Bollettino SPI Vol. 54 (3)

Published in December 2015


  • Mazza M. & Martínez-Pérez C. (2015)

Unravelling conodont (Conodonta) ontogenetic processes in the Late Triassic through growth series reconstructions and X-ray microtomography
pp. 161-186


The ontogenetic series of ten Carnian-Norian (Late Triassic) platform conodont species, belonging to the genera ParagondolellaCarnepigondolellaEpigondolella, and Metapolygnathus are reconstructed in this paper. The growth series are based on rich populations derived from almost monospecific samples from the upper Carnian-Rhaetian succession of Pizzo Mondello (Sicani Mountains, Western Sicily, Italy), a GSSP candidate for the Norian stage. Six to twelve ontogenetic stages have been recognized for each species, based on examination of more than 350 SEM photos, integrated with X-ray synchrotron microtomographic images of their internal structure. These findings have given rise to a revaluation of the systematics and the phylogenesis of the Late Triassic conodonts from an ontogenetic perspective, leading to important refinements of their biostratigraphy and to a reinterpretation of their evolutionary processes. Herein it is observed that conodonts develop a morphological identity already in their most juvenile stages, thus, for the first time, they now have a specific taxonomic identity. Changes to the stratigraphic ranges of important Epigondolella species such as E. rigoiE. triangularis, and E. uniformis are noted, and their First Appearing Data (FADs) now result younger in age, calling into question previous phylogenetic models. More articulated phylogenetic relationships with the carnepigondolellids have emerged, questioning the hypothesis that Epigondolella is a monophyletic group and suggesting the existence of different polyphyletic lineages deriving anagenetically from several Carnian Carnepigondolella species. Subsequently in the middle Norian the epigondolellids evolve into the genera MockinaParvigondolella, and Misikella, which show reduced dimensions and neotenic characters. The present study provides a tool for the interpretation of this evolutionary process. We observed that the morphologies of these three genera are analogous to progressive juvenile stages of the epigondolellids: the mockinae are comparable to early adult, late juvenile, and juvenile stages of the epigondolellids, while the parvigondolellids and the misikellae to their early juvenile stages. Consequently, it is deduced that the final evolutionary trend of conodonts in the Late Triassic is thus the result of a gradual process of progenesis that started already in the middle Norian.

  • Jaselli L. (2015)

The Lower Jurassic (Early Sinemurian) ophiuroid Palaeocoma milleri in the palaeontological collection of the Museo di Storia Naturale “Antonio Stoppani” (Italy)
pp. 187-195


The palaeontological collection of the Museo di Storia Naturale “Antonio Stoppani” (Venegono Inferiore, Varese, Italy) houses an ophiuroid assemblage that to date has not been studied as extensively as it deserves. The specimen examined herein is a light grey calcarenite block from the Early Jurassic successions of Mount Campo dei Fiori (Western Lombardy) and consists of well-preserved skeletal remains of a complete ventrally oriented and a nearly-complete dorsally oriented ophiuroid. These brittle star remains were collected together with other marine fossils that resemble the “Fauna of Saltrio”. Based on the lithological characteristics and faunal content, it is suggested herein that this specimen comes from the Early Sinemurian sediments of the Saltrio beds, exposed on the eastern side of Mount Campo dei Fiori. Taxonomic determination of the embedded brittle stars was performed through morphological analysis and comparison with other Early Jurassic ophiuroids already described in the literature. This study allowed these forms to be identified as belonging to Palaeocoma milleriPalaeocoma is an extinct genus of brittle stars ranging from the Middle Triassic (Ladinian) to the Lower Jurassic (Toarcian).

  • Bernor R.L., Sun B. & Chen Y. (2015)

Plesiohipparion shanxiense n. sp. from the Early Pleistocene (Nihowanian) of E Shanxi, China
pp. 197-210


Plesiohipparion is a genus of hipparionine horses that first appears in the latest Miocene of SW Tibet and becomes a common equid in the Pliocene of China. Plesiohipparion is distinct from the late Miocene clades HippotheriumHipparionCremohipparion and Sivalhippus and is related to the Chinese Proboscidipparion and African EurygnathohippusPlesiohipparion extended its range into Turkey, southwest Europe and Arctic Canada during the Pliocene. Plesiohipparion shanxiense n. sp. is the largest, and at the same time the youngest species of the genus. Plesiohipparion shanxiense n. sp. is most closely related to the earlier, smaller species Plesiohipparion houfenense differing in size, length of snout, length of the cheek tooth row, lack of any preorbital facial structures and elongate, narrow structure of the I3. Whereas Plesiohipparion likely originated in China, it dispersed westward to Turkey and Spain. Plesiohipparion is likely the sister taxon of the African Eurygnathohippus based on a number of shared-derived characters. Plesiohipparion shanxiense n. sp. would appear to be restricted to China and the terminal species of this clade.

