Bollettino SPI Vol. 62 (1)

Published in June 2023


  • Holland S.M. (2023) – INVITED PAPER – OPEN ACCESS!

The contrasting controls on the occurrence of fossils in marine and nonmarine systems
pp. 1-25
doi: 10.4435/BSPI.2023.02


Stratigraphy is the first-order control on the fossil record. The formation of sedimentary basins dominates this control over large spatial (> 100 km) and long temporal scales (> 10 myr), with sequence-stratigraphic architecture becoming dominant over shorter time scales as low as 10 kyr. Numerical modeling of siliciclastic shallow-marine and nonmarine settings provides a framework for predictions about the structure of the fossil record. Despite the nearly limitless range of possible stratigraphic architectures, these simplify into three main contexts: slow relative rise in sea level, rapid relative rise in sea level, and relative fall in sea level. Each produces characteristic stratigraphic changes in the structure of the fossil record. For example, clusters of first and last occurrences in marine systems are expected at subaerial unconformities, nondepositional surfaces (such as downlap surfaces), flooding surfaces, and surfaces of forced regression, whereas such clusters are expected only at subaerial unconformities in nonmarine systems. Similarly, community composition will change predictably in marine and nonmarine systems, reflecting the distribution of species along ecological gradients in water depth and elevation. Numerous field studies demonstrate that these effects are pervasive. Any paleontological study that is grounded in where fossils occur must therefore consider these effects before making any interpretations of biological processes. Several studies are highlighted that demonstrate how to isolate the stratigraphic controls on fossil occurrences and reach well-grounded interpretations of mass extinctions, ecosystem changes, morphological evolution, and phylogenetic history. Areas of promising avenues of research are presented, including the role of stratigraphic architecture over long time scales (> 10s-100s myr), the development of models specific to shallow-water carbonates, and field-based studies of the role of nonmarine alluvial and lacustrine stratigraphic architecture.

Supplementary Online Material
  • Psarras C., Merle D., Antonarakou A. & Koskeridou E. (2023)

Late Miocene Conidae (Mollusca: Gastropoda) of Crete, Greece. Part 3: subgenus Conus (Monteiroconus) da Motta, 1991
pp. 27-52
doi: 10.4435/BSPI.2023.01


Late Miocene Conidae of Crete (Greece) have been recently evaluated for the genera Conilithes, Conus (Kalloconus), Conus (Lautoconus), Conus (Stephanoconus) and Conus (Plagioconus). We conclude the study of the family herein by discussing the subgenus Conus (Monteiroconus). With the aid of UV light, five species are discussed in detail, Conus (Monteiroconus) antiquus Lamarck, 1810, Conus (Monteiroconus) hoernesi Doderlein, 1863, Conus (Monteiroconus) karamanensis Erünal-Erentöz, 1958 and two species left in open nomenclature. Tortonian Conidae of Crete now sum up to thirty-three species, three of them being endemic to Crete. Knowledge of this fauna adds to that of the Tortonian Conidae of the Eastern Proto-Mediterranean and helps to fill a gap between the Middle Miocene Conidae faunas from the Paratethys and Eastern Proto-Mediterranean and the Late Miocene Central and Western Proto-Mediterranean assemblages.

  • Forte G., Lanthaler B., Morelli C., Krainer K., Trümper S. & Kustatscher E. (2023)

The Kungurian (lower Permian) plant fossil assemblage of Sinich/Sinigo (NE Italy)
pp. 53-83
doi: 10.4435/BSPI.2023.03


The sedimentary succession of the Sinich/Sinigo Basin is one of the oldest sedimentary intercalations of the Cisuralian (lower Permian) Athesian Volcanic Group of the Bozen/Bolzano area. The plant remains that were deposited in its alluvial and lacustrine sediments are middle Kungurian in age and are characterized by a wide variety of preservation types. The nearly 600 specimens from Sinich/Sinigo include permineralized stems, compressions/impressions and casts/molds, which belong to various plant groups, such as putative lycopsids, sphenophytes, ferns, seed ferns, cordaitaleans and conifers. Strata of the Sinich/Sinigo Basin yield one of the richest and best documented Kungurian plant assemblages of eastern paleoequatorial Pangea. The conifers are represented by both walchian and more derived voltzian Voltziales, forming the earliest co-occurrence of these two groups in eastern Pangea. The three-dimensional preservation mode revealed xeromorphic features in more than one conifer species, such as the presence of fleshy and “deciduous” leaves in both walchian and voltzian conifers. These morphological features were probably more common during the early Permian, being an adaptation to aridity. The comparison of the Sinich/Sinigo collection with other Kungurian plant assemblages strengthens the assumption of more widespread semi-arid to arid conditions in the middle-late Kungurian of the Southern Alps, whereas the strata and the presence of hygrophytic elements indicate that increased rainfall and flooding events could have occasionally occurred.

  • Conti S. & Serventi P. (2023)

Paleoecology of a new Gyrolithes ichnospecies as a component of a compound trace fossil from the Middle Miocene Marnoso-arenacea Formation (northern Apennines, Italy)
pp. 85-103
doi: 10.4435/BSPI.2023.04


The new ichnospecies Gyrolithes fibonaccii n. isp. is a helical marine trace fossil characterized by a unique morphology resembling a sheep horn. Gyrolithes fibonaccii n. isp. forms a “compound system” with Thalassinoides and suggests a long-lasting burrowing activity of the inferred decapod crustacean producer. The trace is widespread throughout the Prati Piani interval of the Miocene Marnoso-arenacea Formation (northern Apennines, Italy) and expands the current geographic and environmental distribution of Gyrolithes into this pelitic interval. Peculiar fine-grained horizons within the Langhian-Serravallian succession of the Marnoso-arenacea Fm. are associated with seep-carbonates and small-scale sediment instabilities, as well as abundant glauconite-rich beds. Despite the well-established sedimentologic significance of the arenaceous succession, the origin of the fine-grained intervals of the Marnoso-arenacea Fm. hosting seep-carbonates should be reconsidered in the light of the expulsion of methane rich fluids. The paleoecology of this “compound system” indicates a quiet depositional regime with a low sedimentation rate and confirms that the Prati Piani domain represented an intrabasinal high, segmenting the inner foredeep of the Marnoso-arenacea Fm.

  • Bonci M.C., Basso D., Briguglio A. & Piazza M. (2023)

In Memory of Grazia Vannucci (1943-2022)
pp. i-vi