Bollettino SPI Vol. 57 (2)

Published in September 2018


  • Mazza M., Nicora A. & Rigo M. (2018)

Metapolygnathus parvus Kozur, 1972 (Conodonta): a potential primary marker for the Norian GSSP (Upper Triassic)
pp. 81-101


The base of the Norian Stage (Carnian/Norian boundary, Upper Triassic) is still awaiting a formal designation by the International Commission on Stratigraphy. At present, two stratigraphic sections, Pizzo Mondello (Sicily, Italy) and Black Bear Ridge (British Columbia, Canada), have been proposed as GSSP (Global Stratotype Section and Point) candidates for the base of the Norian, but a bio- or physical primary marker event has not been yet selected by the Working Groups. We show here that conodonts represent the best choice to define the Carnian/Norian boundary. In the Upper Triassic, in fact, conodonts have been studied in great detail in the last 15 years providing a very high resolution biostratigraphic tool. We illustrate here the phylogenetic lineage Metapolygnathus praecommunisti - Metapolygnathus dylani - Metapolygnathus parvus, demonstrating that this lineage is present in both the GSSP candidate sections. Thus, we propose the First Occurrence (FO) of Metapolygnathus parvus (the last representative of its lineage) as a potential primary marker to define the base of the Norian Stage. Metapolygnathus parvus is in fact the most reliable and useful biomarker, because this species is morphologically simple and easy to recognise and its First Appearance Datum (FAD) is globally recognisable within its phylogenetic lineage. The FO of M. parvus also coincides with an important global conodont faunal turnover (known as T2), that corresponds to the disappearance of the typically Carnian conodont genus Carnepigondolella and the rise of the genus Metapolygnathus. In addition, the FO of M. parvus occurs very close to a brief positive δ13Ccarb shift, documented in the two GSSP candidate sections and in the uppermost part of the magnetozone PM4n (ca. at 3.20 m below the top) at Pizzo Mondello.

  • Falzoni F., Petrizzo M.R. & Valagussa M. (2018)

A morphometric methodology to assess planktonic foraminiferal response
to environmental perturbations: the case study of Oceanic Anoxic Event 2,
Late Cretaceous
pp. 103-124


Dwarfism of planktonic foraminiferal specimens is recognised across several intervals subject to globally extended environmental disturbances such as the Cretaceous/Palaeogene boundary and the latest Cenomanian-earliest Turonian Oceanic Anoxic Event 2 (OAE 2) in the Late Cretaceous. However, the occurrence of dwarfed specimens is generally based on the observation of a decrease in the size of specimens at the stereomicroscope without acquiring morphometric data. This approach prevents from assessing the inter-sample morphometric variation of species, reconstructing species-specific trends, and comparing data from different localities to extrapolate global from local signals. We present herein a first step toward the development of a morphometry-based methodology to assess planktonic foraminiferal response to past environmental perturbations. To perform this study, we selected OAE 2 as a target event and we focused on two species, Rotalipora cushmani (Morrow, 1934) and Whiteinella brittonensis (Loeblich & Tappan, 1961), commonly occurring in the assemblages and likely having different palaeoecological preferences. Specimens analysed are from Eastbourne (England), Clot Chevalier (SE France), and Tarfaya (core S57, Morocco). For both species, we measured selected shell parameters (i.e., the number of chambers in the last whorl, the maximum diameter and the height of the test). Our study suggests that the maximum diameter across the first chamber of the inner whorl visible in spiral view is the simplest and most objective methodology to estimate shell size variation in trochospiral planktonic foraminifera, and that this morphometric parameter is likely the most sensitive to the Cenomanian-Turonian environmental disturbances, and thus its variability through time appears worth investigating across other key-stratigraphic intervals. Moreover, this study indicates that the acquisition of morphometric data is required to accurately reconstruct planktonic foraminiferal response to environmental perturbations, because specimen dimensions show high inter-sample variability and based on the data collected in this study they do not experience the predicted size reduction.

