Biostratigraphie et paléoécologie des peuplements d'ostracodes dans le Domérien du Bassin Lusitanien, Portugal

The Domerian sections from the Lusitanian Basin of São Pedro de Muel, Rabaçal and Tomar have provided us with more than 1100 Ostracods belonging from 18 genus and about 48 species. The faunal diversity and density of the associations decrease in space (from Tomar to Rabaçal and São Pedro de Muel) and time, with favourable environments for the proliferation of Ostracods at the lower part of the sections (Stokesi subzone) and more hostile at the upper part (Ragazzonii subzone). The Monestieri and Nitescens horizons and the Subnodosus subzone are characterized by a typical assemblage of Ostracods. The palaeoecological Ostracod indexes reveal the fluctuations of the oxygenation, temperature, depth and hydrodynamism of the water, on the different sections and on the whole platform. They display a diachronous cooling in the Lower Domerian series. In the upper part of the Middle and in the Upper Domerian, the deeper, less oxygenated and cooler waters prevent the development of the Ostracod faunas.

Upper Jurassic Hybodontidae (Selachii) from Lourinhã, Portugal

Hybodontidae teeth and spines from the Lourinha Formation, Sobral unit are described. These teeth and spines have been ascribed to the genus Hybodus and regarded as Hybodus cf. reticulatus.

The Cenomanian-Turonian transition in West Central Portugal: ammonites and biostratigraphy

The Upper Cenomanian and Lower Turonian ammonite assemblages from the onshore sectors of the West Portuguese Margin are reviewed after new studies on the type section of Figueira da Foz, and correlative sections of Baixo Mondego. The faunal succession shows a strong contribution of vascoceratids and other ammonites with North African and Tethyan affinities. Euomphaloceras septemseriatum (Cragin, 1893), Kamerunoceras douvillei (Pervinquere, 1907), Fagesia catinus (Mantell, 1822), Neoptychites cephalotus (Courtiller, 1860), and Thomasites rollandi (Thomas & Peron, 1889) are for the first time mentioned to Portugal. The Upper Cenomanian is recognised after a set of 3 assemblage zones: Neolobites vibrayeanus z., Euomphaloceras septemseriatum z ., and Pseudaspidoceras pseudonodosoides z. The carbonate succession shows an important unconformity across the Cenomanian-Turonian boundary, associated to subaerial exposure, and to the development of a palaeokarst over Upper Cenomanian units. The first Lower Turonian carbonates are yielded a single but diverse ammonite assemblage of middle Lower Turonian age (Thomasites rollandi z.). This biozone was previously recognised in Central Tunisia by G. Chancellor et al. (1994).

Notes on the Cretaceous invertebrate faunas of Portugal I: a new species of Anadromus (Mollusca, Gastropoda) from the Campanian-Maastrichtian of Taveiro (Coimbra, West central Portugal)

A new species of terrestrial gastropod - Anadromus penai sp. nov. (Fam. Anadromidae) - is described from a set of composite moulds collected in reddish silts and clays of Campanian-Maastrichtian age, found in the lower pan of the Taveiro Formation (Taveiro, Coimbra, West Central Portugal). The known occurrences of this new species are restricted to the type locality. The main differences from other contemporaneous Anadromidae are the profuse spiral sculpture of the body-whorl, with 20-22 sub-equal, close, and regular ribs.

Upper Paleocene-Early Eocene mollusks of Silveirinha (Figueira da Foz, West Central Portugal)

A collection of fossil gastropods and bivalves assembled at the Thanetian/Ypresian vertebrate site of Silveirinha (Figueira da Foz, West Central Portugal) is analysed from the point of view of systematics and palaeoecology. The diversity is scarce but the age and exceptional characteristics of the site are factors that substantiate a detailed study. The taxa identified are: Bithynia soaresi sp. nov., Gyraulus antunesi sp. nov., Chlamys sp. and Cardiiacea gen. sp. indet. The prevailing of freshwater gastropods and the occurrence of 2 fragments of marine bivalves suggest a palaeoenvironmental setting that is in conformity with interpretations already established, which are based both in sedimentologic and vertebrate data. These interpretations point out the existence of a freshwater environment opened from time to time to marine influences, resulting from a palaeoatlantic coast placed some kilometres westwards.

