Michael Dermitzakis

CYNOTHERIUM SARDOUS, AN INSULAR CANID (MAMMALIA: CARNIVORA) FROM THE PLEISTOCENE OF SARDINIA (ITALY), AND ITS ORIGIN

Abstract The endemic insular canid Cynotherium sardous has been known for 1 ½ centuries, yet its phylogenetic position remained unsolved. This was because inherited ancestral characters and acquired adaptations to different ecological pressures could not be separated. In this study the problem is approached again, with the use of morphological features that were either overlooked or could not be explained properly, combined with results from recent major revisions of canid phylogeny. It appears that Xenocyon is the ancestor of Cynotherium, and that this large hypercarnivorous canid, once on the island, faced a rather different menu consisting of small prey only. The subsequent necessary adaptation resulted in a smallsized dog whose dentition remained much the same, whereas its skull lost the typical fortifications seen in the other hypercarnivorous canids; these are considered superfluous for Cynotherium, which had to exchange big and strong prey for small and fast prey.

BRACKISH MARSH BENTHIC MICROFAUNA AND PALEOENVIRONMENTAL CHANGES DURING THE LAST 6000 YEARS AT THE COASTAL PLAIN OF MARATHON (SE GREECE)

The present study, based mainly on the analysis of foraminifers and ostracodes, provides evidence of paleoenvironmental changes on the coastal plain of Marathon (E. Greece) during the last 6.000 yrs. Three sedimentary units -lagoonal formations - were recognized and identified as A, B and C. They range in time between before 5500BP-3500BP, 3500BP-2500BP and 2500BP-recent, respectively. The study of the brackish marsh microfauna of the Marathon plain Holocene sediments reveals the presence, during the last 5500 yrs., of three distinct biofacies in the sedimentary units already established. Alternating mesohaline - oligohaline (MO), oligohaline - fresh water (OFW) and mesohaline - oligohaline to oligohaline - fresh water (MO-OFW) biofacies in the framework of the sedimentary units indicate a general trend landward along the plain suggesting a slowing of sea-level rise probably correlated with a relevant tectonic uplift. One prominent feature of this study is the clarification of the ecological preference of the species Trichohya1us aguayoi (Bermudez, 1935), which is dominant in oligohaline conditions under an influence of fresh water input (salinity less than 15 ‰).

PALEOBATHYMETRIC INTERPRETATION OF THE FISH OTOLITHS FROM THE LOWER - MIDDLE QUATERNARY DEPOSITS OF KEPHALLONIA AND ZAKYNTHOS ISLANDS (IONIAN SEA, WESTERN GREECE)

Fish otoliths are herein used to estimate the depositional depth of the Early - Middle Pleistocene deposits at SE Zakynthos and SW Kephallonia Islands (Ionian Sea, Western Greece), through comparison with the modern bathymetric distributions of the identified fish taxa. These estimates provide a more detailed picture of the depth variations for the Gelasian - Ionian stage interval in the study areas. The Lower Pleistocene marine deposits of the Gerakas Formation (SE Zakynthos Island, Ionian Sea) were deposited at average depths of 400-450 meters, with eustacy playing an important role in the depth variability, between 1.95-1.73 Ma. An uplifting episode, followed by subsidence takes place between 1.73-1.66 Ma, taking the area to 200-300 meters of depth, and then back to 400-500 meters. However, the area seems uplifted again to 200-400 meters later on in the Calabrian stage (1.25-0.97 Ma). Sedimentation of the Akrotiri deposits (NW Kephallonia Island, Ionian Sea), during the same chronostratigraphic interval, took place in a similar setting. At the Early Pleistocene (1.95-1.73 Ma) this basin reached depths of 400-450 meters, with uplift and following subsidence taking place between 1.73-1.66 Ma. Overall, the application of fish otolith paleobathymetry in the study areas provide a detailed picture of the depth variations for the Early Quaternary interval and refine the currently hypothesized pattern of tectonic movements.

Foraminiferal stratigraphy and palaeoecological implications in turbidite-like deposits from the Early Tortonian (Late Miocene) of Greece

The Lower Tortonian Ag. Giannis section, in Gavdos Island, Greece, consists of an outer neritic to upper bathyal, marly hemipelagic sequence which is interrupted by thick turbidite-like sandy deposits. During deposition of the marly intervals, reworking was considerably reduced. This paper contributes to knowledge concerning benthic foraminiferal response to dynamic sedimentary environments. Important palaeoecological information for benthic foraminiferal assemblages was gathered and analyzed in order to create a regionally consistent picture of the palaeoenvironment. Samples were analyzed statistically in order to identify the different palaeoenvironmental settings during turbiditic sedimentation. Undisturbed basal marls of the section are characterized by the predominance of a diversified Uvigerina striatissima assemblage typified by a broad variety of morphotypes with different inferred habitat preferences and feeding strategies, indicating rather well-oxygenated bottom waters. This environmental stability was subsequently disrupted by recurrent deposition of turbidite-like sands. A low-diversity Valvulineria complanata-Globobulimina sp. assemblage is dominant in this part of the succession, as these specialized endobenthic species could keep pace with high-energy sedimentary settings. Just above the turbidites, a “recolonization” fauna (Bolivina alata assemblage), composed entirely of infaunal elements is observed, indicating a nutrient-rich substrate. This oligotypic fauna is later replaced by a more diversified microfauna capable of occupying a wider range of ecological niches.

