BAND_03

Band 36

Uwe Gloy & Rolf Kohring (Hrsg.)

Miscellanea Palaeontologica 9.

Berliner geowissenschaftliche Abhandlungen, E 36:

242 S., 27 Taf. Berlin 2001.

INHALTSÜBERSICHT

 

Dimitris Frydas & Helmut Keupp

Upper Cenozoic calcareous and siliceous phytoplankton stratigraphy for marine sediments in central Crete, Greece.

Abstract

Fine laminated diatomic beds in outcrops of the Finikia unit (Estavromenos and Athanatoi sections) in the northern part of the Heraklion district in Crete, have yielded a total of 55 marine diatoms and 24 silicoflagellate taxa. The diatom assemblages are characterized by species of low latitudes. They belong to the upper part of the Nitzschia jouseae biozone (Early Pliocene-Late Pliocene) because of the presence of the marker species N. jouseae. The silicoflagellate associations belong to the local Dictyocha fibula ausonia and Dictyocha hellenica subzones. These subzones correspond to the subzones CN11b (Discoaster asymmetricus) and CN12a (D. tamalis) of calcareous nannofossils respectively, as well as to the Globorotalia puncticulata/G. bononiensis biozones of planktonic foraminifera. The sparse silicoflagellate association from fine sandy marls of the Panassos section in the southern part of the Heraklion district, which belongs to the Upper Tortonian-Messinian Aghia Varvara unit, were placed at the local biozone Distephanus speculum minutus. This biozone corresponds more or less to the biozone C9 (Discoaster quinqueramus) of calcareous nannofossils and to the Globorotalia conomiozea zone of planktic foraminifera. No discoidal diatoms could be found in the samples from Panassos-section. The differences in existence of silicoflagellates by simultaneous missing of diatoms is due to the greater opal dissolution within the fine sandy marls of the Panassos section.

 

Dimitris Frydas & Helmut Keupp

The Miocene/Pliocene boundary in NW Crete by means of calcareous nannofossil assemblages.

Abstract

Well determined calcareous nannofossil assemblages consisting of biostratigraphical index species have decisively contributed to define the boundary Miocene/Pliocene through the Vlacheronitissa and Kontomari sections along the new national road Chania-Kolymbari at north-western Crete. The subzone CN10a (sensu Okada & Bukry 1980) can be subdivided in two stratigraphical intervals. The first one (CN10a1) is characteristic with the common occurrence of Discoaster intercalaris and D. mendomobensis by absence of D. quinqueramus. The second interval (CN10a2) is marked by the simultaneously first appearance of Ceratolithus acutus and C. armatus just at the boundary Upper Messinian/ Lower Zanclean at 5.34 Ma (sensu Shackleton et al. 1995).

 

Dimitris Frydas

Silicoflagellates of the Late Quaternary Sapropel S5 from the Southeastern Mediterranean Sea, "Meteor"-Cruise 40/4, Site 69.

Abstract

Marine phytoplankton silicoflagellates have a geologic record from the Mesozoic through the Cenozoic. Their siliceous skeletons can be used as indicators for paleoceanographic currents and upwelling, relative paleotemperatures, and for local and transoceanic biostratigraphic zonations. Deep-ocean-coring during the past quarter century has expanded the potential and applications for silicoflagellates to many new areas. Well to moderate preserved siliceous phytoplankton assemblages containing silicoflagellate discovered in the diatomaceous sapropel S5, site 69 (M40/4; 33°51, 57'N, 24"41,45'E; 2.154 m water depth) were studied and quantitatively analyzed. The silicoflagellate assemblage is generally composed of warm-water Dictyocha species. The stratigraphical interval of the investigated sapropel layer S5 belong to the Dictyocha aculeata aculeata biozone. This stratigraphical interval corresponds to the lower part of the oxygen isotope stage 5 (about 125 ka). Paleoecological evaluation of the phytoplankton indicate that silicoflagellate occupied various ecological niches. In addition, bacterial activities were found in the deepest samples of sapropel S5 which themselves must provide favorable conditions for the growth and survival of chemotropic bacteria as H2S. The bacterial action attacks the outer surface layer of silicoflagellate and dissolution takes place.

