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La Pastora tholos is the most complete and characteristic megalithic monument of the Valencina de la Concepción-Castilleja de Guzmán mega-site. This monument was built using three types of rock, each with different functions and coming from three different places: Paleozoic quartzarenite, granite, and Tertiary calcareous sandstone. A detailed petrological study of the rocks of the tholos and outcrops of similar rocks in the surroundings has been carried out, locating the possible source areas in areas at least 30 km to the N of the monument for the quartzarenite, 15 km for the granite, and 15 km to the S for the sandstone. Therefore, the community that built the monument has a high knowledge of the nature by, which allows them to locate these resources, and a sufficient social organization to exploit them and move them to the mega-site. In this sense, the layout of the outcrops suggests the possible use of boats or rafts to facilitate their displacement, or at least part of their movement. [ABSTRACT FROM AUTHOR]

Vertebrate macroevolution has been punctuated by fundamental habitat transitions from shallow marine origins to terrestrial, freshwater, and aerial environments. Invasion of the deep sea is a less well-known ecological shift because of low fossilization potential and continual loss of abyssal fossil record by ocean floor subduction. Therefore, there has been a lack of convincing evidence of bottom-living vertebrates from pre-Paleogene deep seas. Here, we describe trace fossils from abyssal plain turbidites of the Tethys Ocean, which, combined with nannofossil dating, indicate that fishes have occupied the deep seafloor since at least the Early Cretaceous (Hauterivian-Barremian). These structures are identical to those produced by modern demersal fishes that feed by either scratching the substrate or expose their prey by water flow generated by suction or jetting. The trace fossils suggest activity of at least three fish species exploiting a productive abyssal invertebrate sediment fauna. These observations are consistent with Early Cretaceous vertebrate transition to the deep sea triggered by the availability of new food sources. Our results anticipate the appearance of deep-seafloor fishes in the fossil record by over 80 My while reassessing the mode of vertebrate colonization of the deep sea. [ABSTRACT FROM AUTHOR]

The c. 100 myr extensive fossil record of bee brood nests and cells (calichnia) in siliciclastic sedimentary deposits, or palaeosols, is virtually devoid of the presence of their producers. The absence of a more specific assignment to a producer of the different ichnogenera of the ichnofamily Celliformidae precludes their use in phylogenetic and palaeobiogeographic studies. Omission surfaces developed in incipient carbonate palaeosols during the late Holocene (middle Neoglacial), c. 2975 yr cal BP, on the southwest coast of mainland Portugal show insect calichnia in dense ichnofabrics dominated by shallow discrete cells (Palmiraichnus castellanosi) and cells at the terminus of vertical shafts. At Carreira Brava, one of the studied sites, bees ready to abandon their cells were found in an exceptional state of preservation inside the sealed brood chambers. The chambers also preserve the inner cell hydrophobic polymerized membrane and remains of the monospecific Brassicaceae‐type pollen provision. Although the cause of mass mortality remains a mystery, oxygen depletion due to sudden flooding of the nesting substrate and consequent or overnight temperature drop, just before emergence, are plausible causes. The anaerobic conditions and later rapid carbonate diagenetic lithification are the likely causes of the preservation of the bees and the inner cell organic membrane. The favourable climate conditions for the development of successive, dense ichnofabrics from an omission suite dominated by bee brood cells may be the result of slightly colder and higher‐precipitation winters during the Neoglacial interval. [ABSTRACT FROM AUTHOR]

The ghost shrimp Turbiocheir minutospinata has so far been known only from its holotype from the Eocene/Oligocene rocks of Río Turbio, Patagonia in Argentina. Recently, the additional specimen has been found in the Eocene strata of the Boca Lebu Formation of the Arauco Basin, Chile. New material adds information on the morphology of chelipeds and allows evaluation of the degree of heterochely of the studied ghost shrimp. Moreover, comparison of Turbiocheir minutospinata with extant ghost shrimp taxa allows synonymisation of Turbiocheir with Anacalliax. With this act the fossil record of Anacalliax is extended into early Eocene. The occurrence of Anacalliax minutospinata comb. nov. is proposed to represent a reliable calibration point for Anacalliacidae, which was not available until now. [ABSTRACT FROM AUTHOR]

The ichnospecies Gastrochaneolites dijugus Kelly and Bromley 1984 and Teredolites longissimus Kelly and Bromley 1984, attributed to the boring activity of gastrochaenoid and pholadid bivalves, are described respectively from the Miocene Vilanova Basin and the Pliocene Almería-Níjar Basin. Miocene and Pliocene traces are preserved as positive casts associated to invertebrate shells and wood fragments, respectively; in both cases, the host substrate (shells and wood) has been lost almost entirely by different taphonomic processes (mainly dissolution). For the first time in the fossil record, the complete ichnogenetic sequence of these two ichnospecies is described and figured. [ABSTRACT FROM AUTHOR]

A new ichnospecies, Linichnus bromleyi, is described on bone substrate as the result of a very likely predator/scavenger interaction. L. bromleyi consists of a single groove with a non-serrated edge. This new ichnotaxon is compared with L. serratus which was defined as a single elongate serrate-edged groove. L. bromleyi has been identified over the surface of bones of marine mammals (in particular, cetaceans and pinnipeds) from two Pliocene outcrops of Andalusia, southern Spain. The new ichnospecies can be clearly related with a trophic interaction between sharks and marine mammals (mainly whales, dolphins and seals). [ABSTRACT FROM AUTHOR]

