidence fail to emerge as monophyletic. When the cytochrome b sequences are analyzed together with previously published sequences for other taxa, the majority-rule consensus tree is consistent with the monophyly of Teleostei and Neopterygii and marginally supports the Amiidae + Lepisosteidae clade. In either analysis, when Neopterygii and Teleostei are constrained to monophyly, all the most-parsimonious cladograms support the Amiidae + Lepisosteidae topology. Where molecules and morphology disagree, provisional morphology-based constraints on the analysis of molecular data offer a practical means of integrating the two types of data.

Abstract: A new locality named El Pelillal (Cerro del Pueblo Formation, Late Cretaceous, Campanian) in the southeastern area of the State of Coahuila, Mexico yields an assemblage of vertebrates that is important for correlation due to its frequent occurrence in other localities along the Cerro del Pueblo Formation outcrops. It is located in the Municipio de Ramos Arizpe, Coahuila. Among the vertebrates found are: fishes (Lepisosteidae; Amiidae [cf. Melvius sp.]); turtles (Trionychidae, Chelydridae [cf. Protochelydra sp.], Kinosternoidea [cf. Hoplochelys sp.], an undetermined kinosternoid genus, and ?Pleurosternidae [Compsemys vieta]); Crocodilians Neosuchia (Goniopholididae); and Eusuchia and a pterosaur (Pterodactyloidea). Dinosaurs found include a hadrosaurine hadrosaur, a new Troodontidae, and other indeterminate theropods. The El Pelillal Locality is interpreted as a freshwater environment possibly influenced by tides. The fauna of the El Pelillal locality, Cerro del Pueblo Formation, resembles souther...