scholarly journals High resolution integrated microbiostratigraphy of the Lower Jurassic (late Pliensbachian–early Toarcian) of central Italy

1998 ◽  
Vol 17 (2) ◽  
pp. 153-172 ◽  
Author(s):  
Raffaella Bucefalo Palliani ◽  
Emanuela Mattioli
Keyword(s):  
High Resolution ◽  
Evolutionary History ◽  
Central Italy ◽  
Lower Jurassic ◽  
High Potential ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Dinoflagellate Cyst ◽  
History Of ◽  
Global Events

Abstract. The integrated use of calcareous nannofossil and dinoflagellate cyst events in a study of the late Pliensbachian–early Toarcian interval in central Italy has yielded a high resolution biostratigraphy. The use of both the first and last occurrences of selected taxa belonging to the two phytoplankton groups allows the dating of the sediments with a very refined detail, even when lithologies are unfavourable to the preservation of one fossil group. The evolutionary history of calcareous nannofossils and dinoflagellate cysts during the early Jurassic and its links with global events are responsible for the high potential of this integrated biostratigraphy.

scholarly journals The calcareous nannofossil <i>Prinsiosphaera</i> achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the δ<sup>13</sup>C of bulk carbonate

2013 ◽  
Vol 10 (5) ◽  
pp. 7989-8025 ◽  
Author(s):  
N. Preto ◽  
C. Agnini ◽  
M. Rigo ◽  
M. Sprovieri ◽  
H. Westphal
Keyword(s):  
Global Ocean ◽  
Late Triassic ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Western Tethys ◽  
Carbonate Sedimentation ◽  
History Of ◽  
Calcareous Plankton ◽  
Inorganic Carbon Cycle

Abstract. The onset of pelagic biomineralization marked a milestone in the history of the long term inorganic carbon cycle: as soon as calcareous nannofossils became major limestone producers, the pH and supersaturation state of the global ocean were stabilized (the so-called Mid Mesozoic Revolution). But although it is known that calcareous nannofossils were abundant already by the end of the Triassic, no estimates exist on their contribution to hemipelagic carbonate sedimentation. With this work, we estimate the volume proportion of Prinsiosphaera, the dominant Late Triassic calcareous nannofossil, in hemipelagic and pelagic carbonates of western Tethys. The investigated Upper Triassic lime mudstones are composed essentially of microspar and tests of calcareous nannofossils, plus minor bioclasts. Prinsiosphaera became a significant component of lime mudstones since the late Norian, and was contributing up to ca. 60% of the carbonate by the late Rhaetian in periplatform environments with hemipelagic sedimentation. The increasing proportion of Prinsiosphaera in upper Rhaetian hemipelagic lime mudstones is paralleled by a increase of the δ13C of bulk carbonate. We interpreted this isotopic trend as related to the diagenesis of microspar, which incorporated respired organic carbon with a low δ13C when it formed during shallow burial. As the proportion of nannofossil tests increased, the contribution of microspar with low δ13C diminished, determining the isotopic trend. We suggest that a similar diagenetic effect may be observed in many Mesozoic limestones with a significant, but not yet dominant, proportion of calcareous plankton.

scholarly journals A new early-branching armoured dinosaur from the Lower Jurassic of southwestern China

2021 ◽  
Author(s):  
Xi Yao ◽  
Paul Barrett ◽  
Lei Yang ◽  
Xing Xu ◽  
Shundong Bi
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Yunnan Province ◽  
Morphological Diversity ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
New Taxon ◽  
Unique Combination ◽  
Geographic Spread ◽  
History Of

