Bollettino SPI: Vol. 50 (2) 2011

Perleidus sinensis n. sp., a new species of “Subholostean” fossil fish of the order Perleidiformes is described herein on the basis of a single, well-preserved specimen collected from the Upper Member of the Guanling Formation (Pelsonian, Middle Anisian, Middle Triassic) outcropping near Luoping (Yunnan Province) in South China. The vertebrate assemblage yielded by these levels is proving to be of importance with regard to the marine Triassic ichthyofaunas, not only due to the variety, richness and quality of preservation of the faunas, but also from a paleobiogeographic point of view. The new taxon here described belongs to the genus Perleidus, so far represented only in the upper Ladinian of Northern Italy and Switzerland; this find reconfirms a very close connection between the Eastern and Western Tethys during the Middle Triassic, when many fish genera may have migrated from the Southern China Block to the Western Tethys area, giving rise to a notable radiation during some intervals of the Triassic. Besides Perleidus, other actinopterygians are common to both margins of the Tethys, such as Sangiorgioichthys, Habroichthys, Placopleurus, Peltopleurus, Peltoperleidus, Marcopoloichthys, Colobodus, Luopingichthys as well as the cosmopolitan genera Saurichthys and Birgeria.

A new genus and species of delthyridoid spirifer brachiopods, Lusitanispirifer lusitanensis, is established in the present study. The taxon is described from the Dornes Formation within the Dornes Syncline (Central Portugal) and based on the associated fauna a Siegenian to Emsian (middle to late Early Devonian) age is indicated. [Remark: Neritic Gedinnian strata represent the pelagic Lochkovian strata, neritic Siegenian strata represent approximately pelagic Pragian strata]. Due to its capillate micro-ornamentation the new genus is attributed to the northern Gondwana delthyridoid spirifer fauna, however, it also shows similarities to the genus Australospirifer from the Malvinokaffric Realm. The relationship of Lusitanispirifer with the other genera within the capillate family Filispiriferidae to which it has been assigned, and Australospirifer is discussed. Implications derived from this study are put forward regarding the palaeogeographic position of the Dornes Syncline area during the Early Devonian.

A large complete wall of the whale barnacle Coronula diadema (Linnaeus, 1767) occurring in early Pleistocene (Calabrian) mudstones near Riparbella (Tuscany, Italy) is described. Sedimentary facies analysis indicates that these deposits represent an open shelf setting, similar to many of those reported for whale fossils to date. The extant and fossil record of C. diadema and other species belonging to the genus and family are revised herein. The study confirms a global distribution for C. diadema and dates its presence in the Mediterranean from the early Pleistocene (Calabrian). A global distribution is attributed to the only other well-known fossil coronulid, Coronula bifida Bronn, 1831, which is common within the Pliocene record of the Mediterranean, and is documented in the Pliocene of the Pacific domain and in the earliest Pleistocene of the Atlantic [as C. barbara (Darwin, 1854)]. No overlap of stratigraphic ranges has been noted: C. bifida occurs in the Piacenzian-Gelasian and C. diadema is recorded from the Calabrian to the present. It is therefore suggested herein that C. diadema is a direct descendant of C. bifida and that the evolution of the former included a pronounced increase in size of the adult shell. The fossil record of large whales supports this hypothesis, which is further reinforced by the global character of its hosts such as the ocean-going humpback, blue, fin, and sperm whales. The general high host specificity of whale barnacles, which today include Cetopirus complanatus (Mörch, 1853) of the same family, can be extended back to the Pliocene. Considering these aspects, a coevolutionary trend towards an increase in size linking oceanic whales with coronulids is proposed.

