Bollettino SPI Vol. 27 - Issues 1, 2, 3
Issue 1
Published in March 1988
- Delle Cave L. (1988)
Jaxea cf. nocturna (Crustacea, Decapoda, Anomura) from the Early Pliocene of Tuscany, Italy
pp. 3-10
Thirty fragmented adult specimens identified as Jaxea cf. nocturna Nardo are collected from marine beds, preserved in clayey-silty deposit. They show linea thalassinica and cervical groove on the cylindrical carapace, telson with double longitudinal keel, first pereiopods elongate, isochelate.
We can suppose that the genus Jaxea, after the complete destruction of the Mediterranean fauna during the Messinian crisis of salinity, was reintroduced from the Atlantic. The finding of Jaxea in the Pliocene of Tuscany and its recent distribution suggest that the genus escaped the Mediterranean selective extinction phenomena which occurred during the Pliocene and Pleistocene.
Jaxea cf. nocturna with associated recorded fauna seem to document a palaeocommunity referable to the present « VTC » after Pérès & Picard in the «Circalitoral stage » in the Early Pliocene.
The pattern of the recent distribution of the genus Jaxea is correlated with water temperatures and discussed.
- Mainelli M. (1988)
A case of anomalous form in free valve of Durania sp.
pp. 11-16
A very anomalous form in left valve of Durania sp. is described.
The specimens, whose right valve is unknown: 1) are found out in upper Cenomanian of Mount La Costa (S. Polo Matese, Campobasso) in
a bioclastic limestone; 2) present an abnormally explained as a polyphenism in a Durania sp. population.
This population is not identified yet.
- Senowbari-Daryan B. & Di Stefano P. (1988)
Amblysiphonella maxima n. sp., a new Sphinctozoan sponge from Upper Triassic reefs in Sicily
pp. 17-21
Amblysiphonella maxima n. sp., a new species of Sphinctozoan (calcareous sponge), is described from the Upper Triassic reef limestones (Norian/Rhaetian) of the Eastern Madonie Mountains in Sicily. It is the largest species of the genus.
- Kora M., Ayyad S.N. & El Bassiouni A.E. (1988)
Biostratigraphy of some Early Tertiary outcrops from Darb El Arbain area, southern Egypt
pp. 23-31
Macro- and microfossils are utilized to study the biostratigraphic units in the southernmost Early Tertiary exposures in Egypt.
Seven biozones are described and correlated with equivalent units in other parts of the country. The Uppermost Maastrichtian and the Lowermost
Danian were not deposited in the area and many Paleocene and Eocene units were eroded. Moreover, the Globorotalia lehneri Zone is recorded here for the first time in the south Western Desert which means that the Middle Eocene sea might have covered Egypt as far south as the borders with Sudan.
- Sgarrella F. (1988)
Paleoclimatic interpretation of two deep cores from Tyrrhenian Sea
pp. 33-55
A paleoclimatic interpretation of the cores KET 8003 and KET 8019, collected in bathyal environment (Southern Tyrrhenian Sea) is given. Detailed quantitative and qualitative analyses of the benthic and planktonic foraminiferal assemblages have been accomplished. The study of the benthic foraminifers of the core KET 8019 has been done only from a qualitative point of view; in fact its lower section shows a clear contamination by shallow species. On the ground of the planktonic foraminifers percentages the paleoclimatic curves have been constructed. Taking into consideration the paleoclimatic curves, the faunistic affinites, the isotopic (δ O18) and the tephrocronologic data of the core KET 8003 (Paterne et al., 1986), the following principal climatic events have been defined: 1) the interglacial (Riss-Würm) is represented only in the core KET 8003 and is characterized by Oridorsalis umbonatus associated with a poor benthic fauna; 2) the glacial period (Würm) is characterized by an assemblage very abundant in benthic foraminifers with clear dominance of Heterolepa pseudoungeriana; 3) the postglacial: the transition last glacial-postglacial occurs at the basis showing an evident temperate-warm peak (interstadium Bølling-Allerød). In the upper part the postglacial is characterized by two warm peaks with an intermediate temperate-warm peak. The benthic microfauna of all the period is peculiarly poor.
The cited events can be correlated to those identified in the core KET 8022 (Blanc-Vernet et al., 1983). The comparison of the 3 cores points out the following conclusions: a) the different sedimentation rate which appears to be lower in the core KET 8022; b) the marked Atlantic influence occurring in the core KET 8003 testified by the notable abundance of Globigerinoides conglobatus form 1 and form 2 and the presence of Pulleniatina obliquiloculata.