Supplementary Online Material
  • Jukar A.M., Sun B. & Bernor B.L. (2018)

The first occurrence of Plesiohipparion huangheense (Qiu, Huang & Guo,
1987) (Equidae, Hipparionini) from the late Pliocene of India
pp. 125-132


Hipparionine horses are well known from the Miocene of the Indian subcontinent and include several lineages. Their Pliocene record is poorly known in comparison. Here we report the first record of a hipparionine horse lineage, Plesiohipparion huangheense, from late Pliocene sediments in the Siwalik Hills in N.W. India. This species was formerly known from the late Pliocene of Northern China and the earliest Pleistocene of Turkey. This new occurrence presents us with two dispersal hypotheses for this species. By analyzing faunal connections across Eurasia, we conclude that P. huangheense most likely dispersed from China to India and Turkey from north of the Tibetan Plateau.

  • Rosso A., Sanfilippo R., Bonfiglio L., Richards D.A. & Nita D.N. (2018)

Exceptional Pleistocene vermetid crusts preserved in a cave
located 130 m above sea level near Taormina (NE Sicily)
pp. 133-144


Wide coastal sectors of north-eastern Sicily are shaped by high rates of tectonic Pleistocene uplift of the area and concurrent glacio-eustatic sea level changes leading to the formation of terraces, characterised by basal marine sediments topped by continental vertebrate- bearing sediments, and caves with evidence of marine submersion. A tidal notch and associated organogenic crusts, formed by the vermetid gastropod Dendropoma cristatum found in a cave near Taormina located at an elevation of 130 m a.s.l. just above the terrace produced during the Tyrrhenian (MIS 5.5), were examined. This represents the first record of extensive vermetid bioconstructions inside a cave and a particular morphology of D. cristatum shells, which include coiled initial parts and straight distal elongated parts, with numerous internal septa. These specimens were preserved in a restricted area, with extended portions aligned parallel to each other and facing downward from a sub-horizontal step along a wall. The location of the vermetid crusts and the particular ecological requirements of this species (presently forming bioconstructions in exposed rocky shores characterised by high light intensity and water energy) points to a cave which was semi-submerged and widely open to the water energy at the time of its colonisation. The particular Dendropoma shell morphology has been interpreted as an adaptation to reach penetrating water flow rich in food and oxygen, also seen in other organisms from cave habitats. Apparent ages of the Dendropoma shells and the continental calcite crust obtained with the U-Th dating method are not consistent with the stratigraphic position of the cave and are significantly younger than expected. As observed for other dating results on the same species (and other molluscs), this indicates an alteration of the system during diagenesis and suggests caution in the use of certain species as stratigraphic constraints.

  • Carrera L., Pavia M., Peresani M. & Romandini M. (2018)

Late Pleistocene fossil birds from Buso Doppio del Broion Cave (North-Eastern Italy): implications for palaeoecology, palaeoenvironment and palaeoclimate
pp. 145-174


The taxonomic and taphonomic analysis of the bird fossil remains from Buso Doppio del Broion Cave (Vicenza), located in the Berici Hills in North-Eastern Italy, are presented herein. The investigated deposits are referred to the end of MIS 3 and the boundary with MIS 2, in a phase of climate harshening. At least 44 species have been identified in the study, which indicate the presence of a wide variety of environments in the surroundings of the cave, such as conifer or mixed forests, open areas with rocky cliffs or crags, grasslands, steppes and slow flowing water bodies. Of particular interest are two Boreal taxa, Bubo scandiacus and Surnia ulula, which are considered markers of a colder climate than the present one. The S. ulula specimen represents the second Pleistocene fossil record of this species in Italy, attesting the presence of this taxon across the MIS 3/MIS 2 boundary, at least in the southern fringes of the Alps. Furthermore, the deposit provided the first Italian Pleistocene fossil remains of Troglodytes troglodytes and Phoenicurus ochruros. This contribution provides noteworthy new data about the southward range shift of Boreal bird species during the cold phases of the Pleistocene and gives new insights into the palaeoenvironment and palaeoclimate of North-Eastern Italy at the end of MIS 3 and the onset of the Last Glacial Maximum.