منابع مشابه
Deep-Time Phylogenetic Clustering of Extinctions in an Evolutionarily Dynamic Clade (Early Jurassic Ammonites)
Conservation biologists and palaeontologists are increasingly investigating the phylogenetic distribution of extinctions and its evolutionary consequences. However, the dearth of palaeontological studies on that subject and the lack of methodological consensus hamper our understanding of that major evolutionary phenomenon. Here we address this issue by (i) reviewing the approaches used to quant...
متن کاملMorphostructural constraints and phylogenetic overprint on sutural frilling in Late Jurassic ammonites
The functional signi cance of frilled septa and complex sutures in ammonoids has generated ongoing debate. The ‘classic’ hypothesis envisages ammonoid shells and septa as designed for resisting ambient hydrostatic pressure, complex sutures being the evidence of strength in shells for colonization of deep habitats. Here we address the ‘suture problem’, focusing on the analysis and interpretatio...
متن کاملToarcian oceanic anoxic event: An assessment of global causes using belemnite C isotope records
[1] Two hypotheses have been proposed to explain simultaneous large negative excursions (up to 7% PeeDee belemnite) in bulk carbonate (dCcarb) and organic carbon isotope records (d Corg) from black shales marking the Toarcian oceanic anoxic event (T-OAE). The first explanation envisions recycling of dissolved inorganic carbon (DIC) with a light isotopic signature into the photic zone from the l...
متن کاملBasinal restriction, black shales, Re-Os dating, and the Early Toarcian (Jurassic) oceanic anoxic event
[1] Profiles of Mo/total organic carbon (TOC) through the Lower Toarcian black shales of the Cleveland Basin, Yorkshire, United Kingdom, and the Posidonia shale of Germany and Switzerland reveal water mass restriction during the interval from late tenuicostatum Zone times to early bifrons Zone times, times which include that of the putative Early Toarcian oceanic anoxic event. The degree of res...
متن کاملMorphomechanics and Developmental Constraints in the Evolution of Ammonites Shell Form.
The idea that physical processes involved in biological development underlie morphogenetic rules and channel morphological evolution has been central to the rise of evolutionary developmental biology. Here, we explore this idea in the context of seashell morphogenesis. We show that a morphomechanical model predicts the effects of variations in shell shape on the ornamental pattern in ammonites,...
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ژورنال
عنوان ژورنال: Quarterly Journal of the Geological Society
سال: 1903
ISSN: 0370-291X
DOI: 10.1144/gsl.jgs.1903.059.01-04.42