The transition last glacial-postglacial is particularly evident in all the cores and it is represented by two steps: the first one (Termination 1A)
has been found in the core KET 8003 just below the E2 ash-layer (age 12.97 ± 0.18 Kyr) and in the core KET 8022 it is marked by the C2 ash-layer (age 12.3 ± 0.3 Kyr). The second step (Termination 1B) is only hypotesized in corrispondence of the interval “c” of the planktonic foraminifers.
- Surlyk F. & Dieni I. (1988)
The Sardinian connection-brachiopod Meonia semiglobularis (Posselt) links Tethyan and Boreal Maastrichtian
pp. 57-60
A rich fauna of microbrachiopods occurs in the Upper Cretaceous chalk of NW Europe. Scattered records in the literature
suggest that some elements of the fauna occur as far south as The Netherlands, Belgium and the Paris Basin. An important species, Meonia semiglobularis (Posselt), characterises the Upper Maastrichtian of NW Europe where it has its first occurrence in the top part of the Lower Maastrichtian.
It has now been found in the Lower Maastrichtian of Sardinia. This find provides an important stratigraphical link between the Tethyan and Boreal Maastrichtian.
- Azzaroli A. (1988)
On the Equid genera Dinohippus Quinn 1955 and Pliohippus Marsh 1874
pp. 61-72
Distinction between Dinohippus and Pliohippus rests mainly on characters of the skull and dentition, which are discussed in detail. Pliohippus has its latest representative in P. bakeri n. sp., from the late Hemphillian Coffee Ranch local fauna of Texas. This species differs from older representatives of the genus by its shallow facial pits.
Dinohippus is well represented in the Late Hemphillian of the central and southern U.S. by D. leidyanus and in northern Mexico by the somewhat younger, but still Hemphillian D. mexicanus. Both species were originally included in the genus Pliohippus. D. leidyanus is considered to be ancestral to Equus, possibly through the more poorly known D. mexicanus.
- Schiavinotto F. (1988)
Embryonic chambers with centripetal tendency in the Miogypsinidae from Miocene of Sardinia
pp. 73-78
Rare specimens of Miogypsina with embryonic chambers situated near the centre of the median layer occur in a sample taken from a Lower Miocene level in Sardinia. A population of Miogypsina (M.) intermedia Drooger, with an exclusively apical position of the embryonic chambers, was recently identified in the same sample by means of biometric investigations. The specimens with a centripetal tendency of the initial chambers appear referable to the subgenus Miolepidocyclina Silvestri.
This provides further evidence that many stages of the phylogeny of the Mediterranean Miogypsinidae took place in the Lower Miocene Sardinian basin. Consequently, the faunistic affinity between the Miocene neritic facies in Sardinia and the coeval basins in Aquitaine and Northern Italy is confirmed.
Specimens of Miolepidocyclina appear reworked in the sample; a wide stratigraphic gap elapsed between Miolepidocyclina and Miogypsina intermedia; this gap coincides with a long part of the time range of Miogypsina (M.) globulina (Michelotti). The presence of some reworked specimens of M. globulina in the same sample is also highly probable, with a consequent slight alteration of the previous biometric data regarding M. intermedia. Therefore, this population would be referable to a slightly more developed evolutionary stage than the one deduced from the morphometric values; nevertheless, its biostratigraphic significance appears unchanged.
- Cherchi A. & Schroeder R. (1988)
Some remarks on Paronipora Capeder, Microcodium Glück, Baccanella Pantic and Palaeomicrocodium Mamet & Roux
pp. 79-81
The Paleocene forms of the problematic microfossil Microcodium Glück 1912 of the Mediterranean area are identical with and synonyms of Paronipora penicillata, described by Capeder (1904) from the Maritime Alps. Palaeomicrocodium Mamet & Roux 1983 from Devonian is regarded as a synonym of the Triassic genus Baccanella Pantic 1971.
- Stridsberg S. (1988)
A stray cephalopod in the late Silurian of Sardinia
pp. 83-85
A single specimen of a cephalopod from the late Silurian of Sardinia, previously suggested as possibly belonging to the family Trimeroceratidae, is here transferred to the family Phragmoceratidae. It is the only known representative of this family from the Mediterranean area, and comparisons are made with species of Phragmoceras in the Baltic region and in Bohemia, Czechoslovakia.
- Masini F. & Torre D. (1988)
State variations in the dynamics of extinction and origination
pp. 89-95
The dynamics of extinction and origination is considered in order to rise some doubts on the widespread use of log-linear models, including stochastic auto-regressive models, for describing the observed variation in the data.