 

Joachim Gründel

Neritimorpha und weitere Caenogastropoda (Gastropoda) aus dem Dogger Norddeutschlands und des nordwestlichen Polens.

Abstract

From the Middle Jurassic of northern Germany and northwestern Poland (including the erratic boulders from Middle Jurassic age) 1 species of the Neritimorpha and 30 species of the Caenogastropoda are described. New are 7 species. 14 species belong to already known species and 10 species are described under open nomenclature. New are also the genus Bicorempterus (Aporrhaidae) and the families Naricopsinidae, Tripartellidae and Maturifusidae. The described Caenogastropoda have more relationships to already known faunas from the Middle Jurassic of Middle and Western Europa as the Archaeogastropoda and the Heterostropha. The identification from species described in this paper with already known species is often problematic. Taxonomic important details especially from the first whorls and the infraspecific variation have been not described in the most cases. Vatopsis antiquus sp. n. is the oldest better known member of the Cerithiopsoidea. Pictavia and Oonia belong to the family Ampullospiridae (development of the protoconch). Naricopsina and related forms are a separate group and possibly the ancestor of the true Naticidae. A more exact diagnosis is given for some genera of the Aporrhaidae. Maturifusus is the oldest known representative of the higher Caenogastropoda (Neomesogastropoda).

 

Rolf Kohring

Nonmarine trace fossils from the Bathonian (Middle Jurassic) of Msemrir (Central High Atlas, Morocco).

Abstract

Alluvial and lacustrine sediments from the Guettioua Formation (Middle Jurassic) of the Central High Atlas in Morocco contain a multitude of well preserved trace fossils. Due to the represented taxa, this nonmarine ichnocoenosis can be assigned to the Scoyenia ichnoguild. Three formal ichnotaxa are recognized: Scoyenia gracilis, Skolithos isp., and Scolicia isp. Three more ichnotaxa (?arthropod trackways, fusiform burrows, and Ophiomorpha-like burrows) are also present. Distribution of trace fossils seems to depend mainly on availability and relevant energy level of water.

 

Uwe Gloy: Bibliographie 2000

 

"Biologie und Paläobiologie der Cephalopoden: Bilanz und Ausblick"

Treffen deutschsprachiger Cephalopodenforscher vom 8. bis 9. März 2001 an der FU Berlin

 

Helmut Keupp & Kerstin Warnke

Biologie und Paläobiologie der Cephalopoden: Bilanz und Ausblick

 

Sigurd v. Boletzky

Paläobiologie der Cephalopoden - vom Petrefaktischen zur Frage: "Wie hat das Tier gelebt?"

Abstract

The title of this essay, Paleobiology of cephalopods - from fossil evidence to the question: "how has the animal lived?", calls to mind the stepwise approach of paleobiology, which starts from the observation of fossil remains of organisms, endeavours to interpret them in light of taphonomy and diagenesis, then attempts to reconstruct the missing parts, and finally synthesizes a conceivable animal and its life in an environment again tentatively reconstructed. Paleobiology deals with conditional features, relations and processes, and therefore can provide only circumstantial evidence. Knowledge of the biology of extant species merely permits the formulation of hypotheses on the biology of ancient life forms. As with living species, the biology of extinct species must be viewed as the outcome of complex, time dependent patterns and processes generating reproductive cycles. Notwithstanding the very detailed knowledge of a few "model" species, the functional morphology, physiology and behavioural ecology of developing individuals prior to, and of adults at, the time of reproduction is still poorly known in the majority of extant cephalopods. The embryonic development and the early post-hatching and juvenile phases of many common species are only beginning to be studied thoroughly. Thus the neontological data base available is very limited and often shifting. A few examples are chosen to illustrate the relative frailness of our "biological knowledge" of living cephalopods, underlining the necessity for paleontologists and neontologists to intensify cooperation.

