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Imágen SPOT del Volcán de Colima en donde se observa la red de drenajes que concentran los escurrimentos pluviales hacia la zona metropolitana de Colima-Villa de Álvarez, Estado de Colima, México (Fuente imagen ERMEX-SPOT IMAGE S.A.); véase el artículo relacionado de Pérez-González et al. en este número.

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Thin section under petrographic microscope of fossil remains of the rebbachisaurid sauropod Katepensaurus goicoecheai of Bajo Barreal Formation (Upper Cretaceous, Argentina). Part of a permineralized vascular canal is observed, including a first layer of hematite, a second layer of silica as chalcedony and quartz, and a third layer in the center that fills completely the canal with zeolites (crossed nicols). See Casal et al. (2017) in this issue.

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Labial view of Neochoerus occidentalis from late Blancan of Tecolotlán basin, Jalisco, Mexico. The masseteric ridge ends in p4, the entire simphysis and the complete incisor ends in the second prism of the first molar in the lingual side; The genus Neochoerus is among the first neotropical migrants in the central region of Mexico; see article by Carranza-Castañeda in this issue. Photo by: J. Jesús Silva Corona.

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In northern Sierra Plomosa, south of Placer de Guadalupe –a classical locality of paleozoic exposures 100 km northeast of Chihuahua City– a siliciclastic Lower to Middle Jurassic marine-marginal succession, rest unconformable on carboniferous limestones of the Pastor Formation. The siliciclastic unit, considered previously as Early Permian in age was recently dated as Early to Middle Jurassic according to U-Pb (zr) ages from ignimbrite and rhyolitic flows that occur concordant in the succession. Photo by: José Rafael Barboza Gudiño, 2012.

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Rincón de Parangueo, located in the Santiago Valley, in the State of Guanajuato is a maar that has dried due to the large groundwater ex­traction required for irrigating crops in the region. The active deformation of the maar’s bottom (which includes both uplift and subsidence) has created a series of structures on its surface. Photo: Jaime J. Carrera-Hernández.

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Chevron folds in quartz schists of the Neoproterzoic Difunta Correa Metasedimentary Sequence, Sierra de Pie de Palo, Argentina. Photo by : Agustín Kriscautzky (geology student, Universidad Nacional de Córdoba, Argentina).

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View to the NW of Sierra de la Giganta, from the road to Agua Verde, Baja California Sur. The sierra is made up of rocks of the early to late Miocene Comondú Group, mainly massive andesitic breccias, conglomerate and sandstone, with subordinate volumes of domes, lava flows and dikes. Photo: Teresa Orozco.

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Simplectic texture (diablastic) – intergrowth of scapolite and diopside in the contact with a quartz-feldspathic gneiss in the pegmatite La Planchita,Oaxaca, Mexico. The photograph was taken with an optical microscope with crossed nicols. Photo: Valentina Shchepetilnikova and Jesús Solé.

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Spontaneous fission tracks in a detrital apatite crystal from the Todos Santos Formation sandstone, the State of Chiapas, Mexico. These linear damages, which show random directions, were formed in apatite by the spontaneous fission of trace amounts of natural uranium. Polished apatite was etched in 5.5N HNO3 a at 21 °C for 20 s to reveal 238U spontaneous fission tracks. Photomicrograph by Fanis Abdullin and Jesús Solé.

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Emergence breccia in platform limestones of the Zicapa Formation, from outcrops south of Tlapa de Comonfort (Guerrero state). The breccia is composed of angular clasts of a grainstone up to 50 cm in diameter, occasionally containing abundant rudist and bivalve fragments replaced by silica, in a quartz-rich sandstone matrixwith pigmentary hematite. See article in this number by Sierra Rojas and Molina-Garza. Photograph: Roberto Stanley Molina-Garza.

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Oblique aerial photograph showing the geomorphic expression of the active Pastores Fault (Acambay graben, Mexico). The escarpment, which is the consequence of cumulative displacements on the fault, forms a topographic limit that appears partially covered by clouds. See related paper by Langridge et al. in this issue. Photo courtesy of F. Enrique Camacho.

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Clusters of cubic halite crystals formed under a layer of water from a brine in Salina de Ambargasta (NW of Cordoba and SW of Santiago del Estero, Argentina). The crystals were precipitated in the stage of evaporitic concentration within an annual cycle (at the end of the austral summer). Zanor et al., this issue.

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Schematic representation of a sinuous-crested complex draas identified in the Allen Formation, Malargüe Group, Neuquina - Río Negro basin, Argentina (Armas and Sánchez, this issue). Truncation and reactivations surfaces are evidence of variations in the directions of paleowinds or in the supply during the dune advance. Person silhouette for scale at the right side.

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Basaltic lava flow with vertical columnar jointing that crops out in the Aguacatitla canyon, Hidalgo State, Mexico, at the northeastern Trans-Mexican Volcanic Belt. These lavas were erupted from fissures and are part of the Pliocene-Quaternary Atotonilco Formation. Person for scale at the bottom right corner. Photo: Teresa Orozco.

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Female of Divocina noci sp.nov. from the Middle Jurassic of Daohugou in China, representing the extinct group of predatory cockroaches. This smallest representative of the family (wingspan 24 mm) is the first one which provided parallel comparison of variability and symmetry in any fossil insect, and not at last, helps to disentangle the nocturnal cohort of insects, apparently present, but unstudied in the Mesozoic ecosystems. Photo: J.H. Liang, P. Vršanský, and D. Ren

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Perspective scene from susceptibility landslides model of Puerto Vallarta, Jalisco, Mexico (Muñiz-Jauregui and Hernández-Madrigal, 2012, pages 103-114 of this issue). Model section view that looks at the Northeast and shows the central part of the city that is cut by the course of the Cuale River to its outlet in the Pacific Ocean. The image distinguishes different degrees of susceptibility (color ramp of red brown to green) on slopes on which the urban structure is located (block’s boundaries) with greater representation of this touristic port.

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View from south to north of the Sierra Pinta Permian granitoid pluton, NW Sonora, Mexico. These calc-alkaline granitoid rocks of Permian age are associated with the early stages of subduction and the establishment of the Cordilleran continental arc of southwestern North America. Note that the foothills are unconformably covered by sandy deposits, which have been transported mainly by wind action, forming and shaping sand dunes. Photo: Harim E. Arvizu.

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Limacina karasawai, a new species of pteropod described in the paper “Oligocene pteropods (Gastropoda: Thecosomata) from the Kishima Formation, Saga Prefecture, southwest Japan” by Yusuke Ando within this issue. It is one of the fi rst described species from the Japanese Oligocene.

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Staurolite mica schist of the Middle to Late Ordovician Río Fuerte Formation, which outcrops in northern Sinaloa, Mexico.Staurolite porphyroblasts contain aligned inclusions of quartz and opaque minerals defining an internal foliation, which is oblique or orthogonal to the foliation outside the poikiloblasts. Also, an hourglass twin can be seen in one of the staurolite crystals. Further details can be found in the paper by Vega-Granillo et al. published in this issue.