New non-dino papers with free pdfs:
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Henrik Richard Grunert, Neil Brocklehurst & JÃrg FrÃbisch (2019)
Diversity and Disparity of Therocephalia: Macroevolutionary Patterns through Two Mass Extinctions.
Scientific Reports 9, Article number: 5063Â
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Mass extinctions have the potential to substantially alter the evolutionary trends in a clade. If new regions of ecospace are made available, the clade may radiate. If, on the other hand, the clade passes through an evolutionary âbottleneckâ by substantially reducing its species richness, then subsequent radiations may be restricted in the disparity they attain. Here we compare the patterns of diversity and disparity in the Therocephalia, a diverse lineage of amniotes that survived two mass extinction events. We use time calibrated phylogeny and discrete character data to assess macroevolutionary patterns. The two are coupled through the early history of therocephalians, including a radiation following the late Guadalupian extinction. Diversity becomes decoupled from disparity across the end-Permian mass extinction. The number of species decreases throughout the Early Triassic and never recovers. However, while disparity briefly decreases across the extinction boundary, it recovers and remains high until the Middle Triassic.
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Andrea Tintori (2019)
Predators and preys: A case history For Saurichthys (Costasaurichthys) costasquamosus Rieppel, 1985 from the Ladinian of Lombardy (Italy).
Rivista Italiana di Paleontologia e Stratigrafia 125(1): 171-182
A large specimen of Saurichthys (Costasaurichthys) costasquamosus from the lower Ladinian of the Northern Grigna mountain is described. It is an incomplete specimen, lacking the caudal region, and showing gut content. This latter consists of totally scattered remains of at least two specimens of adult Ctenognathichthys bellottii, a medium size fish quite common in this fossil assemblage. Saurichthys has been always considered an active predator on small fishes, but it cannot be the case for this specimen, with remains in the gut are totally disarticulated and evenly scattered all along the abdomen. Scavenging on floating carcasses is proposed, the hypothesis being also supported by the common preservation of Ctenognathichthys as incomplete individuals. Although the Saurichthys specimen shows some 'in situ' disarticulation, caudal region elements are totally missing on the slab yielding the anterior part of the fish. As for other large Saurichthys specimens from the same site, it is supposed that this is the result of a predation by a much larger marine organism, possibly an ichthyosaur.
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