Javier Cardenal

Photogrammetric techniques and 3D modelling are useful tools for obtaining morphological data, such as size, volume, and surface area, in paleontological studies, and its use is becoming increasingly simple, even with common devices such as mobile phones and tablets. This work takes as an example the skull of some of the largest theropods, Allosaurus fragilis (Carnosauria, Allosauroidea), Giganotosaurus carolinii (Carnosauria, Allosauroidea) and Tyrannosaurus rex (Coelurosauria, Tyrannosauroidea), for the elaboration of 3D models with the use of different photogrammetric and laser techniques. The study confirms that Tyrannosaurus head was shorter than that of Giganotosaurus but more robust with skull length/skull width ratio for T. rex (2.42) lower than for Giganotosaurus (2.98). The skull volume/lower jaw volume is higher in Giganotosaurus (3.68) than in Tyrannosaurus (3.31) also pointing to more robust head for T. rex. In addition, the mandible of Tyrannosaurus is deeper than that of other large theropods and robust thick pachydont dentition was probably adapted to develop high bite force. These features allowed T. rex to keep large prey and bite across meat and bone equally. Giganotosaurus is hypothesized to have had powerful slicing bites, based on its ziphodont dentition, and the capacity to manipulate relatively smaller preys compared with Tyrannosaurus, as inferred from its flattened lower jaw. Allosaurus, also from clade Allosauroidea like Giganotosaurus, had a narrow skull (skull length/skull width 3.24) equipped with straight pachydont teeth. Although the Allosaurus’ mandible was adapted to slice, capture and manipulate small preys, the skull volume/lower jaw volume ratio (3.53), lower than in Giganotosaurus, confirm that probably was also prepared to support high torsional stress when attacking larger preys.

Small trace fossils are recorded in the top and the bottom of a thin sandstone bed located in the upper part of the K1 unit (lower Carnian, Upper Triassic), in the Tabular Cover. In the top surface, two trace fossils have been identified: a tridactyl digitigrade elongated scratch mark with preserved triangular claws (20 mm long and 19 mm wide), with two lateral elongated (30 mm) and curved marks are located back to the margins of the tridactyl foot­print, and a longitudinal furrow (185 mm long and 3 mm wide). In the bottom surface there are two autopodium impressions preserved as convex hyporeliefs, counter moulds (45 mm long, 26 mm wide, and 18 mm long, 14 mm wide). They are tridactyl, elongated scratch marks, located very close and forming an angle of 48º. Trace fossils are interpreted as produced on the bottom by small tetrapods when floating in a low energy shallow environment. In the top surface correspond to the right hindlimb and the tail. In the bottom surface the scratch marks are more elongated and may be related to pes and manus. The potential authors are uncertain. This is a new example of swimming trace fossil for the Carnian deposits of the southern and eastern Iberia.

The study of the lower Berriasian (Lower Cretaceous) of the Sierra del Pozo (Internal Prebetic, Betic Cordillera) has made possible the discovery of three dinosaur tracks that correspond to the digitigrade footprints (28.7 to 26.1 cm long and 19.9 to 21.4 cm wide) of mesaxonic tridactyls. The tracks are located at the top of two shallowing-upwards sequences with desiccation-related mud cracks that correspond to supratidal facies. The trackmakers were medium-sized theropods, on the basis of the prints record, the claws, the elongated digits and the low interdigital angles. This is the only record at the South-Iberian Palaeomargin of theropod tracks, which are relatively scarce, compared to the Lower Cretaceous of other Iberian Palaeomargins.

Extensive canyons, excavated into the margins of the Levant Basin during the Oligocene–Miocene, are interesting case-studies for canyon fills in carbonate settings. The carbonate Pattish Formation, developed along the margins of the pre-evaporitic Messinian Beer Sheva Canyon in Israel, was investigated using both onshore seismic imaging and field data. The canyon has three main seismic facies of fill (1) Subparallel reflections mimicking the canyon´s morphology; (2) chaotic reflections overlying the subparallel ones, and (3) sigmoidal reflections, locally with sharp edges at the canyon margins. The first seismic facies corresponds to the pelagic marls of the Bet Eshel Formation. The other two seismic facies are, respectively, equivalent to bioclastic calcarenite clinobeds with slumps and channels, and to coral–stromatolite reefs and reef slopes of the Pattish Formation observed at outcrop. There were three phases of canyon development: (1) slope incision and headward erosion due to tectonic uplift and eustatic sea-level fall during the Early Oligocene, and large slope failure during the latest Middle Miocene; (2) platform incision and connection with a fluvial system in the Late Miocene related to falling sea level and tectonic uplift; and (3) canyon filling first by pelagic marls at the centre of the canyon, followed by calcarenite clinobeds at the canyon flanks formed by gravity flows. Finally, carbonate production at the margins of the canyon resulted in reefs and associated slopes prograding towards the canyon axis. The late canyon filling phase ended with the deposition of evaporites during the Messinian Salinity Crisis.

The aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families. The analysed polyvinyl chloride (PVC) models belong to the genera Coelophysis, Dilophosaurus, Ceratosaurus, Allosaurus, Baryonyx, Carnotaurus, Giganotosaurus, and Tyrannosaurus. The scanned 3D models were scaled considering different body-size estimations of the literature. The 3D analysis of these genera provides information on the skull length and body length that allows for recognition of major evolutionary trends. The skull length/body length in the studied genera increases according with the size of the body from the smallest Coelophysis with a ratio of 0.093 to ratios of 0.119–0.120 for Tyrannosaurus and Giganotosaurus, the largest study theropods. The study of photogrammetric 3D models also provides morphometric information that cannot be obtained from the study of bones alone, but knowing that all reconstructions begin from the fossil bones, such as the surface/volume ratio (S/V). For the studied theropod genera surface/volume ratio ranges from 35.21 for Coelophysis to 5.55 for Tyrannosaurus. This parameter, closely related to the heat dissipation, help in the characterization of the metabolism of extinct taxa. Accordingly, slender primitive forms of the Early Jurassic (i.e. Coelophysis and Dilophosaurus) had relatively smaller skulls and higher mass-specific metabolic rates than the robust large theropods of the Cretaceous (i.e. Giganotosaurus and Tyrannosaurus). This work presents a technique that, when applied to proper dinosaur models, provides extent and accurate data that may help in diverse study areas within the dinosaur palaeontology and palaeobiology.

This paper deals with the use of aerial photogrammetry and LiDAR techniques to analyze landslide activity over a long time span—just over 32 years. The data correspond to several aerial surveys (1984, 1996, 2001, 2005, 2009, 2010, 2011, 2013 and 2016) covering an area of about 50 km² along highway A-44, near Jaén (Southern Spain). An ad hoc combined photogrammetric and LiDAR aerial survey of 2010 was established as the reference flight. This flight was processed by means of direct orientation methods and iterative adjustments between both data sets. Meanwhile, historical flights available in public geographical data servers were oriented by transferring ground control points from the reference flight. Then, digital surface models (DSMs) and orthophotographs were generated, as well as the corresponding differential models (DoDs), which, after the application of filters and taking into account the estimated uncertainty of ± 1 m, allowed us to identify true changes on the ground surface. This analysis, complemented by photointerpretation, led us to obtain a landslide multitemporal inventory in the study area that was analyzed in order to characterize the landslide type, morphology and activity. Three basic typologies were identified: rock falls–collapses, slides and flows. These types present different morphometric properties (area, perimeter and height interval) and are associated with different conditions (height, slope, orientation and lithology). Moreover, a set of monitoring areas, common for the different flights, was also used to analyze the activity throughout the study period. Thus, some more active periods were identified (2009–2010, 2010–2011, 2011–2013 and 1996–2001) among other less active ones (1984–1996, 2001–2005, 2005–2009 and 2013–2016), which are related to rainy events and dry years, respectively.

Gully erosion is one of the main processes of soil degradation, reaching 50%–90% of total erosion in basins. As erosion processes are related to rainfall regime, the depletion and deposition rates can be increasing in a climate change scenario. This paper deals with the quantification of erosion processes in an active gully affecting olive groves of the province of Jaén (southern Spain), using geomatics techniques (photogrammetry and LiDAR). Eight historical aerial flights from 1980 to 2016, a LiDAR dataset (2014) and 2 recent UAS surveys (2019–2020) were used and processed in a common reference system with the support of field GNSS ground control points. Then, DSMs and orthophotographs were obtained and DSMs of differences (DoDs) calculated, from which we can identify gullies, calculate the depletion and deposition areas, and estimate height differences and volumes involved. These analyses result in an average depletion of about −1.6 m (incision) and a waste volume up to 30000 m3 (soil losses), which lead to a rates of −0.05 m/year and −44 t/ha*year, respectively. These rates are very different along the considered periods, reaching the maximum values (near −300–450 t/ha*year) in 2009–2011 and 2011–2013, coinciding with the periods of higher rainfall in the last fifty years, that probably have underwent an increase of 10–30% in the last decades. Thus, the evolution of the gully area for 40 years has been analysed in relation to the rainfall regime that has been established from the daily rainfall data.

An approach based on images captured by means of an Unmanned Aerial System (UAS) and Structure from Motion – Multi Video Stereo (SfM-MVS) photogrammetry is presented for the study of the gully erosion in a catchment area of about 16 ha. The study area is located in the province of Jaén (SW Spain) where the main land use is the olive groves. Three UAS flights have been made in April 2019, May 2019 and February 2020 with an average GSD of 2–3 cm. The image processing has been carried out using some field surveyed GNSS ground control points and the RTK positioning of the UAV with errors lower than 0.03 m and 0.04 m in XY and Z, respectively. Then DSMs and orthophotographs were obtained with a resolution of 0.10 m and 0.05 m, respectively, and DSM of differences (DoDs) were calculated, with an uncertainty of about ±0.15 m. Finally, the DoDs were analysed in the GIS, in order to calculate the height differences and volumes between the three flights. The analysis has showed the areas affected by the gully erosion processes that correspond mainly to ground descents due to significant channel erosion and mass movements at the steep sidewalls. Considering the balance between depletion and deposition processes, the average height differences is about −0.03 m and the volume is about −42 m³, that is the depletion predominates. The main changes have been detected in the second period (May 2019–February 2020), while in the first one (April 2019–May 2019) they are practically insignificant and limited to small areas.