Carlos Melo

The Palaeontological Heritage of Santa Maria Island (Azores: NE Atlantic): a Re-evaluation of Geosites in GeoPark Azores and Their Use in Geotourism

The application of geoconservation concepts and methodologies to the Azores archipelago led to the implementation of the Geopark Azores, recognized as such by the European and Global Geoparks Network. The current work re-evaluates and stresses the scientific and touristic value of the palaeontological sites of Santa Maria Island. Two new geosites (the Ponta do Castelo tempestite deposit and the Pedra-que-pica coquina) are proposed for classification as ‘Regional Natural Monuments’ by the Regional Government of the Azores, due to their international relevance. The tempestite deposit of Ponta do Castelo was overlain by a contemporary coastal lava delta, which enables the inference of the precise water depth of the geosite at the time of deposition, a very rare condition worldwide; and Pedra-que-pica is the most extensive multispecific fossiliferous coquina ever reported in the literature from the shelf of any of the ∼20,000 known volcanic oceanic islands in the world. Relevant geosites reported for this island are increased from 15 to 26. Additional palaeontological heritage contributions to the sustainable tourism of Santa Maria are suggested, with a focus on two recent projects: the ‘Fossil Trail’ and the future ‘PalaeoPark Santa Maria’.

Diagenetic history of lower Pliocene rhodoliths of the Azores Archipelago (NE Atlantic): Application of cathodoluminescence techniques

The diagenetic history of calcareous fossils is required for their application as palaeoenvironmental indicators. In this study, cathodoluminescence-microscopy (CL microscopy) and back scatter electron image-energy dispersive X-ray spectroscopy (BSE-EDS microscopy) were applied to Pliocene rhodoliths from the Azores Archipelago (NE Atlantic) in order to gain additional insight regarding the trace element content distribution throughout the algae thalli, and to ascertain palaeoenvironmental interpretations. Two types of luminescence were obtained: (1) high and (2) low luminescence. Rhodoliths with high luminescence are related with high concentrations of Mn(2+) in seawater and low luminescence rhodoliths are related with low concentrations of Mn(2+) in seawater. When the rhodoliths were deposited at about 4.0-4.5 Ma, the shoreline configuration of Santa Maria Island was much different than today. The influence of volcanic activity due to the extrusion of lavas and associated products and/or the presence of active shallow-water hydrothermal vents, was reflected in the sea water chemistry, with penecontemporaneous palaeoshores of the island featuring a high sea water concentration of Mn(2+), which mirrored on the rhodolith Mn(2+) high concentration. By contrast, rhodoliths located about 2.8 and 2.9 km from the shore, in areas with low seawater Mn(2+) concentration, had low luminescence, reflecting the low Mn(2+) concentration in seawater. Rhodoliths chemical data and the geological history of the island proved to be congruent with the palaeogeographical reconstruction of Santa Maria Island at the time of the formation of the rhodoliths.

Fossil Mysticeti from the Pleistocene of Santa Maria Island, Azores (Northeast Atlantic Ocean), and the prevalence of fossil cetaceans on oceanic islands