The early evolutionary history of the armoured dinosaurs (Thyreophora) is obscured by its patchily distributed fossil record and by conflicting views on the relationships of its Early Jurassic representatives. Here, we describe an early-diverging thyreophoran from the Lower Jurassic Fengjiahe Formation of Yunnan Province, China, on the basis of an associated partial skeleton that includes skull, axial, limb and armour elements. It can be diagnosed as a new taxon based on numerous cranial and postcranial autapomorphies and is further distinguished from all other thyreophorans by a unique combination of character states. Although the robust postcranium is similar to that of more deeply nested ankylosaurs and stegosaurs, phylogenetic analysis recovers it as either the sister taxon of Emausaurus or of the clade Scelidosaurus and Eurypoda. This new taxon, Yuxisaurus kopchicki, represents the first valid thyreophoran dinosaur to be described from the Early Jurassic of Asia and confirms the rapid geographic spread and diversification of the clade after its first appearance in the Hettangian. Its heavy build and distinctive armour also hint at previously unrealised morphological diversity early in the clade history.

scholarly journals The calcareous nannofossil <i>Prinsiosphaera</i> achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the <i>δ</i><sup>13</sup>C of bulk carbonate

2013 ◽  
Vol 10 (9) ◽  
pp. 6053-6068 ◽  
Author(s):  
N. Preto ◽  
C. Agnini ◽  
M. Rigo ◽  
M. Sprovieri ◽  
H. Westphal
Keyword(s):  
Global Ocean ◽  
Late Triassic ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Western Tethys ◽  
Carbonate Sedimentation ◽  
History Of ◽  
Calcareous Plankton ◽  
Inorganic Carbon Cycle

Abstract. The onset of pelagic biomineralization was a milestone in the history of the long-term inorganic carbon cycle: as soon as calcareous nannofossils became major limestone producers, the pH and supersaturation state of the global ocean were stabilized (the so-called mid-Mesozoic revolution). But although it is known that calcareous nannofossils were abundant already by the end of the Triassic, no estimates exist on their contribution to hemipelagic carbonate sedimentation. With this work, we estimate the volume proportion of Prinsiosphaera, the dominant late Triassic calcareous nannofossil, in hemipelagic and pelagic carbonates of western Tethys. The investigated Upper Triassic lime mudstones are composed essentially of microspar and tests of calcareous nannofossils, plus minor bioclasts. Prinsiosphaera had become a significant component of lime mudstones since the late Norian, and was contributing up to ca. 60% of the carbonate by the late Rhaetian in periplatform environments with hemipelagic sedimentation. The increasing proportion of Prinsiosphaera in upper Rhaetian hemipelagic lime mudstones is paralleled by an increase of the δ13C of bulk carbonate. We interpreted this isotopic trend as related to the diagenesis of microspar, which incorporated respired organic carbon with a low δ13C when it formed during shallow burial. As the proportion of nannofossil tests increased, the contribution of microspar with low δ13C diminished, determining the isotopic trend. We suggest that a similar diagenetic effect may be observed in many Mesozoic limestones with a significant, but not yet dominant, proportion of calcareous plankton.

The evolutionary history of sauropod dinosaurs

1995 ◽  
Vol 349 (1330) ◽  
pp. 365-390 ◽  
Keyword(s):  
Evolutionary History ◽  
Upper Cretaceous ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Lower Jurassic ◽  
Geographic Isolation ◽  
Future Studies ◽  
New Family ◽  
Restricted Sense ◽  
History Of

