The first Gondwanan borioteiioid lizard and the mid-Cretaceous dispersal event between North America and Africa

Reinhold Fritzgaertner y los reportes de fósiles de Honduras a finales del siglo XIX

Durante el siglo XIX el Gobierno de Honduras propició la llegada de académicos extranjeros, siendo el geólogo y paleontólogo alemán Reinhold Fritzgaertner uno de los casos más notorios por su influencia en el impulso de la actividad minera en Honduras, sin embargo, se ha descrito muy poco su rol en la historia de la paleontología de América Central. A través de una extensa revisión documental en bibliotecas virtuales de Europa y América, en el repositorio virtual Tzibalnaah-UNAH y en el Archivo Nacional de Honduras, se buscó determinar los vínculos académicos de Reinhold Fritzgaertner y su aporte en la investigación de la paleontología de Honduras en el siglo XIX. Fritzgaertner llega a Honduras después de completar sus estudios de doctorado bajo la asesoría del renombrado geólogo y paleontólogo alemán Friedrich August von Quenstedt y de fungir como asistente del renombrado geólogo y paleontólogo norteamericano James Hall, manteniendo vínculos con importantes instituciones académicas de la época. Su presencia en Honduras trascendió la minería y desarrolló un papel notorio en la historia de la ciencia de este país, en una época en que la evidencia paleontológica de Honduras adquirió importancia en el mundo académico. Fritzgaertner puede ser considerado el académico que tuvo el mayor conocimiento de la paleontología de Honduras en el siglo XIX, y mediante su participación en las diferentes exposiciones mundiales, los reportes en medios escritos de divulgación y sus vínculos académicos internacionales, propició el reporte de fósiles de Honduras a finales del siglo XIX. Palabras clave: Paleontología, América Central, Historia de Honduras, Exposiciones mundiales.

A new Early Cretaceous lizard in Myanmar amber with exceptionally preserved integument

We here report on a well-preserved juvenile lizard specimen in Albian amber (ca. 110 mya) from the Hkamti site (Myanmar). This new taxon is represented by an articulated skull and the anterior portion of the trunk, including the pectoral girdle and forelimbs. The scleral ossicles and eyelid are also visible, and the specimen exhibits pristine detail of the integument (of both head and body). In a combined molecular and morphological analysis, it was consistently recovered as a scincoid lizard (Scinciformata), as sister to Tepexisaurus + Xantusiidae. However, the phylogenetic position of the new taxon should be interpreted with caution as the holotype is an immature individual. We explored the possibility of miscoding ontogenetically variable characters by running alternative analyses in which these characters were scored as missing data for our taxon. With the exception of one tree, in which it was sister to Amphisbaenia, the specimen was recovered as a Pan-xantusiid. Moreover, we cannot rule out the possibility that it represents a separate lineage of uncertain phylogenetic position, as it is the case for many Jurassic and Cretaceous taxa. Nonetheless, this fossil offers a rare opportunity to glimpse the external appearance of one group of lizards during the Early Cretaceous.

Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco

The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the "Kem Kem beds", are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward large-bodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms. No comparable modern terrestrial ecosystem exists with similar bias toward large-bodied carnivores. The Kem Kem vertebrate assemblage, currently the best documented association just prior to the onset of the Cenomanian-Turonian marine transgression, captures the taxonomic diversity of a widespread northern African fauna better than any other contemporary assemblage from elsewhere in Africa.