Three metrics of the intensity of marine familial extinction and origination during the Phanerozoic have been computed for each stage:
1 – simple number of extinctions and originations; 2 – percentage of extinctions and originations ( = number of extinctions and originations relative to standing familial diversity); 3 – percentage of extinctions and originations per MA. The frequency distributions of events have been tested for checking the goodness of fit relative to the normal model and to mixtures of two normal distributions. The analysis has been carried out by trasforming data with the natural logs. The same procedure has been followed with the residuals of regression on time in order to remove the linear time-related component. The Phanerozoic series, as well as shorter successions (the Paleozoic, minus the two latest Permian stages and the Mesozoic not including the Maastrichtian), have been considered.
Even if our results should to be accepted with caution, since the differences of significance between fitted models are sometimes small,
the bulk of analysis shows that mixed models fit better the observed variation. This evidence substantiates the hypothesis that the phenomenon was generated by a dynamic process that cannot be appropriately described by a log-linear model. This conclusion is strengthened by the
fact that log-linearity is not achieved even analyzing shorter time series, i.e. the post-Cambrian Paleozoic and the post-Triassic Mesozoic.
The results also suggest an increasing inertia of the system after the Permian crisis (greater frequency of low extinction values in the Mesozoic distributions).
The correlations between the residuals of the extinctions and originations show high values for the Jurassic-Cretaceous data, while no
significant values were obtained from the post-Cambrian Paleozoic. The regressions computed on the same data have given an analogous result. The Mesozoic strong correlation may be related to an increasing efficiency in the homeostatic control of the biotic system.
This bulk of evidence points to the possibility that the end of the Permian represents a «catastrophic» threshold dividing two different
dynamic behaviours. On the base of qualitative indications, the end of the Cretaceous may represent a catastrophic threshold too.
It is reasonable to assume that partial biotic systems, such as shelf or deep sea communities, evolved with a dynamics similar to that of the global system. Therefore detailed studies on variation in diversity of fossil communities could be a good test to the present hypothesis
and could lead to a better definition of the dynamics of the biotic systems. Actually, partial systems previde more detailed information,
and the development of the phenomena can be followed under better controlled conditions.
- Pinna G. (1988)
r and K selection and direct causes of biological crises
pp. 97-100
Considering that lands and platform areas were submitted to almost uniform environmental features during Cretaceous, it is believed that the transformation of a substantially K- into r-selective environment, occurred at the end of the period, is the proximate cause of the Late Cretaceous biological crisis.
- Vai G.B. (1988)
Evolutionism and catastrophism in a geologist’s experience
pp. 101-108
“Palaeontologists are only beginning to understand the
phenomenon of mass extinction” (Benton, 1987). If this is true, we are also only beginning to understand phyletic extinction and evolutionary processes at all. Then, the fall of approximate hypotheses can not surprise. Though being based on a few data, they have been hold
by too many specialists and amateurs as cultural dogmas instead of scientific theories.
- Pasini M. (1988)
Some views on the biological crises at the Permian-Trassic boundary in the Dolomites area
pp. 109-114
History of the research of the Italian Group concerning the Project (1981-1986) «Permo-Triassic events in Southern Alps» (supported by the Italian Ministry of Education) is briefly described.
Stratigraphical conclusions of previous Authors about the Permo-Triassic boundary in the Dolomites area maintained the Triassic Tethys transgressive on the eroded marine Upper Permian.
Geological and paleontological researches of our Group seem to prove that in this area some continuous marine fossiliferous sequences between the Uppermost Permian and the Lowermost Triassic are available and it is possible to observe the behaviour of different « taxa » in connection to the P/T boundary.
Two patterns concerning the behaviour of the number of genera of foraminifers are relate for the P/T boundary of two sequences outcropping at Tesero (Val di Fiemme) and at Passo Zovo (Cadore). The first shows a gradual fail from 20 to 11, 10, 6, 4, 0 genera; whereas the second shows a strong break from 30 to 8, 6, 5 genera; but the value O is missing.
At present our paleontological researches confirm a quick extinction of many (but not of all) permian foraminifers and Invertebrates. However the highest fail in the number of genera (and species) of some «phyla» is not in connection to the P/T boundary. F. ex. for the Fusulinids this fail occurs between the Middle and the Upper Permian. In addition geochemical data do not confirm the presence in the Southern Alps of a peak of Iridium at the P/T boundary.