Fossil remains of Cetacea are known globally from nearshore marine sediments along continental coastlines, but they are poorly known from volcanic oceanic island archipelagos. Here we report Pleistocene fossil cetacean material from late Neogene and Quaternary age outcrops on the Santa Maria Island of the Azores island archipelago in the North Atlantic Ocean. These remains consist of an isolated and highly worn fragment from the mandible of a mediumto large-sized baleen-bearing mysticete (i.e., Chaeomysticeti), which was exposed at the marine isotope stage 5 (sub-stage MIS 5e) level at Praia do Calhau, after Hurricane Gordon hit Santa Maria Island in August 2012. While this occurrence represents only the second description of Pleistocene cetaceans from volcanic oceanic islands, we predict that fossil cetaceans are likely underreported from oceanic islands, given their extant abundance and richness near oceanic island archipelagos today, whose geomorphology and oceanography provide important settings for the migration and life history patterns of living cetaceans. Sergio P. Avila. CIBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, InBIO Laboratorio Associado, Polo dos Acores, Departamento de Biologia da Universidade dos Acores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Acores, Portugal; and MPB-Marine PalaeoBiogeography group, University of the Azores, Ponta Delgada, Portugal; and Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. avila@uac.pt Ricardo Cordeiro. CIBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, InBIO Laboratorio Associado, Polo dos Acores, Departamento de Biologia da Universidade dos Acores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Acores, Portugal; and MPB-Marine PalaeoBiogeography group, University of the Azores, Ponta Delgada, Portugal. rjpcordeiro@gmail.com Ana R. Rodrigues. Departamento de Biologia da Universidade dos Acores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Acores, Portugal. arprodrigues.17@gmail.com Ana C. Rebelo. CIBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, InBIO Laboratorio Associado, Polo dos Acores, Departamento de Biologia da Universidade dos Acores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Acores, Portugal; and MPB-Marine PalaeoBiogeography group, University of the Azores, Ponta Delgada, Portugal; and SMNS Staatliches Museum fur Naturkunde Stuttgart, Rosenstein 1, D-70191 Stuttgart, Germany. PE Article Number: 18.2.27A Copyright: Paleontological Society June 2015 Submission: 3 March 2015. Acceptance: 22 May 2015 Avila, Sergio P., Cordeiro, Ricardo, Rodrigues, Ana R., Rebelo, Ana C., Melo, Carlos, Madeira, P., and Pyenson , Nicholas D. 2015. Fossil Mysticeti from the Pleistocene of Santa Maria Island, Azores (Northeast Atlantic Ocean), and the prevalence of fossil cetaceans on oceanic islands. Palaeontologia Electronica 18.2.27A: 1-12 palaeo-electronica.org/content/2015/1225-oceanic-island-fossil-cetacean AVILA: OCEANIC-ISLAND FOSSIL CETACEAN acfurtadorebelo@gmail.com Carlos Melo. MPB-Marine PalaeoBiogeography group, University of the Azores, Ponta Delgada, Portugal; and Departamento de Geociencias da Universidade dos Acores, Campus de Ponta Delgada, 9501-801 Ponta Delgada, Acores, Portugal. casm.azores@gmail.com Patricia Madeira. CIBIO, Centro de Investigacao em Biodiversidade e Recursos Geneticos, InBIO Laboratorio Associado, Polo dos Acores, Departamento de Biologia da Universidade dos Acores, Campus de Ponta Delgada, Apartado 1422, 9501-801 Ponta Delgada, Acores, Portugal; and MPB-Marine PalaeoBiogeography group, University of the Azores, Ponta Delgada, Portugal. tamissa@hotmail.com Nicholas D. Pyenson. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, NHB, MRC 121, PO Box 37012 10th & Constitution NW Washington, DC 20013-7012, USA. PyensonN@si.edu

FEEDING TRACES OF RECENT RAY FISH AND OCCURRENCES OF THE TRACE FOSSIL PISCICHNUS WAITEMATA FROM THE PLIOCENE OF SANTA MARIA ISLAND, AZORES (NORTHEAST ATLANTIC)

Abstract The bowl-shaped trace fossil Piscichnus waitemata Gregory 1991 appears in Pliocene sandstones from Santa Maria Island (Azores Archipelago), extensively excavated during a stage of island evolution when the volcanic edifice was a guyot (flat-topped seamount) isolated in the NE Atlantic. The host sediments were deposited at depths from the intertidal zone to fair-weather wave base in a tropical climate under the influence of periodic storms and hurricanes. The traces were produced by ray fishes hunting for polychaetes, crustaceans and bivalves living in the sediment, similar to present-day nearshore, warm waters in the Azores, Baja California Sur (Mexico), and New Zealand, from which examples of feeding depressions are drawn (incipient Piscichnus). While P. waitemata is abundantly present in planar sediments on top of the guyot, far fewer trace fossils occur in sandstone deposited on the guyots margins. Presumably, the different densities of ray holes in the two sedimentary bodies were a response to lesser availability of prey, lower seawater temperatures (due to greater depths), and a more dynamic environment in which life conditions were less favorable. Moreover, the potential preservation of bowl-shaped depressions was lower in this setting, given the steepness of the seafloor, stronger currents, and constant sediment mobility. The top of the guyot was a more favorable habitat, refuge and/or nursery ground for many ray fishes. Measurement of the diameters of the ray holes indicate three distinct size classes, which may suggest that several species were responsible for their formation.

Global change impacts on large-scale biogeographic patterns of marine organisms on Atlantic oceanic islands

Past climate changes provide important clues for advancement of studies on current global change biology. We have tested large-scale biogeographic patterns through four marine groups from twelve Atlantic Ocean archipelagos and searched for patterns between species richness/endemism and littoral area, age, isolation, latitude and mean annual sea-surface temperatures. Species richness is strongly correlated with littoral area. Two reinforcing effects take place during glacial episodes: i) species richness is expected to decrease (in comparison with interglacial periods) due to the local disappearance of sandy/muddy-associated species; ii) because littoral area is minimal during glacial episodes, area per se induces a decrease on species richness (by extirpation/extinction of marine species) as well as affecting speciation rates. Maximum speciation rates are expected to occur during the interglacial periods, whereas immigration rates are expected to be higher at the LGM. Finally, sea-level changes are a paramount factor influencing marine biodiversity of animals and plants living on oceanic islands.