Findings of small vertebrate remains are presented from three different localities of the Baccano maar area (Sabatini Volcanic District, Rome, central Italy), referred to as Baccano 1, Baccano 2 and Baccano 3 respectively. The first vertebrate assemblage (Baccano 1) occurs in palustrine sediments containing lignites in the southern part of the Baccano maar and contains a rich fauna of non-marine molluscs: Bithynia tentaculata, Stagnicola palustris, Galba truncatula, Planorbis planorbis, Acroloxus lacustris, Succinea sp. and Sphaerium sp. The small vertebrate assemblage from this site is composed of the following taxa: “Pisces” indet., Triturus carnifex, Pelophylax bergeri or Pelophylax klepton hispanicus, Rana dalmatina, Podarcis sp., Aves indet., Crocidura sp., Myodes glareolus, Microtus (Terricola) savii, Arvicola amphibius and Apodemus sylvaticus. The second assemblage (Baccano 2) occurs in strata of reworked pyroclastic deposits in the western-northwestern part of the Baccano maar area and includes the following taxa: M. glareolus, Microtus (M.) arvalis, M. (T.) savii, A. amphibius and Apodemus sp. The third assemblage (Baccano 3) occurs in the same area, however, within an alluvial deposit and comprises the following taxa: Sorex minutus, S. antinorii, S. samniticus, M. (M.) arvalis and Chionomys nivalis. The Baccano 1 assemblage is assigned in age to the early part of the MIS3, the Baccano 2 assemblage to the most recent part of the MIS3 or the beginning of MIS2 while the Baccano 3 assemblage is attributed to the last pleniglacial (MIS2).

Quantitative and semiquantitative analyses carried out on calcareous (foraminifers, ostracods, calcareous nannofossils = CN) and siliceous (diatoms, radiolarians) microfossil associations preserved in diatomaceous silts and clays from Monferrato (Piedmont, Northwestern Italy), forming part of the Argille Azzurre (Blue Clay) Formation, document episodes of enhanced productivity during the Early Pliocene (Zanclean). This study represents the first documentation in Piedmont of Pliocene mixed calcareous and siliceous microfossil assemblages, generally reported from areas of upwelling and high productivity conditions. The assemblages collected from the sections of La Torretta, Castelcebro and Calliano allow a nearly coincident time interval to be proposed for their deposition, in the MPl 3 foraminiferal Zone (Globorotalia margaritae - Globorotalia puncticulata Zone), the MNN13 and/or MNN14-15 CN zones, the Nitzschia jouseae diatom Zone and RN11 (Stichocorys peregrina Zone) radiolarian Zone. High productivity in the water column is documented by the following: the frequent occurrence of diatoms, dominated by Chaetoceros RS, Thalassionema group and locally by Paralia sulcata, all related to upwelling conditions; the common to frequent presence of radiolarian; opportunistic phytophagous or dominantly phytophagous cool-water planktonic foraminifers (Globigerina bulloides, Neogloboquadrina acostaensis, Globigerinita glutinata and Turborotalita quinqueloba); benthic infaunal taxa, phytodetritus feeders or exploiting different trophic resources (Cassidulina carinata, Bulimina spp., Stainforthia complanata); the common ostracod Costa edwarsii and also by common Calcidiscus leptoporus, Helicosphaera carteri and H. sellii, also related to mesotrophic to eutrophic cool waters. The absence of the oligotrophic discoasterids may be another signal of high nutrient levels. Productivity was rather high in comparison with that suggested for coeval assemblages in Piedmont, devoid of siliceous microfossils and generally characterized by more diversified foraminiferal and ostracod assemblages. Nevertheless, the rather low diatom numbers suggest a moderate productivity in comparison with recent oceanic upwelling areas. The low Foraminiferal Number (FN) and benthic foraminifer and ostracod diversity may result from dilution of tests in the generally very abundant fine-grained terrigenous fraction, but could be influenced also by seasonal upwelling conditions. Similar very low FN characterized the MPl 3 assemblages in the deeper, epibathyal succession of Moncucco Torinese and suggest an increase of deposition rate, due to the warm, moist Early Pliocene climate. Seasonal successions of cool eutrophic (G. bulloides, N. acostaensis, T. quinqueloba) and warm oligotrophic taxa (Globigerinoides spp., Orbulina spp.) are suggested in the upper La Torretta section by their contemporary common occurrence.

A short account is presented here of the discovery of new material attributable to Paralutra garganensis Willemsen, 1983, the only carnivore species documented from the Late Miocene endemic “Terre Rosse” faunal complex (also referred to as the “Mikrotia fauna”). Although thousands of fossil remains of the “Mikrotia fauna” have been collected during extensive sampling campaigns carried out since the 1970’s, Paralutra garganensis was to date only represented by the type specimens. The recent revision of material belonging to the “Mikrotia fauna” housed in Museum collections in Firenze and Torino (Italy) and Leiden (Netherlands) has allowed the identification of the specimens described herein and, furthermore, has highlighted new evidence regarding the ecology of the species. The latter findings in turn broaden our understanding to date of the ecological structure of the “Mikrotia fauna”.