Our present idea on the P/T biological crisis is that it is probably due to coincidence of different chimico-fisical causes rather than to a «cosmic sudden event».
The results of the researches of the Italian Group have been shown during the Field Conference on the« Permian-Triassic boundary in the South Alpine segment of the Western Tethys » (Chairman Prof. G. Cassinis, I.G.C. Project n. 203, 4-12 July 1986, Brescia (Italy)).
- Minelli G. (1988)
Alcune osservazioni sull’evoluzione
pp. 115-118
The mechanisms of evolution are critically examined by comparing the hypothesis of a gradual process with evolution by steps; examples interpretable by either evolutionary mechanism are presented. The two hypotheses also differ in the way they are realized: gradual evolution is, in fact, understandable with the classical neo-Darwin theory, which sees graduai mutation in the germinal line as the only evolutionary vehicle, while the hypothesis of evolution by sudden jumps followed by more or less long intervals without any evolution, is stili interpretable through mutation phenomena of a casual, but possible nature even in the somatic line where they would be selected and rewarded (hypothesis of evolution on somatic selection). The transfert of these mutants would be realized through viruses of the retrovirus type, whose ability to transfer genes even between different species of organisms as well as within the compass of the same species or between tissues of the same individuai, is already known.
- Bartolini C. (1988)
Astronomical events producing biological crises
pp. 119-121
Several extraterrestrial phenomena have been invoked for explaining the mass extinctions occurred in the past. The impact on the Earth of comet showers have been proposed to account for the periodicity of 26 million years found in the percentages of extinction. Two mechanisms could drive toward the innerst part of the solar system many comets of the Oort cloud: an unseen companion to the sun (Nemesis) travelling in an eccentric orbit, and the sun’s oscillation perpendicular to the galactic plane.
According to the astronomical theory of paleoclimates, the long-term variations in the geometry of the Earth’s orbit are the fondamental cause of the succession of Pleistocene ice ages.
Non-periodic events are supernova explosions not far from the sun and impacts of large asteroids on the Earth. Among the reviewed causes the hypothesis of Nemesis can be ruled out.
Issue 2
Published in September 1988
- Delle Cave L. (1988)
Monodaeus bortolottii, a new species of Brachyura (Crustacea, Decapoda) from the Pliocene of Tuscany (Italy)
pp. 123-127
A new species of Brachyura, of Piacenzian age, is described from Tuscany. The finding is remarkable because the chelae of the first pereiopods are partially preserved, the features of which are important for the diagnosis. The specimen attributed to the genus Monodaeus with some doubt, shows some similarities also with Haydnella steiningeri Muller, 1984, species from the Badenian of Austria.
- Conti S. & Serpagli E. (1988)
Bimineralic (calcareous and phosphatic) skeleton in Late Ordovician Bryozoa from Sardinia: Geological implications
pp. 129-162
The study of Palaeozoic Bryozoa from the Upper Ordovician of Sardinia was carried out by integrating the traditional thin section description with the SEM observation of single zooecia or zoarial remnants, isolated by acid acetic technique. This technique was made possible by the presence of a bimineralic (calcareous and phosphatic) skeleton, which is interpreted as the result of the primary mineralization of the membranous part of the cryptocyst originally very rich in phosphorus. The frequent records of phosphatic bodies in Bryozoa lead us to hypothesize the possibility that some Bryozoa secreted, at least in the Palaeozoic, a phosphatic skeleton in response to particular environmental conditions. The deposition of calcium phosphate occurred in the zooecial cavity owing to the change in chemical conditions between the regeneration and degeneration phases.
- Biffi U. & Manum S.B. (1988)
Late Eocene-Early Miocene dinoflagellate cyst stratigraphy from the Marche Region (Central Italy)
pp. 163-212
The dinoflagellate cyst stratigraphy of four sections across the Paleogene-Neogene boundary in the Marche Region, Central Italy, is described. These stratigraphic boundary sections have previously been studied intensively with regard to planktonic foraminifera and nannoplankton, however, with somewhat equivocal results regarding boundary definitions. Seven dinoflagellate zones and six sub-zones spanning the Late Eocene-Early Miocene have been defined and calibrated to Standard Nannoplankton Zones NP19 through NN4. This zonation helps to clarify some boundary ambiguities left by the other microfossil studies. The following new species of dinoflagellate cysts are described: Caligodinium pychnum, Hystrichokolpoma pusilla, H. truncata, Membranilarnacia (?) picena, Stoveracysta conerae, Systematophora urbinii, Cerebrocysta mediterranea, Impagidinium tectum, I. minor, I. eugubinum, Leptodinium italicum, Pyxidinopsis elliptica. Based on a detailed study of Caligodinium pychnum n. sp. a new interpretation for the epicystal paratabulation and apical archeopyle in Caligodinium Drugg and its type species C. amiculum is presented.