DENTAL ERUPTION SEQUENCE IN THE PLIOCENE PAPIONIN PARADOLICHOPITHECUS ARVERNENSIS (MAMMALIA: PRIMATES) FROM GREECE

Paradolichopithecus is, together with Procynocephalus of Eastern Asia, the largest Eurasian monkey of the Pliocene. This Pliocene papionin is a derived macaque and probably the sister taxon of Macaca (Strasser and Delson, 1987), but has the body mass of the largest baboons (Mandrillus sphinx, P. ursinus, Theropithecus gelada). In morphology, it resembles macaques cranially and baboons postcranially (Szalay and Delson, 1979: 367). In cranial proportions Paradolichopithecus superficially resembles Papio, but when allometric factors are considered, it resembles more Macaca (Delson and Frost, 2004:22). Fossils of Paradolichopithecus in Europe are found in humid and closed localities in the Early Pliocene but in more arid and open localities in the Late Pliocene, reflecting its ability to adapt in pace with climatic trends in Europe (Eronen and Rook, 2004). The distribution of the genus is from the Early Pliocene in Europe and western Asia (Eronen and Rook, 2004) to the Early Pleistocene in eastern Asia (Deng et al., 2004:12). In 1998 a juvenile mandible of Paradolichopithecus arvernensis was discovered by Paul Sondaar in a Late Pliocene locality of Greece (De Vos et al., 2002). The locality (Vatera, F-site) is situated on southern Lesvos, an island close to the coast of Asia Minor, to which it was connected during the entire Pliocene. The finding gives us the opportunity to investigate aspects of the life history of this fossil monkey. Life history is a fundamental issue in vertebrate paleontology. Life history has been analyzed for the majority of extant primates, starting with the phenomenal work of Schultz (1935). The life history of a species includes milestones such as its age at sexual maturity, age at death, and age at other events in an individual’s lifetime that influence reproductive traits.

Petrology and Diagenetic Changes in Miocene Marine Diatomaceous Deposits from Zakynthos Island, Greece

Silica diagenesis in a diatomaceous section of marly limestone and chert from central Zakynthos Island, Ionian sea, was investigated. This section, underlain by Cretaceous-Eocene reefal limestone and overlain by a middle-upper Miocene terrigenous—evaporitic succession, is defined as the Romiri Formation. Diatom and planktonic foraminiferal assemblages occur, the latter determining the biostratigraphic interval N4-N7 of the Blow zonation (Aquitanian-Burdigalian).

Fossil Folklore from India: The Siwalik Hills and the Mahâbhârata

All over the world, from antiquity to the present, people have often explained fossil discoveries as proof of the historical truth of legends and myths, or used them as a basis for a new legend. Most often, large vertebrate fossils have been explained as bones and teeth of giant humans, dragons and monsters, saints and heroes. Smaller invertebrate fossils were often interpreted as sacred or curious relics based on their resemblance to familiar or sacred objects. India is no exception to this practice. Fossil ammonites (salagramas), for example, are worshipped as the disc (chakra) of the Hindu god Vishnu. The Siwalik Hills, below the Himalayas, are strewn with impressive Plio-Pleistocene vertebrate fossils. This paper suggests that the region was seen as the historical stage for the legendary battle as described in the Indian epic Mahâbhârata, during which hundreds of mighty, and sometimes gigantic, heroes, horses, and war elephants are said to have died. Their remains are seen in the fossil bones, skulls, jaws, and tusks of hippopotamuses (Hexaprotodon), proboscideans (Stegodon, Archidiskodon), four-horned giraffes (Sivatherium, Giraffokeryx), giant tortoises (Geochelone), sabre-toothed cats (Paramachairodus), camels (Camelus), and other species found on the surface of the Siwalik Hills. Moreover, thousands of ancient bronze javelins and spears are also found there after rains. These archaeological artefacts, along with the paleontological remains, appear to have influenced the setting and context of the great battle in the Indian epic.

The response of benthic foraminifera to palaeoenvironmental disturbance: A quantitative approach in turbidite-like successions

Benthic foraminifera were collected from a number of samples of a turbidite-like succession, and quantitatively investigated with the aim to describe and interpret their distributional pattern prior, during and after the turbidite events. The foraminiferal assemblages contain indigenous benthic taxa that represent combined bottom-water and bottom-sediment controlled benthic environments and allochthonous benthic shelf taxa that are transported downslope into deeper-water biotopes. Considerable differences in diversity, community organization, feeding and habitat preferences are detected among benthic foraminiferal assemblages below, across and above the turbiditic episodes. Prior to the deposition of the turbiditic sands, the benthic foraminiferal assemblage is indicative of a strong preference of environments with highly elevated food supply, but sheltered from direct disturbance. This stability was disrupted by the recurrent deposition of turbiditic sands. In the lower part of the turbiditic sequence, some specialized endobenthic forms, such as Valvulineria complanata and Nonion spp. could keep pace with high sedimentation reflecting enhanced supply of organic matter by transport. In the upper part of the turbiditic sequence, an opportunistic fauna (Bolivina spathulata assemblage), entirely composed of infaunal elements, is observed, indicating a nutrient-rich substrate. The reduction in the dominance of Bolivina spp. and the reappearance of both infaunal and epifaunal taxa reflects the recovery of the benthic ecosystem.