Triassic marine reptiles gave birth to live young

Article Abstract:

A report on two gravid specimens of Keichousaurus hui Young from the Middle Triassic of China is described. These exquisitely preserved specimens not only provide the first unequivocal evidence of reproductive mode and sexual dimorphism in sauropterygians, but also indicate that viviparity could be expedited by the evolution of a movable pelvis in pachypleurosaurs, which has implications for the reproductive pattern of other sauropterygians and Mesozoic marine reptiles.

Animal reproduction, Dimorphism (Biology), Sauropterygia, Sauropterygians

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Pterosaur egg with a leathery shell

Article Abstract:

The study describes pterosaur egg whose exquisite preservation indicates that the shell structure was soft and leathery. The new pterosaur egg with its embryo was collected from the Jingangshan Beds of the Yixian Formation in the Jingangshan area of Liaoning, China and concluded that this egg had a soft, leathery shell, similar to those widely found among sphenodonts, squamates, crocodiles and turtles.

Reptiles, Fossil, Fossil reptiles, Pterosauria, Pterosaurs

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Convergent dental adaptations in pseudo-tribosphenic and tribosphenic mammals

Article Abstract:

An analysis describes the convergent dental adaptations observed in pseudo-tribosphenic and tribosphenic mammals. The results prove that the Mesozoic mammals exhibit greater dental evolution than their extant descendants.

Physiological aspects, Phylogeny, Extinct mammals, Molars

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