- Rio D., Sprovieri R., Raffi I. & Valleri G. (1988)
Biostratigraphy and paleoecology of the Piacentian stratotype section
pp. 213-238
A detailed paleoecological (qualitative and quantitative multivariated) and biostratigraphic (foraminifera and calcareous nannoplankton) analysis of 44 large samples collected along the sequence outcropping on the left side of the Arda valley between the Lugagnano and Castell’Arquato villages, including the Piacenzian stratotype section (Barbieri, 1967a), pointed out that:
1) About 20 meters above the base of the sequence outcropping at Monte Giogo an hard, arenitic level, about 20 centimeters thick, with
glauconite and locally bioeroded by molluscs, outcrops. A sharp paleoenvironmental change can be documented between the sediments just below and the sediments iust above this arenitic level. This sharp paleoecological change makes it possible to clearly identify the base of the Piacenzian stratotype section (Barbieri, 1967a). The sedimentary sequence represented in the Piacenzian stratotype section can be referred to an epineritic environment (70-100 meters in depth), with scarse bottom vegetation in the lower part, which is more abundant in the upper part. To a quite normally oxigenated bottom environment in the lower part of the section, a partially generalized dioxic bottom environment follows upwards, where two well detectable short peaks with strong dioxic environment can be recognized. Coincident with these peaks a sharp decrease in species and specimens number of the benthic foraminifera is detectable.
2) In the Vernasca-Castell’Arquato sequence, coincident with the base of the Piacenzian stratotype section, a stratigraphic gap is present. It covers all the M Pl 3 biozone and probably the uppermost part of M Pl 2 and the lowermost part of M Pl 4 biozones. According to the calcareous nannoplankton biostratigraphy all the C. rugosus, the upper part of the Amaurolithus tricorniculatus and the lowermost part of the R. pseudoumbilica biozones (Raffi & Rio, 1979, emended) are missing. The time interval involved is about 0.8 MA, between about 4.3 and 3.5 MA. Owing to this stratigraphic gap the local disappearance of Gt. margaritae is not coincident with the mediterranean LAD (Last Appearance Datum) of this species. The basal sediments of the Piacenzian stratotype section postdate the LAD of Gt. margaritae and predate the LAD of Gt. puncticulata.
In terms of nannoplankton biostratigraphy they are practicalty coincident with the base of the D. tamalis biowne of Raffi & Rio (1979). According to biochronologic evaluation, it can be dated between 3.6 and 3.4-3.3 MA.
3) In all the Piacenzian stratotype section, even in the uppermost part, Gt. inflata is missing. The occurrence of Gt. bononiensis and Gt.
crassaformis s.l. and of D. surculus makes it possibile to refer the uppermost levels to the foraminiferal M PI 5 biozone, excluding the Gt. inflata biozone. According to the foraminiferal assemblage and the calcareous nannoplankton distribution, the top of the Piacenzian stratotype can be referred to an absolute age of about 2.4 MA. Therefore the coincidence of the top of the Piacenzian, as defined in its stratotype section, with the N/Q boundary as defined in the Vrica section, cannot be maintained: a time lag of about O.7-0.8 MA, between 2.4 and 1.67 MA, exists between the two chronostratigraphic boundaries.
4) The Piacenzian stratotype section can be referred to the M Pl 4 (pars) and to the M Pl 5 (pars) foraminiferal biozones and to the D. tamalis and D. pentaradiatus (excluding its uppermost part) nannoplankton biownes.
5) The top of the Piacenzian, as chronologicalty evaluated, slightly predates the onset of the « Glacial Pliocene ».
6) A new chronostratigraphic unit must be introduced to indicate the long time interval between the top of the Piacenzian and the base of
the Pleistocene. As a consequence, a tripartition of the Pliocene would result: it would have, nevertheless, conceptual and practical meaning very different from the tripartition now adopted by some italian Authors.
- Ruggieri G. (1988)
Representatives of the genus Basslerites (Ostracoda, Podocopida) in the Mediterranean Miocene
pp. 239-243
Representatives of the genus Basslerites are firstly recorded from the Mediterranean Miocene. The two species collected are described as new, B. canavarii and B. quadriforatus. They show interesting affinities with the subgenus Loculiconcha, living today along the Western coast of the Equatorial Africa.