Most recent studies of dinosaur phylogeny have concentrated on theropods and ornithischians. As a result, the evolutionary relationships of sauropod dinosaurs are poorly understood. In this paper previous studies of sauropod phylogeny are reviewed and contrasted with the results of a recent cladistic analysis. This analysis forms the basis for a reconstruction of sauropod phylogeny. Sauropods diverged from other dinosaurs at some time in the Upper Triassic, but a large part of their early history is totally unknown. Vulcanodon is currently the most primitive sauropod. Many, but perhaps not all, of the Jurassic Chinese sauropods form a monophyletic radiation (the Euhelopodidae) which may reflect the geographic isolation of China during the Lower Jurassic. Members of the Euhelopodidae, such as Mamenchisaurus , are not considered to be closely related to the Diplodocidae. ‘Forked’ chevrons, which have played such an important role in previous studies of sauropod phylogeny, are here considered to have evolved twice within the Sauropoda. This convergence may reflect a correlation between chevron shape and the use of the tail as a weapon within these two sauropod families. The ‘Neosauropoda’ (sister group to the Euhelopodidae) contains the Brachiosauridae, Camarasauridae and the new superfamilies Titanosauroidea and Diplodocoidea. The Cetiosauridae (here defined in a rather restricted sense) is also provisionally included within the Neosauropoda, but may be removed in future studies. The enigmatic Upper Cretaceous sauropod, Opisthocoelicaudia , is thought to be the sister taxon to the Titanosauridae and not a camarasaurid as previously suggested. The Diplodocoidea contains two well established families, the Dicraeosauridae and Diplodocidae, and the new family Nemegtosauridae. Finally, an overview of sauropod phylogeny is compared with recently published palaeogeographic reconstructions. There are many difficulties associated with the analysis of sauropod biogeographic distribution. Nevertheless, some aspects of sauropod phylogeny may be linked to the break-up of Laurasia and Gondwanaland during the Jurassic and Cretaceous.

scholarly journals High-Resolution Molecular Epidemiology and Evolutionary History of HIV-1 Subtypes in Albania

PLoS ONE ◽  
2008 ◽  
Vol 3 (1) ◽  
pp. e1390 ◽  
Author(s):  
Marco Salemi ◽  
Tulio de Oliveira ◽  
Massimo Ciccozzi ◽  
Giovanni Rezza ◽  
Maureen M. Goodenow
Keyword(s):  
High Resolution ◽  
Molecular Epidemiology ◽  
Evolutionary History ◽  
History Of ◽  
Hiv 1

First Italian record for a partial Isabelline colouration in a European mole, Talpa europaea

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leonardo Brustenga
Keyword(s):  
Evolutionary History ◽  
Scientific Literature ◽  
Central Italy ◽  
Common Species ◽  
Talpa Europaea ◽  
European Mole ◽  
History Of

Abstract The European mole Talpa europaea Linnaeus, 1758 is a quite common species in Central Italy. I report the first Isabelline individual of this species recorded in the scientific literature. Actually, this species is quite widespread throughout Europe, but coat-colouration anomalies have never been described in Italian mole populations. Further research is therefore needed to determine the percentage of occurrence of anomalous individuals and the evolutionary history of coat anomalies in moles.

scholarly journals Population genomics of wall lizards reflects the dynamic history of the Mediterranean Basin

2021 ◽  
Author(s):  
Weizhao Yang ◽  
Nathalie Feiner ◽  
Daniele Salvi ◽  
Hanna Laakkonen ◽  
Daniel Jablonski ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Mediterranean Basin ◽  
Evolutionary History ◽  
Central Italy ◽  
Hybrid Origin ◽  
Recent Common Ancestor ◽  
Extant Species ◽  
History Of ◽  
The Mediterranean ◽  
The Mediterranean Basin

The Mediterranean Basin has experienced extensive change in geology and climate over the past six million years. Yet, the relative importance of key geological events for the distribution and genetic structure of the Mediterranean fauna remains poorly understood. Here, we use population genomic and phylogenomic analyses to establish the evolutionary history and genetic structure of common wall lizards (Podarcis muralis). This species is particularly informative because, in contrast to other Mediterranean lizards, it is widespread across the Iberian, Italian, and Balkan peninsulas, and in extra-Mediterranean regions. We found strong support for six major lineages within P. muralis, which were largely discordant with the phylogenetic relationship of mitochondrial DNA. The most recent common ancestor of extant P. muralis was likely distributed in the Italian Peninsula, and experienced an Out-of-Italy expansion following the Messinian salinity crisis (~5 Mya), resulting in the differentiation into the extant lineages on the Iberian, Italian and Balkan peninsulas. Introgression analysis revealed that both inter- and intraspecific gene flow have been pervasive throughout the evolutionary history of P. muralis. For example, the Southern Italy lineage has a hybrid origin, formed through admixture between the Central Italy lineage and an ancient lineage that was the sister to all other P. muralis. More recent genetic differentiation is associated with the onset of the Quaternary glaciations, which influenced population dynamics and genetic diversity of contemporary lineages. These results demonstrate the pervasive role of Mediterranean geology and climate for the evolutionary history and population genetic structure of extant species.

