Morphology of the earliest reconstructable tetrapod Parmastega aelidae.

The known diversity of tetrapods of the Devonian period has increased markedly in recent decades, but their fossil record consists mostly of tantalizing fragments1-15. The framework for interpreting the morphology and palaeobiology of Devonian tetrapods is dominated by the near complete fossils of Ichthyostega and Acanthostega; the less complete, but partly reconstructable, Ventastega and Tulerpeton have supporting roles2,4,16-34. All four of these genera date to the late Famennian age (about 365-359 million years ago)-they are 10 million years younger than the earliest known tetrapod fragments5,10, and nearly 30 million years younger than the oldest known tetrapod footprints35. Here we describe Parmastega aelidae gen. et sp. nov., a tetrapod from Russia dated to the earliest Famennian age (about 372 million years ago), represented by three-dimensional material that enables the reconstruction of the skull and shoulder girdle. The raised orbits, lateral line canals and weakly ossified postcranial skeleton of P. aelidae suggest a largely aquatic, surface-cruising animal. In Bayesian and parsimony-based phylogenetic analyses, the majority of trees place Parmastega as a sister group to all other tetrapods

Sea surface temperature anomalies near South Georgia: relationships with the Pacific El Nino regions

The data set of Reynolds and Smith [1994] is used to describe temporal variability in sea surface temperature (SST) at South Georgia. Time series analysis indicates that high levels of autocorrelation are present, with periodicity evident in temperature anomalies at lag periods of approximately 4 years. Cross-correlation analyses with data describing the El Nin˜o regions of the Pacific indicate that variability at South Georgia reflects temperature fluctuations in the Pacific. This relationship is temporally separated, with the Pacific leading South Georgia by approximately 3 years and with the west Pacific showing the strongest cross correlation. Historic data describing the west Pacific show that patterns of variability have evolved through time and that the strong 4 year periodicity evident in recent years was not present in earlier records. The correlation between the west Pacific and South Georgia has also varied through time and the relationship is currently weaker than it has been over the past 19 years. The results are discussed in the context of a circumpolar precession of anomalies, transferring variability from the Pacific into the Atlantic