Browsing by Author "Rasser, Michael"
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- Miocene to recent rhodoliths of the Azores: systematics, palaeoecology and palaeobiogeographyPublication . Rebelo, Ana C.; Rasser, Michael; Neto, Ana I.; Ávila, Sérgio P.“[…]. The project aims to produce the first taxonomical study of the Late-Miocene-Early Pliocene rhodolith coralline algae for the Azores and to produce check-lists of the rhodolith coralline algae species by Island collected from selected outcrops. The outcrops will be studied geologically, chronostratigraphically and geochronologically in the frame of the project "The Route of the Fossils". Data sets will be used to establish the (palaeo)-biogeographical relationships between the Atlantic archipelagos (Azores, Madeira, Canaries and Cape Verde). The results will be compared with those of other marine organisms (mollusks, echinoderms, littoral fishes, bryozoans, ostracods). […]”
- Pleistocene coralline algal buildups on a mid-ocean rocky shore : Insights into the MIS 5e record of the AzoresPublication . Rebelo, Ana C.; Rasser, Michael; Ramalho, Ricardo S.; Johnson, Markes E.; Melo, Carlos S.; Uchman, Alfred; Quartau, Rui; Berning, Björn; Neto, Ana I.; Mendes, Ana Rita Marques; Basso, Daniela; Ávila, Sérgio P.Located on the northern coast of Santa Maria Island (Azores Archipelago, central North Atlantic), the Lagoinhas section preserves a carbonate buildup correlated with Marine Isotope Substage (MIS) 5e, the warmest interval of the Last Interglacial. The buildup is formed mainly by crustose coralline algae (CCA) identified as Spongites sp., and some subordinate crusts of Lithophyllum sp. and Neogoniolithon sp., as well as cf. Titanoderma sp. Extant CCA buildups are not recorded in the archipelago. Herein, we describe in detail the morphological and taphonomical features of the Lagoinhas CCA buildup and interpret the environment in which it grew. Additionally, this buildup is compared with another of similar age, exposed in the Prainha-Praia do Calhau section on the island's opposite southern coast. The hydrodynamic regime appears to play a crucial role in the development of Azorean CCA buildups during the MIS 5e.
- Rhodolith forming coralline algae in the Upper Miocene of Santa Maria Island (Azores, NE Atlantic) : a critical evaluationPublication . Rebelo, Ana C.; Rasser, Michael; Riosmena-Rodríguez, Rafael; Neto, Ana I.; Ávila, Sérgio P.The Late Miocene Malbusca outcrop is located in the southeastern coast of Santa Maria Island (Azores, NE Atlantic), interspersed in volcanic formations. At ~20 meters above present sea level, a prominent discontinuous layer of rhodoliths seizes with an extension of ~250 meters. This paper presents the first taxonomic record of fossil rhodolith forming coralline algae for the Miocene of the Azores. The preserved taxonomic features used were the following: (1) arrangement of basal filaments, (2) epithallial cells (when observable), (3) presence of cell fusions, (4) conceptacle type, (5) number of cells layers which conceptacle chamber floors are situated below the surrounding thallus surface and (6) for the sporangial pores, the orientation of the filaments around the conceptacle pores. Based on these characters, six taxa were identified encompassing three Corallinaceae (Lithophyllum prototypum, Lithophyllum sp., Spongites sp., Hydrolithon sp.) and one Hapalidaceae (Phymatolithon calcareum and cf. Phymatolithon sp.). An unidentified coaxial thallus was also present, the coaxial construction ascribing the specimens to the genus Mesophyllum or Neogoniolithon. Taxonomic accounts for the identified taxa are described, illustrated and an identification key is provided. The report of L prototypum represents the first Miocene record and the preservation of the specimens is very good. Miocene coralline algae seem very consistent among deposits but some species are relevant for particular areas, like in the Azores.