Limnic ostracoda from Silveirinha, Portugal (? Late Paleocene - Lowermost Eocene)

Silveirinha, a rich site for mammals and other vertebrates, yielded some molluscs, charophytes and ostracods. The latter are described here. Eight species were recognized. Two of them, Ilyocypris lusitanicus n. sp. and Cypris silveirinhaensis n. sp. are new. Other, unnamed species may be ascribed to Cyclocypris? and Cypria? besides a further four undeterminate Cypridacea. The Ostracod association is typical for limnic environments and is compatible with intertropical conditions. Cypris silveirinhaensis suggests an Eocene, and especially a lower Eocene age.

Poissons du Paléogène inférieur de Silveirinha (Portugal)

Fragmentary skeletal remains of Percoid fishes (Teleostei, Percoidei) are described from the Upper Paleocene? or Lowermost Eocene(MN7) from Silveirinha. It is suggested that they belong to some primitive Percoids which are already known in the Iberian peninsula. They bear witness of an ancient westwards extension of the geographical distribution of Percoid fishes that are common in the lower levels of the Eocene in the Douro Basin in Spain.

Amphibians and squamate reptiles from the lower Eocene of Silveirinha (Portugal)

Silveirinha (Portugal) has produced a diverse herpetofauna. In Europe, it is the only described assemblage of amphibians and squamate reptiles from the base of the Eocene (MP 7). The fauna includes at least two species of amphibians (belonging to the Salamandridae and perhaps the Pelobatidae) and at least 15 species of squamates (at least nine families: Iguanidae, Agamidae, Gekkonidae, one or two families of scincomorphans, Anguidae, ?Varanidae, Amphisbaenidae, Boidae, Tropidophiidae, and likely an indeterminate family of snakes). But, except for the snake Dunnophis matronensis, identifications at species level are not possible. The presence of iguanid lizards and of the snake D. matronensis in the base of the Eocene (MP 7) of Europe is confirmed. The fauna includes several squamates that show close affinities with North American taxa.

Neochelys sp. (Chelonii, Erymnochelyinae), from Silveirinha, early Eocene, Portugal

Constituted of isolated fragments with a smooth decoration, the turtle material from Silveirinha is examined in order to define its sure belonging to Neochelys, by comparison with other smooth turtles which may be present during the Palaeogene of Europe (freshwater Testudinidae, Erymnochelyinae, Bothremydidae). The elements are compared with the already known Neochelys species of the Eocene European localities. Questions are made about the possible geographical migrations of turtles between South and North during the early Eocene of western Europe. The phyletic relationships cannot be established but the species, seeming new and one of the more primitive as a whole (after the preserved elements), is the older from the Iberian Peninsula.

Description de restes squelettiques de Latidae: Lates (?) sp. (Poissons téléostéens, Percoidei) du Miocène inférieur et moyen du bassin du Bas Tage (environs de Lisbonne, Portugal)

Several Lower and Middle Miocene localities in the Lower Tagus basin near Lisbon yielded Latidae fragmentary remnants. No really decisive character has been recognized that would allow us to state these remnants could surely be ascribed to the genus Lates Cuv. & Val., although we regard this as nearly certain. There are some differences between the Miocene latidae under study and the type species Lates niloticus L. this suggests us to report the concerned remnants to a Lates (?) sp. that could belong to a new, hitherto undescribed species. The occurrence of Lates in fluviatile or lagoonal beds in the Lower Tagus basin Miocene series is not at all surprising under a paleoeciological view point. Even less if account is taken of the presence in the same levels of Siluriforms remnants belonging to Bagridae and Ariidae, two families that are well represented in Africa. Bagrid spines have been found at Quinta das Pedreiras in association with Lates (?) sp. remnants. The Lates (?) sp. discovery in the Lower and Middle Miocene from the Lower Tagus basin results in extending to the West this genus' biogeographic distribution. It is indeed the first discovery of this genus on Europe's Atlantic coasts. No matter which was the geographic origin of these fishes, they had to migrate several hundreds of kilometers through marine waters before entering the Tagus' estuary. The association of Lates (?) sp. remnants with Siluriform ones that have an extant, broad repartition in Africa south of the Sahara points out to an African origin. These thermophyll fishes imigration along the Atlantic coasts from lberian Peninsula probably has been possible owing to a warm climatic event that allowed them to migrate ca. 5 degrees (in latitude) northwards in Burdigalian times.

Uppermost Miocene Lamniform Selachians (Pisces) from the Alvalade basin (Portugal)

This paper deals with Lamniform teeth collected in deposits from the Esbarrondadoiro Formation, Alvalade Basin in Southern Portugal. The following genera were recognized: Carcharias, Pseudocarcharias, Alopias, Isurus and Carcharocles. The species Carcharias acutissima is by far the most predominant, all other taxa being rare or very rare. This situation points to neritic, tropical to subtropical, rather shallow waters not far away from the coast. This is corroborated by the rarity of the associated, mainly pelagic, taxa. The ratio between C. acutissima and the remaining Lamniforms as a whole is markedly uneven between Esbarrondadoiro and the localities of Santa Margarida and Vale de Zebro. This suggests quite different environmental conditions, a matter that will require a more thorough examination taking into account all palaeontologic and geologic data.

