Evolutionary Process from Mockina bidentata to Parvigondolella andrusovi: Evidence from the Pizzo Mondello Section, Sicily, Italy

During their last phase of evolution, the pectiniform conodont elements manifested an evident trend of simplification and miniaturization. This phase started from the late Norian (Sevatian) in the Late Triassic and the evolutionary process of genus Mockina to Parvigondolella, in particular between Mockina bidentata and Parvigondolella andrusovi, is one of the most significant examples. Parvigondolella has been reported worldwide since it was first described in the early 1970s. However, it has recently been suggested that genus Parvigondolella is an ecostratigraphic morphotype of genus Mockina, and thus a phenotype controlled by the environmental conditions, and not an independent taxon. In the Pizzo Mondello Section (Sicily, Italy), transitional forms between M. bidentata and P. andrusovi have been found at different evolutionary stages. We have investigated the oceanic conditions at the time by using redox-sensitive elements (Mn, Fe, V, Cr, and Ni) and seawater temperatures from biogenetic \u3b418Ophos to understand the possible environmental influences on the phylogenetic evolution between Mockina and Parvigondolella. The geochemical and isotope analyses indicate that the redox condition and temperature were stable during the evolution of genus Parvigondolella in Pizzo Mondello, confirming that genus Parvigondolella is a real taxon and not a phenotype. A new conodont species named Parvigondolella ciarapicae n. sp. is described here for the first time

Neuroimaging and cognitive changes during deja vu.

Objective: The cause or the physiological role of de?ja? vu (DV) in healthy people is unknown. The pathophysiology of DV-type epileptic aura is also unresolved. Here we describe a 22-year-old woman treated with deep brain stimulation (DBS) of the left internal globus pallidus for hemidystonia. At certain stimulation settings, DBS elicited reproducible episodes of DV. Methods: Neuropsychological tests and single-photon-emission computed tomography (SPECT) were performed during DBS-evoked DV and during normal DBS stimulation without DV. Results: SPECT during DBS-evoked DV revealed hyperperfusion of the right (contralateral to the electrode) hippocampus and other limbic structures. Neuropsychological examinations performed during several evoked DV episodes revealed disturbances in nonverbal memory. Conclusion: Our results confirm the role of mesiotemporal structures in the pathogenesis of DV. We hypothesize that individual neuroanatomy and disturbances in gamma oscillations or in the dopaminergic system played a role in DBS-elicited DV in our patient. ? 2008 Elsevier Inc. All rights reserved