 

Günter Schweigert & Gerd Dietl

Die Kieferelemente von Physodoceras (Ammonitina, Aspidoceratidae) im Nusplinger Plattenkalk (Oberjura, Schwäbische Alb).

Abstract

In situ finds of ammonite beaks of Physodoceras (Aspidoceratidae) from the Late Kimmeridgian Nusplingen Lithographic Limestone are described besides exceptionally preserved isolated wing-like upper jaws and calcified lower jaws (Laevaptychi). A reconstruction of the upper jaw is presented. A single isolate specimen of an organic layer which was provable originally lying on the concave side of the Laevaptychus exhibits muscle or bend structures. They were most probably responsible for the retraction of the jaw apparatus into the body chamber. The possible function of both upper jaw and the corresponding aptychus is discussed mainly based on their morphologies. We again favour a beak function of the aptychi instead of an operculum or even a double function.

 

Christian Klug & Dieter Korn

Epizoa and post-mortem epicoles on cephalopod shells - Devonian and Carboniferous examples from Morocco.

Abstract

Twelve Devonian and Carboniferous cephalopods from the eastern Anti-Atlas (Morocco) with epizoa and post-mortem epicoles are described. Overgrowth of auloporoid encrustations on the conchs of some late Emsian ammonoids indicates occasional syn-vivo infestation of these cephalopods. In contrast, the arrangement of approximately 60 Serpularia tubes on the conch of a Carboniferous orthoconic cephalopod implicates a post-mortem encrustation. For the first time, post-mortem overgrowth by a cystoid (Eucystis sp.) of a Devonian ammonoid is described.

 

Ute Richter

Spuren der Weichkörperverlagerung auf Pyritsteinkernen von Ammonoideen.

Abstract

One can observe traces of softbody translocation on well preserved pyritized moulds of ammonoids formed during the chamber formation cycle. These traces are called tracking structures ('Schleppstrukturen') and consist of phantom sutures ('Geisterlobenlinien'), pseudosutures and tracking bands, like umbilical tracking bands ('Nabelbänder') and siphonal bands ('Siphonalstreifen'). Different tracking structures can be observed on goniatites, ceratites and ammonites. Phantom sutures and pseudosutures are typical tracking structures of goniatites and correspond to the attachment sites of the septal and mantle myoadhesive band. Phantom sutures were left during foward movement of the anterior mantle myoadhesive band in the body chamber. Pseudosutures were left on the inner wall of the phragmocone during translocation of the rear septal mantle. Umbilical bands, siphonal bands and sutural tracking bands associated with the lobes of the suture lines are typical tracking structures of ammonites. Umbilical and siphonal bands were formed during forward movement of the ventral and dorsolateral retractor muscles. Sutural tracking bands were left during forward movement of the septal myoadhesive mantle and can be interpreted as attachment points of parts of the mantle margin corresponding to the incisions of the sutures during soft body translocation. Ceratites combine typical tracking structures of goniatites (pseudosutures) with such structures of ammonites (sutural tracking bands that correspond to the lobes of the suture lines). The stepwise translocation of the lateral cephalic retractor muscles is characteristic in goniatites and ammonites. Tracking structures indicate different mechanisms of soft body translocation in goniatites and ammonites. In goniatites the soft body moves stepwise in constant intervalls, interrupted by short time intervalls without movement. In ammonites the soft body moves stepwise and/or continuous without interruptions. A continuous translocation leaves continuous tracking bands like umbilical and siphonal bands. A stepwise translocation leaves rows of crescent shaped structures. At last tracking structures indicate different viscoelastical properties of the septal mantle in goniatites, ceratites and ammonites. The goniatite rear septal mantle was stiff. During translocation it was completely detached and reattached stepwise. In ammonites the rear septal mantle was of highly viscoelastic nature. Only parts of the mantle margin were attached. They correspond to the incisions of the suture lobes during soft body translocation. The rest of the septal mantle margin was completely detached. When the position of the new septum was reached the detached parts were 'pulled' in form of the preceeding septum with the help of muscles. Finally the whole rear septal mantle was completely reattached.