The Deinotherium (Proboscidea, Mammalia): an abnormal tusk from Lisbon, the Miocene record in Portugal and the first appearance datum. Evidence from Lisbon, Portugal

An exceptionally favourable stratigraphic and chronologic context concerning the Miocene series in Lisbon allows us to stress that there are two successive data as far as the Proboscideans' immigration into western Europe is concerned: firstly, that of Gomphotheres, and later that of Deinotheres. The study of a Langhian (in age) tusk has shown that Deinotherinm havaricum was still present then. The time span of this species could be accurately recognized. A discussion on the genus Deinotherium is presented, as well as its occurrence in Portugal and on its ecologic meaning.

Sondagem de Belverde (Cenozóico, Península de Setúbal, Portugal). Diagrafias

In the aim of the project "Recognition of the Miocene of the distal region of the Lower Tagus Basin through a borehole with continuous sampling", Temperature, Natural Gamma Ray, Neutron (almost in all the borehole), Sonic, SP and SPR (in two small sections in upper and lower parts of the Miocene Series) geophysical logs were carried on. Interpretation of those logs and comparison with chronological, lithostratigraphical, micropaleontological and clay mineraIs data; helped in the definition of depositional sequences and to obtain paleoenvironmental reconstructions that could lead to a better understanding of the evolution of the Setúbal Península and Lisboa regions Miocene gulf. Log data agree with the lithologic succession observed in the Belverde borehole, essentially silty sandstones/sandy siltstones (with variable clay content) to clays, often with marly intercalations. Sonic logs (and Neutron logs, in general) reflect the sediments porosity. The higher acoustic velocities are often related to compact/massive layers as claystones and/or limestones and rather fossiliferous marly layers. Lower values are obtained for porous, silty sandstones (fossiliferous and with scarce clay content) and bio-calcareous sandstones. As indicative, we obtained the mean values of 2500-3000m/s for the higher velocities and 1300-1600m/s for the lowest ones. ln Natural Gamma Ray log, the radiation peaks can be correlated to often fossiliferous marly micaceous layers. Radioactive micas are present. It seems that the gamma peaks and the depositional sequences previously defined for the Lower Tagus Basin (see Antunes et al., 1999, 2000; Pais et al., 2002) can be correlated, taking also into account the whole available micropaleontological, palynological and isotopic evidence.

Ostracoda: database for the Neogene of Portugal

The "Ostracoda: database for the Neogene of Portugal", prepared under the Project "POCTl/36531/PAL/2000 - Studies on Portuguese Palaeontology / Post-Paleozoic", is presented. It provides information about 158 especies that have been recognized in sections and boreholes concerning Neogene units in Portugal.

A new dinosaur tracksite in the Lower Cretaceous of Portugal

A new Lower Cretaceous (Aptian-Albian) dinosaur tracksite at the Olhos de Água beach is described. It is the first vertebrate fossil finding ever found in the concerned unit, and yielded 128 tracks in 17 trackways within an area of ca. 80 square metres. Three tridactyl footprint morphotypes have been recognized: - Type I ("Iguanodontipus-like") - trackways D, F, K, J and P; - Type 2 (large theropod), although larger in size, typically from a Grallator-like theropod footprint, i.e , A, B, G, H and 0 trackways; - Type 3 (medium size theropod); M is the only track of this type. There are other, poorly preserved, unidentified trackways. The theropod, swinging trackway B was produced by an animal that was limping. The theropod track M starts eastwards but drastically changes westwards, speeding up at the same time; this dinosaur decided to turn around and run in the opposite direction. This site shows three main trackway directions: to the South, to the East, and westwards. Except for the trackway 0, large theropods A, B, G and H walked southwards. Perpendicularly to the se, ornithopods, small theropods and unidentified trackmakers walked towards East (5) and West (7). The segregation oftrackmakers and directions, with large theropod traekways southwards and other dinosaurs' west or eastwards, may mean that large theropods patrolled a walkway area to an important resource, most probably water, often frequented by ornithopods and smaller theropods. There is no evidence of social behavior or gregarism: footprints' overposition shows that the large, southwards walking theropods passed on different occasions. Three trackway sequences can be established by chronologic order.