- Bernhardt B., Landini W. & Varola A. (1988)
Georadar and its use to Paleontology
pp. 245-251
There is the description of a new method of paleontological research based on the application of georadar.
The technical characteristics of the instrument are illustrated together with the results of tests carried out in 1986 on the Lecce rock, which
contains many remains of marine vertebrates, and on argillaceous sediments of the Rotonda fluvial-lacustrine basin (Potenza), in which the remains of terrestrial vertebrates have been found.
- Borselli V., Ficcarelli G., Landucci F., Magnatti M., Napoleone G. & Pambianchi G. (1988)
Report of Pleistocene Mammals of Colfiorito (Umbro-Marchean Apennines) and evaluation of the deposit capacity by georadar prospecting technique
pp. 253-257
Preliminary data on the existence of a fossiliferous mammalian deposit in the Pleistocene lacustrine sediments at Colfiorito, Marche, are reported. Its location and the evaluation of its extention have been accomplished by means of a specifically planned geophysical survey using the georadar prospecting technique. Several areas, in the order of 500 sq. meters, have been mapped, and the resolution power in identifying individual fossil finds has reached the size for recognizing pieces as large as a hippopotamus vertebra. Fossil material has been recovered at only one site and the results have been extremely satisfactory.
The paleontological deposit has yielded an assemblage of Hippopotamus antiquuus, Dicerorhinus etruscus, Elephas sp., two cervidis species, an equid, a quite evolved bovid and a hyenid. Their occurrence suggests an age comprised between the uppermost Early Pleistocene and the lowermost Mid Pleistocene. From the palaeoecological point of view, the assemblage seems to belong to a moist and open forest environment.
Issue 3
Published in December 1988
- Burgio E. & Fiore M. (1988)
Nesolutra trinacriae n. sp., a Quaternary otter of Sicily
pp. 259-275
The Authors describe a new species of lutrine, found in the Poggio Schinaldo cave (Sicily) associated with an interesting vertebrate fauna. This new species of lutrine has been compared to the present day Lutra lutra and to the Mediterranean Pleistocene fossil forms, Nesolutra ichnusae and Nesolutra euxena; the genus Nesolutra was founded on some limb bones, the only remains so far known of the type species Nesolutra euxena. Numerous characteristics of various anatomic parts (skull, humerus, tibia) allowed the introduction of a new species: Nesolutra trinacriae.
Diagnosis: middle size lutrine between Lutra lutra and Nesolutra ichnusae; the skull is squat and broad with a flat dorsal surface parallel to the ventral one; muzzle cut off by big nasal fossae; short post-orbital process and strong, high zygomatic arcs with a marked post-orbital constriction; swollen brain-case with very broad foramen magnum; the tympanic bullae are elongated and triangular in shape.
Dental formula: 3⋅1⋅4⋅1 / 3⋅1⋅3⋅2
The post-cranial skeleton shows some peculiar characteristics which indicated a more advanced specialization as compared with L. lutra.
Specifically the humerus is more squat and markedly curved dorso-ventrally with a very large epicondyle crest. The radius is characterized by a very curved diaphysis, large distal epiphysis and strong muscular insertion rugosities. The tibia has an elongated diaphysis, a very prominent and laterally curved tibial crest and sharp and well developed fossae for the muscular insertions.
The analysis of the associated fauna ascribed N. trinacriae to the middle-upper Pleistocene.
- Colalongo M.L. & Pasini G. (1988)
Bathyal Plio-Pleistocene ostracofauna from ODP Leg 107, Hole 654A (Western Tyrrhenian Sea)
pp. 277-289
Bathyal benthic ostracodes from the Plio-Pleistocene interval of ODP Leg 107, Hole 654A (Western Tyrrhenian Sea) were studied. In the 106 samples examined 40 autochthonous species were recognized, two of which (Krithe padovanii and K. martinssoni) are erected in this paper as new species. The stratigraphic ranges of the ostracodes of Hole 654A were related to the calcareous plankton biostratigraphy of this hole: this permitted to outline or to confirm — at least as regards the Western Mediterranean — the stratigraphic significance of several bathyal ostracodes scantily studied up to now. The extinction levels of Agrenocythere pliocenica (a psychrospheric ostracode) in Hole 654A and in some Italian land sections indicate that the removal of psychrospheric conditions took place in the Mediterranean Sea during or after the time interval corresponding to the Small Gephyrocapsa Zone (Upper part of early Pleistocene), and not at the beginning of the Quaternary, as previously stated.