 

Kerstin Warnke, Jörg Plötner, José Ignacio Santana, Maria José Rueda & Octavio Llinas

Zur Phylogenie rezenter Cephalopoden - Erste Ergebnisse einer molekular-genetischen Analyse des 18S rRNA-Gens.

Abstract

First results of a molecular study on phylogenetic relationships of recent cephalopods are presented. We determined the DNA sequence diversity of five cephalopod species (Loligo vulgaris, Sepia officinalis, Illex coindetii, Octopus vulgaris and Eledone moschata) from the Mediterranean (Banyuls, France), of Histioteuthis spec. from the West Atlantic Ocean (Fuerteventura, Canary Islands) and of Nautilus pompilius from the West Pacific Ocean (Philippine Islands) using a fragment (about 400 bp) of the small subunit of the nuclear ribosomal 18S rRNA gene. The results confirm the monophyly of the recent Cephalopoda, Coleoidea, Octobrachia, and Decabrachia. The phylogenetic relationships within the Decabrachia, however, could not be resolved on the basis of our sequence data. Further sequences are needed to obtain additional phylogenetic relevant information and to be able to calibrate a molecular clock for cephalopods.

 

Dieter Korn & Christian Klug

Biometric analyses of some Palaeozoic ammonoid conchs.

Abstract

The expansion rates of the whorl spiral, the whorl cross section surface, the whorl height, and the whorl width of a series of Palaeozoic ammonoids were computed. According to these expansion rates, differences between the major ammonoid groups can be recognised. The suborders Agoniatitina, Gephuroceratina, and Paraceltitina as well as the order Prolecanitida show intense changes in and produce high expansion rates, whereas the representatives of the suborders Anarcestina, Pharciceratina, Tornoceratina, as well as Goniatitina usually produce low expansion rates. The order Clymeniida displays a rather indifferent picture, but the expansion rates are usually rather low.

 

Gernot Arp

Fazies, Stratigraphie und Ammonitenfauna des Mittleren und Oberen Dogger bei Neumarkt i.d.Opf. (Bajocium-Oxfordium, Süddeutschland).

Abstract

A 25 m thick section of shallow-subtidal early Bajocian sandstones to early Oxfordian limestone-marl-alternations with sponge-microbialite-buildups of the middle shelf has been investigated at Neumarkt i.d.Opf. (Franconian Alb, Bavaria). The ammonoid faunas prove the presence of the Humphriesianum-, Parkinsoni-, Koenigi-, Jason-, Lamberti- und Bifurcatus-Zone. Further ammonite zones should be present as derived from correlation with the adjacent section Sengenthal. A biostratigraphic gap is evident only for the Upper Bathonian to the early Lower Callovian. The microfacies of the sediments reflects the increasing distance to the coast and a change in palaeogeography including the connection of the south German and Polish seas by the Regensburg strait, change in currents and a progressive opening to the Tethys. A step-by-step increase in water depth is suggested. Changes in thickness of the Bajocian-Bathonian at short distances result from a submarine erosional relief formed during the lowermost Bajocian. Iron ooids probably formed at the sediment-water interface in an poorly agitated environment. Disconformities and condensations in the early Bajocian to early Oxfordian are considered to result from transgressive pulses and sea-level highstands. In the case of the Parkinsoni- to early Zigzag-Zone, the early Koenigi-Zone and the Lamberti-Zone these condensations coincide with eustatic sea-level highstands. In addition, late parts of transgressive pulses and sea-level highstands are characterized by the formation of phosphorite. A regression is only indicated for the late Sauzei/ early Humphriesianum-Zone. The change from limonite- to glaucony in sedimentation coincides with the opening of the Regensburg strait during the Lower Callovian.