Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs

Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.Fil: Hendrickx, Christophe Marie Fabian. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Bell, Phil R.. University Of New England; AustraliaFil: Pittman, Michael. Colegio Universitario de Londres; Reino UnidoFil: Milner, Andrew R. C.. No especifíca;Fil: Cuesta Fidalgo, Elena. Bayerische Staatssammlung für Paläontologie und Geologie; AlemaniaFil: O'Connor, Jingmai. No especifíca;Fil: Loewen, Mark. No especifíca;Fil: Currie, Philip J.. University of Alberta; CanadáFil: Mateus, Octávio. Universidade Nova de Lisboa; PortugalFil: Kaye, Thomas G.. Foundation For Scientific Advancement; Estados UnidosFil: Delcourt, Rafael. Universidade Estadual de Campinas; Brasi

Concavenator corcovatus: (Theropoda, Dinosauria) from Las Hoyas fossil site (Early Cretaceous, Cuenca, Spain): taphonomic, phylogenetic and morphofunctional analyses

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 10-02-2017Esta tesis tiene embargado el acceso al texto completo hasta el 10-08-2018Theropods are a widely taxonomically, paleobiogeographically and morphologically diverse group that include the extant birds. The non-avian theropod record in the Iberian Peninsula is represented by Portuguese taxa and some fragmentary remains in Spain. However, the two taxa founded in Las Hoyas fossil site represent the most complete theropod inside the Iberian Peninsula and Europe. Las Hoyas fossil site is a Konservat-Lagerstätte that is reconstructed as a subtropical wetland with a strong biannual seasonality. The fossils from Las Hoyas are characterized by their completeness, articulation and preservation of soft-tissues and colour patterns. Two non-avian theropods founded in this site, Pelecanimimus polyodon and Concavenator corcovatus, show these preservation features, which allow to perform an exhaustive paleoecological analysis. Concavenator is the most complete dinosaur founded in the locality and, also, it represents the largest taxon preserved. Although its taphonomic features are coherent with the preservation framework of the Las Hoyas wetland, its terrestrial condition and size are infrequent in the fossil site, and thus, its presence raises issues about its processes of preservation. One of the aims of the current PhD thesis is reconstructing the taphonomic history that affect to Concavenator carcass. The methodology consists of several methods proposed in previous studies about the archosaurian preservation in Las Hoyas fossil site. The taphonomic analysis shows that Concavenator carcass suffered several processes as: early decay, dragging and slightly transport, rehydration and, finally, entombing into the microbial mats developed in Las Hoyas pools. These processes were consistent with the dynamic of the climate in Las Hoyas during the Lower Cretaceous. Therefore, the results not only clarify the processes produced on Concavenator, but it also sheds light on the understanding of mechanism acting in Konservat-Lagerstätten throughout the world. The exquisite preservation of Concavenator allows to discern several anatomical features in the skeleton and soft-tissues impressions. In this PhD thesis, these soft-tissues impressions have been analysed and the results have determined a new conception of various anatomical structures, such as the avian podotheca. This podotheca is consisting of three types of scales, similar to those observed in the extant birds, plantar pads with an arthral disposition and corneous sheet around the ungual phalanges. Moreover, the completeness of the skeleton has allowed to carry out an exhaustive osteological description and phylogenetic analysis. Concavenator is a basal member of Carcharodontosauridae and has several synapomorphies within the clade as the lacrimal-postorbital contact or a peg-and-socket articulation between the ilium and ischium, among others. This phylogenetic position of Concavenator has the best obtained support value of branches until now. Historically, carcharodontosaurids have been considered exclusively from Gondwana, however, recent discoveries show several taxa throughout Laurasia. The European position of Concavenator during the Early Cretaceous is key to understand the faunal interchanges between both continents. Finally, two unusual and striking features are present in Concavenator, a series of bumps on the ulnar shaft and hypertrophied neurapophyses of the posterior dorsal and anterior caudal vertebrae. Both features have been analysed in the current thesis. The muscle reconstruction of the forearm suggests that the bumps are not related to myological origin. Regarding the axial skeleton, the unusual features of its vertebrae bestow stiffness during the locomotion and these features could be related to the presence of an axial structure in the pelvic area. These results propose new future research projects in order to determinate the functional morphology of both structure

Synthesis and evaluation of new Reissert analogs as HIV-1 reverse transcriptase inhibitors. 1. Quinoline and quinoxaline derivatives

The synthesis and preliminary evaluation of new quinoline and quinoxaline derivatives (obtained by applying the original Reissert method, conveniently modified) as HIV-1 Reverse Transcriptase (RT) inhibitors are presented in this paper; likewise, the first structure-activity relationships are also proposed. Propyl 2-cyano-1(2H)-quinolin-carboxylate 2e, isopropyl 2-cyano-1 (2H)-quinolincarboxylate 2f, butyl 2-cyano-1 (2H)-quinolincarboxylate 2g and isobutyl 2-cyano-1 (2H)-quinolincarboxylate 2h have been selected as lead compounds. These compounds are active against the HIV-1 RT mutant type P236L (2f, IC50 = 1.2 microM) and present activity as anti-infective agents in HLT41acZ-1IIIB cells, showing no cytotoxicity at the active concentrations