- Sarti C. (1988)
Two new species of Idoceratinae (Ammonoidea) in the Kimmeridgian of the Venetian Prealps (Northern Italy)
pp. 291-299
Nebrodites ferrarii and Mesosimoceras cristinae are two new species of Idoceratinae discovered in the basal upper part of the Rosso Ammonitico
Veronese formation of the Venetian Prealps. The biostratigraphical extension of Nebrodites ferrarii is limited to the middle and upper part of the Acanthicum Zone within the Kimmeridgian (in the Southern European sense) and the extension of Mesosimoceras cristinae is limited to the Strombecki and Divisum Zone within the Kimmeridgian (S.E. sense). Notwithstanding the ornamentation clearly belongs to Nebrodites and approaches
the agrigentinus–doublieri species-group, the new species shows a spire increase comparable with that of Mesosimoceras species-group cavouri–risgoviense. For this reason and for its stratigraphic intermediate position one could consider this species as a passage form to this last group, starting from the Nebrodites of the agrigentinus–doublieri species-group. The new species M. cristinae, owing to its ornamentation with simple ribs ending in a margine-ventral knot, subquadrangolar spires and type of increasing, belongs to the genus Mesosimoceras.
- Salvadori A. (1988)
Intratalamic schizogony example in a eocenic form of Orbitolites
pp. 301-305
Micropaleontologic investigations regarding the lower Eocene in the Sulcis basin (SW Sardinia) has brought to light forms of Orbitolites fossilized during the asexual phase of the reproductive cycle; their characteristics are described and some photos reproduced.
- Ciampo G. (1988)
New Pliocenic Ostracoda species from Ionic Calabria
pp. 307-321
Fifteen new species of Pliocenic Ostracoda from Calabria (Southern Italy) are described, they are:
Callistocythere geracensis — a pitted species with a developed posterior ridge. Range: from Gt. margaritae/Gt. puncticulata Zone to Globigerinoides elongatus Zone.
Callistocythere mutabilis — a very finely pitted species. Range: from Gt. margaritae Zone to Sphaeroidinellopsis subdehiscens Zone.
Cytheropteron aemulum — a smooth species with an enlarged wing. Range: from Gt. margaritae/Gt. puncticulata Zone to Sph. subdehiscens Zone.
Cytheropteron (Aversovalva) amplum — a smooth, pitted species, with a rounded outline in dorsal view. Range: from Gt. margaritae/Gt.
puncticulata Zone to Sph. subdehiscens Zone.
Cytheropteron argutum — a species with a smooth anterior area and a coarsly pitted posterior one. Range: from Gt. margaritae Zone to
Gt. margaritae/Gt. puncticulata Zone.
Cytheropteron ridendum — a rough species with an high, conical, irregular alar prolungation. Range: from Gt. margaritae/Gt. puncticulata
Zone to Sph. subdehiscens Zone.
Eucytherura calabrica — an irregularly reticulated species. Range: Sph. subdehiscens Zone.
Loxocoricha atra — a smooth species, pitted by rounded normal-pores. Range: from the top of Gt. margaritae/Gt. puncticulata Zone to Sph.
subdehiscens Zone.
Loxoconcha imparilis —a species with an inflated posterior part and numerous large sieve-types normal pore-canals. Range: from Gt. margaritae to Gt. margaritae/Gt. puncticulata Zone.
Nonurocythereis robusta — a kidney shaped species, lightly pitted. Range: from Gt. margaritae/Gt. puncticulata Zone to Sph. subdehiscens Zone.
Rectotrachyleberis elegans — a pitted species with a broadly rounded anterior margin. Range: from Gt. margaritae/Gt. puncticulata Zone to Gld. elongatus Zone.
Saida ionia — a deeply pitted species, oval shaped in lateral view. Range: from Gt. margaritae/Gt. puncticulata Zone to Sph. subdehiscens Zone.
Semicytherura angelica — a species with a central S shaped ridge and covered by a fine reticulation. Range: from Gt. margaritae/Gt. puncticulata Zone to Sph. subdehiscens Zone.
Semicytherura scabra — species with relatively high longitudinal ridges and irregularly reticulated. Range: from Gt. margaritae/Gt. puncticulata Zone to Sph. subdehiscens Zone.
Semicytherura variabilis — species with low alar swelling and covered by light reticulation. Range: from Gt. margaritae/Gt. puncticulata
Zone to Sph. subdehiscens Zone.