  • Bannikov A.F. (2015)

A new genus for the Cenomanian ellimmichthyiform fishes from Lebanon and Mexico
pp. 211-218


A new genus and species of paraclupeid ellimmichthyiform, Scutatoclupea bacchiai, is described based on a single skeleton from the Cenomanian of Namoura, Lebanon. Scutatoclupea n. gen. differs greatly from the other paraclupeid genera in having much stronger ventral armor: the deep lateral wings of its abdominal scutes cover most of the abdominal cavity. The mid-Cretaceous species Triplomystus applegatei Alvarado-Ortega & Ovalles-Damián, 2008 from Mexico is referred to the new genus Scutatoclupea that is regarded as a sister taxon of Triplomystus. Both genera are unique among the clupeomorphs in having a postdorsal scute series.

  • Garbelli C. & Tintori A. (2015)

A preliminary study on the ornamentation patterns of ganoid scales in some Mesozoic actinopterygian fishes
pp. 219-228


Ganoid scales are one of the most common remains of vertebrates in the fossil record of Paleozoic and Mesozoic. Their
knowledge is important for the understanding of the paleobiology and evolution of actinopterygian fishes. The distinctive feature of these scales
is the outermost shiny layer of ganoine, an hyper-mineralized enamel-like tissue. During the Mesozoic, ganoid scales show a great variety of
shapes and very different patterns of ornamentation made of ganoine. The surface of scales may be from smooth to very ornamented, with a
relief arranged in tubercles, ridges, grooves or a combination of them. Here we present a preliminary study on the squamation of some Mesozoic
non-teleost actinopterygians in order to test the association between body shape and ganoine ornamentation. Using several morphological
descriptors, we built an empirical morphospace to compare ganoid scales ornamentation. The use of a quantitative method to describe
scales allows to test if there is a meaningful correlation between body shape and ganoine ornamentation in non-teleost actinopterygians.
We found an important association between body shape and scale ornamentation in the taxa under investigation. In particular, deep-bodied
fishes bear a more complex and variegate ornamentation than fusiform ones. This finding has important implications in our understanding
of non-teleost actinopterygians paleobiology. Since swimming activity is a primary function for fish and this is performed by the body acting
as an integrated unit, the correlation between body shape and ganoine ornamentation could be related to hydrodynamics. A quantitative test
of this hypothesis, however, would be desirable.

Supplementary Online Material 1
Supplementary Online Material 2
  • Sciuto F. & Meli A. (2015)

Ostracod association from Pleistocene sediments along the Ionian coast of SE Sicily
pp. 229-241


Ostracod assemblages from the Early Pleistocene clays and marls known as “blue-gray clays”, just below the limit with the Middle Pleistocene calcarenites referred to as “panchina”, have been studied in several outcrops along the Sicilian Ionian coast between Augusta and Syracuse. The ostracod fauna (obtained from fourteen samples) is well preserved and well diversified: a total of 53 taxa of ostracods have been identified, 44 at specific level and nine in open nomenclature. We compared the different ostracod associations found in the different sampling sites and these were subsequently compared with coeval ostracod associations belonging to different palaeogeographic domains. The ostracod associations, consist predominantly of Costa edwardsiiHenryhowella ex H. hirta group, Pterygocythereis siveteriCytheridea neapolitanaKrithe praetextaPterygocythereis jonesiiCimbaurila cimbaeformisCarinocythereis carinata and Aurila convexa. They may be interpreted as deriving from original populations living in environments ranging from the lower levels of the Infralittoral zone and the upper part of the Circalittoral zone. Particularly important from the ecological point of view is the presence in some samples of Bythocythere turgida. This species would indicate deposition of these sediments during the cold phases of the Pleistocene, a supposition moreover confirmed by the presence of the Northern Guests Arctica islandicaMacoma obliquaPseudamussium peslutrae, and Neptunea contraria.

  • Index of Volume 54