Publications by authors named "Jesus Alvarado-Ortega"

During the excavation of Mayan tombs, little did the archaeologists know that the fossils they discovered in the tomb stones would fundamentally alter our understanding of the earliest origins of coral reef fishes. Located just 500 kilometers from the point where an asteroid impact reconfigured the world's biological systems 66 million years ago, we find the earliest origins of three typical reef fish groups. Their presence in Mexico just 3 million years after this impact finally reconciles the conflict between the fossil and phylogenetic evidence for the earliest origins of reef fishes.

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Lepisosteoids are known for their evolutionary conservatism, and their body plan can be traced at least as far back as the Early Cretaceous, by which point two families had diverged: Lepisosteidae, known since the Late Cretaceous and including all living species and various fossils from all continents, except Antarctica and Australia, and Obaichthyidae, restricted to the Cretaceous of northeastern Brazil and Morocco. Until now, the oldest known lepisosteoids were the obaichthyids, which show general neopterygian features lost or transformed in lepisosteids. Here we describe the earliest known lepisosteoid (Nhanulepisosteus mexicanus gen.

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†Sorbinicharax verraesi is a marine teleostean fish from the Upper Cretaceous of Nardò (Italy). It was first attributed to the otophysan order Characiformes, which represents potential evidence for the controversial marine origin of the clade. Through a review of all the available material, we demonstrate that this species is not an otophysan since it lacks key structures that would allow for its inclusion in this group.

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Two species of fossil polydesmidan millipedes (Diplopoda: Polydesmida) embedded in amber are described from Miocene strata near Simojovel, in the Chiapas Highlands, Mexico. Maatidesmus paachtun gen. et sp.

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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.

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