- Gnoli M., Leone F., Olivieri R. & Serpagli E. (1988)
The Mason Porcus Section as reference section for Uppermost Silurian-Lower Devonian in SW Sardinia
pp. 323-334
The lithology and paleontological content of biostratigraphical interest, mainly conodonts, of one of the more representative Upper Silurian-Lower Devonian sequences cropping out in Southwestern Sardinia are described. The conodont data permit for the first time establishment of the approximate level of the Silurian/Devonian boundary in this part of the region.
- Brönnimann P., Whittaker J.E. & Parisi G. (1988)
Prosphaeroidinella Ujiié in the Lower Pliocene of southern Tuscany, Central Italy, with remarks on wall structure and taxonomy of the Sphaeroidinellinae
pp. 335-348
The basic planktonic assemblages encountered in the MPI 3 zone of the Radicofani Basin, southern Tuscany, central Italy, are suggestive of a cold to temperate water environment. However in a few samples warm water taxa, such as Prosphaeroidinella, Sphaeroidinellopsis and Sphaeroidinella, occur.
The walls of the final chambers of broken specimens of P. parkerae show 2 layers, the inner thin subiculum, and the outer thick laminarium,
and those of S. seminulina 3 layers, the inner thin subiculum, the middle thick laminarium and the outer thick hyalinarium. The thin cortex sensu Blow is not always present and it represents possibly a formation foreign to the foraminifer.
On the basis of the analyses of the wall structure, the subfamily Sphaeroidinellinae Banner & Blow 1959 and the genera Prosphaeroidinella
Ujiié 1976, Sphaeroidinellopsis Banner & Blow 1959, and Sphaeroidinella Cushman 1927 are re-defined.
The new species Prosphaeroidinella valleriae apparently evolved from P. disjuncta (Finlay) and is ancestral to Sphaeroidinellopsis seminulina.
- Bonaduce G., Ruggieri G. & Russo A. (1988)
New Ostracode genera of the Mediterranean Miocene
pp. 349-360
The study of Miocene marine Ostracoda, mainly from Sicily allowed the erection of 4 new genera, namely: Capsacythere (type-species: Falunia sicula Aruta), Tegmenia (type-species: Cytherina rugosa Costa), Heliocythere (type-species: Hemicythere magnei Keij), Dallonella (type-species: Dallonella speciosa n.sp.). The genus Heliocythere is also represented in extra-Mediterranean Miocene, the genus Tegmenia survives into the Mediterranean Pliocene.
- Bosellini F.R., Luciani V., Russo A. & Sirotti A. (1988)
New data on the Palaeogene stratigraphy of the Monte Baldo, Southern Alps, Italy
pp. 361-366
The Monte delle Erbe Limesto- ne, formally defined as an Early Oligocene formation of the Monte Baldo area, and considered laterally equivalent to the Acquenere Formation, is in fact of Late Eocene (Priabonian) age. It is therefore equivalent to the Nago Limestone and stratigraphically underlying the Early Oligocene succession which is constituted by a lower pelagic unit (Bolognano Marls) and an upper shallow-water terrigenous-carbonate sequence, the Acquenere Formation proper.
- Van der Made J. (1988)
Sus nanus nov. sp., a Pliocene dwarf pig from Capo Figari (Northeastern Sardinia)
pp. 367-378
Sus nanus n.sp. from the fissure fillings of Capo Figari (NE Sardinia) is an endemic island species. Its most probable ancestor is Sus arvernensis. Evolutionary changes in this lineage are: reduction in the size of the dentition and in the size of the body, reduction in the size and number of the anterior premolars, increase in the crown height of the molars, the last premolar and I1 and earlier loss of the milk dentition. The increased crown height may be explained as an adaptation to harder food, which indicates a change in the environment, most probably towards a drier climate.
If Sus arvernensis is the ancestor of Sus nanus the Capo Figari fauna must be MN 14 (early Ruscinian, Early Pliocene) or younger.
- Cherchi A. & Schroeder R. (1988)
Le «microcells» dello scheletro di Pseudomillestroma reticulata Deng 1982 (Demospongiae) del Cretaceo inferiore del Tibet
pp. 379-382
Le «microcells» presenti nello scheletro di Pseudomillestroma reticulata Deng 1982, del Cretaceo inferiore del Tibet, vengono interpretate come microsclere reniformi. La struttura scheletrica di questa specie mostra delle affinita con quella di certe Demospongiae (Rhaxella, Geodia) e con quella di una spugna appartenente alla stessa classe ma dalla posizione sistematica ancora incerta, del Permiano inferiore di Djebel
Tebaga (Tunisia), descritta da Termier et al. (1975).