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Tselfatia formosa Arambourg, 1943 (Pisces, Actinopterygii) dal Cretaceo Superiore del Trentino (Italia settentrionale).
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"Lithiotis” beds of the Rotzo Formation (Calcari Grigi Group, Lower Jurassic) from Albaredo (Rovereto, Trento)
No full textSome spectacular bivalve banks of the Lithiotis Facies are described here. They are located in the upper part of the Rotzo Formation (Lower Jurassic). An excellent preservation state of the specimens, the darkness and scarce re-crystallisation of the matrix, and the broad lateral extension of the mounds allowed us a reliable taxonomic classification and the reconstruction of bank geometries. These banks were produced by Lithioperna and Cochlearites
A review of Rhynchosauroides tyrolicus abel 1926 ichnospecies (Middle Triassic: Anisian-Ladinian) and some inferences on Rhynchosauroides trackmaker
No full textSkin remains in a juvenile Macrocnemus bassanii Nopcsa (Reptilia, Prolacertiformes) from the Middle Triassic of Northern Italy
No full textLower and Middle Triassic footprint-based Biochronology in the Italian Southern Alps
Full text linkThe Early and Middle Triassic ichnoassociations of the Italian Southern Alps appear particularly important due to their excellent state of preservation and the ample vertical distribution of the dated trampled levels. On the basis of the ranges of single ichnotaxa, it is possible to define a series of different associations, characterized by different evolutionary stages. They correspond to informal evolutionary units that can be estabilished as faunal units (FUs).
The Scythian is characterized by the presence of Rhynchosauroides schochardti that disappears in the Anisian. In the Anisian, characterized by the appearance of Rhynchosauroides tirolicus) a progressive increase in the complexity of the ichnoassociations from the Bithynian to the Illyrian is documented. In the Bithynian - Early Pelsonian interval the faunal assemblage is dominated by Parasynaptichnium gracilis and Synaptichnium pseudosuchoides. The Early Pelsonian - Early Illyrian interval is characterized by the dominance of Isochirotherium delicatum and Brachychirotherium circaparvum
I Lavini di Marco: aspetti geologico-strutturali
No full textI Lavini di Marco, dove nel 1991 sono state scoperte numerose piste di dinosauri, vengono inquadrati dal punto di vista strutturale nell'ambito delle Alpi Meridionali. L'analisi delle strutture di deformazione delle rocce dei Lavini di Marco permette di evidenziare che esistono due gruppi di strutture: quelle prodotte da deformazioni precedenti la frana (talora probabilmente riattivate anche in epoca recente) e quelle conseguenti o posteriori alla frana. Alle prime appartengono la grande omoclinale del Monte Zugna, le faglie, le flessure e il sistema di vene, che sono la registrazione delle deformazioni tettoniche avvenute a scala regionale; alle seconde appartengono le pieghe superficiali e le fessure di tensione, che sono invece l'effetto dei movimenti gravitativi di pacchi di strati conseguenti all'innesco del movimento franoso. In sostanza, le prime strutture predispongono e controllano la geometria della frana, mentre le seconde si evolvono secondo i vincoli predisposti dalle prime
A review of the concepts of ‘axony’ and their bearing on tetrapod ichnology
No full textTwo meanings of the term axony are found in the ichnological literature. Multiple meanings may prove to be a double-edge sword, complicating scientific communication. In vertebrate ichnology the first meaning of axony relies on aspects of locomotion related to the body weight support and propulsive thrust. A second one concerns axony as a purely geometric and dimensional descriptor. These approaches are based on a static view of the impression process, implying the loss of much important information. Here we report an analysis of shallowly impressed footprints referred to the ichnotaxa Ichniotherium sphaerodactylum and Dimetropus osageorum. The analysis was carried out by considering the track registration as a dynamic process and attempting to identify and describe axony conditions during movements. Variations in the axony conditions can be understood in the light of the producer’s foot anatomy and the reciprocal relations between foot bone elements. The concept of axony can be a useful tool in ichnological practice only when it is related to the complex dynamic of locomotion and the resulting track registration. It can help in restoring the interconnections between track and trackmaker, re-establishing the biological significance of tetrapod footprints
On continuation-passing transformations and expected cost analysis
Full text linkWe define a continuation-passing style (CPS) translation for a typed λ-calculus with probabilistic choice, unbounded recursion, and a tick operator - for modeling cost. The target language is a (non-probabilistic) λ-calculus, enriched with a type of extended positive reals and a fixpoint operator. We then show that applying the CPS transform of an expression M to the continuation λ v. 0 yields the expected cost of M. We also introduce a formal system for higher-order logic, called EHOL, prove it sound, and show it can derive tight upper bounds on the expected cost of classic examples, including Coupon Collector and Random Walk. Moreover, we relate our translation to Kaminski et al.'s ert-calculus, showing that the latter can be recovered by applying our CPS translation to (a generalization of) the classic embedding of imperative programs into λ-calculus. Finally, we prove that the CPS transform of an expression can also be used to compute pre-expectations and to reason about almost sure termination
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