Marine mammal fossils (except pinnipeds) have commonly been found in Pliocene marine siliciclastic layers of the Neogene Guadalquivir Basin in Southwest Spain. A few Neogene phocid innominate bones are known from the Western Paratethys and Western Atlantic. Here we describe a new innominate bone from the early Pliocene (5.3–3.6 Ma) of the Western Paratethys (Spain), which is typical of the subfamily Monachinae, and has a flattened ilium similar to representatives of the tribe Lobodontini, particularly Leptonychotes weddellii. Comparison with other fossil monachine innominates from North America, South America and South Africa reveals that this specimen represents the genus Homiphoca, but species classification remains premature. This is the first European record of the genus Homiphoca and has paleobiogeographic implications, questioning the geological age of the Varswater Formation 'E' Quarry, Langebaanweg, Cape Province of South Africa. This discovery from the eastern North Atlantic further implies a more regular transatlantic gene flow in Miocene and Pliocene times than today. We argue that during the Messinian-Zanclean crisis, monachines became isolated and retreated southward to lower latitudes, possibly due to climatic deterioration (during glacial stages) and competition from the cold-adapted phocines from the north. Abbreviations: NMNH: National Museum of Natural History, Smithsonian Institution, Washington, DC., USA; CMM: Calvert Marine Museum, Solomons, Maryland (USA); UTM: Universal Transverse Mercator Coordinate system [ABSTRACT FROM AUTHOR]

Valencina (Seville, Spain) is one of the most important megalithic sites of the third millennium BCE in Western Europe. Among its most celebrated monuments are the tholoi of Montelirio, La Pastora, Matarrubilla, and Structure 10.042-10.049. Although sharing the same architectural tradition, these monuments were raised at different times of Valencina's history and present important formal differences. In particular, the tholoi of La Pastora and Matarrubilla contrast with that of Montelirio in that they are devoid of artistic ornamentation such as paintings and engravings, showing instead an inordinate number of natural geological features. This study, focusing on La Pastora and Matarrubilla, offers an innovative approach to the notion of "megalithic art." Firstly, these elements are characterized and classified and their natural origin established. Thus, the calcareous sandstone blocks dated from the Tertiary reveal structures on their surfaces generated by biological (bioturbation) and physical (by currents) processes during the Neogene. The surfaces of certain slabs of identical lithology at La Pastora experienced more recent intense marine bioerosion and bioconstructions in the form of Ostrea preserved to this date. Secondly, we emphasize the choice of different rock types following a certain pattern or serving to highlight a particular constructive element. In sum, all the natural elements bear highly aesthetic qualities and appear to have been deliberately chosen to highlight specific decorative or symbolic aspects. As a result, we suggest that future research on "megalithic art" should include analogous geological examinations in order to discern the origin and nature of the different elements. [ABSTRACT FROM AUTHOR]

A Late Pleistocene surface full of tracks and trackways (named 'Matalascañas Trampled Surface') has been exposed at the base of the 'El Asperillo' cliff (Doñana National Park, Matalascañas, Huelva, southwestern Spain) as a result of recent storms. This surface has been identified as the bottom of the unit AU1, according to the local stratigraphic section, and originated during the marine stage MIS-5 (∼106 ± 19 kyr). This trampled surface records exceptional tracks and trackways of different terrestrial vertebrates. In particular, three morphotypes of tracks ascribed to Artiodactyla (the auroch Bos primigenius ? the red deer Cervus elaphus and wild boar Sus scrofa), one to Elephantidae (Palaeoloxodon antiquus), one of Canidae (Canis lupus), and three to waterbirds (geese, Anserinae, and waders, Charadrii) have been identified. This ichnoassociation is characteristic of a shorebird ichnofacies. We interpret this trampled surface to have been related to puddled areas of shallow waters in an inter-dune position, similar to present day examples in the Doñana National Park. • The Late Pleistocene aeolian deposits on Matalascañas (SW Spain) contain abundant mammal and bird tracks and trackways. • These deposits form a lower set of cliff-foot dunes and another of rampant sands. • The fossil tracks and trackways are concentrated in two units dated by OSL in 106 ± 19 kyr (MIS 5). • The tracemakers identified are artiodactils, elephants, wolves, waterbirds and shorebirds. • The palaeoenvironmental interpretation of the surface is related to puddled areas of shallow waters in an interdune position. [ABSTRACT FROM AUTHOR]

Portus was the main port of imperial Rome from the 2nd century AD to the 5th century AD, with an inner, hexagonal port (Trajan basin) and an outer port (Claudius basin) linked by a channel bounded by quays. Six sedimentary facies have been differentiated in the geological analysis of a core extracted in this channel, basically composed of poorly classified bioclastic muds typical of restricted environments, accumulations of Posidonia oceanica (Linnaeus) Delile, 1813 and a final anthropic fill. The subfossil record of bivalves, foraminifera and ostracods is characteristic of Mediterranean brackish environments (lagoons, estuaries, deltas) with significant environmental stress, due to changes in the physical-chemical parameters and probably the periodic dredging of this seaway during a period of about 300 years. The presence of "Neptune balls" points to the development of probable stormy periods that deposit these unique structures in the internal areas of this historic port. [ABSTRACT FROM AUTHOR]