scholarly journals New fossils of Jurassic ophiurid brittle stars (Ophiuroidea; Ophiurida) provide evidence for early clade evolution in the deep sea

2021 ◽  
Author(s):  
Ben Thuy ◽  
Lea D. Numberger-Thuy ◽  
Tania Pineda-Enriquez
Keyword(s):  
Phylogenetic Analysis ◽  
New Taxa ◽  
Deep Sea ◽  
Fossil Record ◽  
Evolutionary History ◽  
Lower Jurassic ◽  
Brittle Stars ◽  
Family Level ◽  
History Of ◽  
Basal Position

Understanding of the evolutionary history of the ophiuroids, or brittle stars, is hampered by a patchy knowledge of the fossil record. Especially the stem members of the living clades are poorly known, resulting in blurry concepts of the early clade evolution and imprecise estimates of divergence ages. Here, we describe new ophiuroid fossil from the Lower Jurassic of France, Luxembourg, and Austria and introduce the new taxa Ophiogojira labadiei gen. et sp. nov. from lower Pliensbachian shallow sublittoral deposits, Ophiogojira andreui gen. et sp. nov. from lower Toarcian shallow sublittoral deposits, and Ophioduplantiera noctiluca gen. et sp. nov. from late Sinemurian to lower Pliensbachian bathyal deposits. A Bayesian morphological phylogenetic analysis shows that Ophiogojira holds a basal position within the order Ophiurida, whereas Ophioduplantiera has a more crownward position within the ophiurid family Ophiuridae. The position of Ophioduplantiera in the evolutionary tree suggests that family-level divergences within the Ophiurida must have occurred before the late Sinemurian, and that ancient slope environments played an important role in fostering early clade evolution.

scholarly journals New fossils of Jurassic ophiurid brittle stars (Ophiuroidea; Ophiurida) provide evidence for early clade evolution in the deep sea

2021 ◽  
Vol 8 (8) ◽  
pp. 210643
Author(s):  
Ben Thuy ◽  
Lea D. Numberger-Thuy ◽  
Tania Pineda-Enríquez
Keyword(s):  
Phylogenetic Analysis ◽  
New Taxa ◽  
Deep Sea ◽  
Fossil Record ◽  
Evolutionary History ◽  
Lower Jurassic ◽  
Brittle Stars ◽  
Family Level ◽  
History Of ◽  
Basal Position

Understanding of the evolutionary history of the ophiuroids, or brittle stars, is hampered by a patchy knowledge of the fossil record. Especially, the stem members of the living clades are poorly known, resulting in blurry concepts of the early clade evolution and imprecise estimates of divergence ages. Here, we describe new ophiuroid fossil from the Lower Jurassic of France, Luxembourg and Austria and introduce the new taxa Ophiogojira labadiei gen. et sp. nov. from lower Pliensbachian shallow sublittoral deposits, Ophiogojira andreui gen. et sp. nov. from lower Toarcian shallow sublittoral deposits and Ophioduplantiera noctiluca gen. et sp. nov. from late Sinemurian to lower Pliensbachian bathyal deposits. A Bayesian morphological phylogenetic analysis shows that Ophiogojira holds a basal position within the order Ophiurida, whereas Ophioduplantiera has a more crownward position within the ophiurid family Ophiuridae. The position of Ophioduplantiera in the evolutionary tree suggests that family-level divergences within the Ophiurida must have occurred before the late Sinemurian, and that ancient slope environments played an important role in fostering early clade evolution.

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