title: Cipactlichthys scutatus, gen. nov., sp. nov. a new Halecomorph (Neopterygii, Holostei) from the Lower Cretaceous Tlayua Formation of Mexico.
abstract: Based on specimens from the Lower Cretaceous Tlayua Formation of Mexico, we describe a new genus and species of Halecomorphi, Cipactlichthysscutatus gen. et sp. nov, which exhibits several diagnostic characters such as the dermal bones and the scales with ganoin and highly ornamented by numerous tubercles and ridges; parietal slightly longer than wide with approximately the same length as the frontal; jaws extending far, below the posterior orbital margin, reaching the posterior third of the postorbital plate; maxilla with a convexly rounded posterior margin; pectoral fin margins slightly convex; first ray of pectoral fin very long, reaching the posterior edge of the pelvic fin; about 37 preural vertebrae and 7 Ural centra; a series of hypertrophied scales just posterior to the cleithrum; arrangement of flank scales with two rows of deep scales; a series of dorsal and ventral scutes forming the dorsal and ventral midline, between the dorsal and anal fins and the caudal fin. A phylogenetic analysis including two outgroups and eleven neopterygians confirmed the monophyly of the Holostei as well as the monophyly of the Halecomorphi, although this last clade is weakly supported. Cipactlichthysscutatus was hypothesised as the sister-group of the (Ionoscopiformes + Amiiformes).
authors.affiliation: Departamento de Zoologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Paulo M
authors.initials: PM
authors.lastname: Brito
authors.forename: Jesus
authors.initials: J
authors.lastname: Alvarado-Ortega
mesh_terms: D000818:Animals; D005399:Fishes / Q000145:classification*; D055593:Geological Phenomena; D008800:Mexico; D010163:Paleontology; D010802:Phylogeny
references.citation: Proc Biol Sci. 2007 Feb 22;274(1609):489-98
references.pmid: 17476768
references.citation: PLoS One. 2012;7(7):e39370
references.pmid: 22808031
references.citation: Philos Trans R Soc Lond B Biol Sci. 1975 Jan 2;269(899):275-579
references.pmid: 234190