Africa is the only continent that now straddles arid zones located beneath the descending limbs of both the northern and southern Hadley cells, and it has done so since it became a distinct continent in the Early Cretaceous. Since that time, Africa has drifted tectonically some 12 degrees north and rotated approximately 45 degrees counterclockwise. This changing latitudinal setting and position of the landmass under the relatively stable Hadley Cells is manifested as southward migration of climatic zones over the past 132 million years. Data from kerogen, X-ray diffraction analysis of sedimentary matrix, carbon isotopes from shell samples and tooth enamel,new 40Ar/39Ar radiometric dates, pollen and plant macrofossils, and fossil vertebrates indicate a productive upwelling system adjacent to a coastal desert since the opening of the South Atlantic Ocean; however, the position of the coastal desert has migrated southward as Africa drifted north, resulting in today's Skeleton Coast and Benguela Current. This migration has had a profound effect on the placement of the West African coast relative to areas of high marine productivity and resulting extensive hydrocarbon deposits, on the placement of arid zones relative to the continent especially the Skeleton Coast desert, on the climatic history of the Congo Basin (which shows a Late Cretaceous decrease in aridity based on the relative abundance of analcime in the Samba core), and in reducing the southern temperate region of Africa from 17% of continental area during the Cretaceous to 2% today. We show here that these related geographic and environmental changes drove ecological and evolutionary adjustments in southern African floras and faunas, specifically with respect to the distribution of anthropoid primates, the occurrence of modern relicts such as the gnetalean Welwitschia mirabilis, endemism as in the case of ice plants, and mammalian adaption to an open environment as in springhares. Africa's tectonic drift through climate zones has been a first-order environmental determinant since the Early Cretaceous.

The Upper Jurassic of Portugal has a rich vertebrate fauna well documented from both body and trace fossils. Although the occurrence of crocodyles and pterosaurs is well documented from body fossils, trace fossils from both groups were unknown until now. Here we describe an isolated crocodyle-like track from Praia da Peralta and pterosaur tracks from the Kimmeridgian of Pedreira do Avelino, Sesimbra (Azóia Fm.) and Porto das Barcas, Lourinhã (Lourinhã Fm.). An enigmatic track suggests the possible presence of a small, tail-dragging tetrapod.
Possible track-makers are suggested based on the known Late Jurassic vertebrate fauna of Portugal.

Modern marine species populations are often evaluated in terms of bottom-up, resource limited structure, or top-down, predator controlled structure. In a larger timeframe, investiga- tion of physical drivers in marine tetrapod evolution relies on the recognition of patterns and the correlation in timing of physical events with biotic change. However, it has been dem- onstrated through the study of fossil cetaceans that a broader deep-time perspective within a top-down or bottom-up framework is informative. Here we examine the fossil record of &UHWDFHRXV PDULQH WHWUDSRGV LQ $QJROD WR GLVFHUQ SDWWHUQV WKDW PD\ UHÀHFW SK\VLFDO GULYHUV RI evolution, and that are also relevant to population structure. In modern marine ecosystems, GLVWULEXWLRQ SDWWHUQV UHÀHFWLQJ SULPDU\ SURGXFWLYLW\ DUH LQGLFDWLYH RI ERWWRP?XS FRQWURO? ,Q the fossil record, productivity-controlled distribution patterns can also be perceived. Physi- cal parameters resulting in environmental stability, sea-level change, oceanic anoxic events, paleoclimate, and paleogeography are examined in comparison with taxonomic diversity and life history patterns. Mosasaurs originated during a time of high global temperatures and shallow temperature gradients. As upper-trophic-level species of modest size and plesiopedal limb structure (capable of terrestrial locomotion), early mosasaurs were subject to both top- down and bottom up pressures. The attainment of larger size coupled with emigration and biogeographic distribution in areas of high primary productivity, and niche differentiation VKRZQ E\ 13C values, indicate bottom-up pressures. Productivity along the African coast since the formation of the Atlantic Ocean facilitated the co-occurrence of diverse marine tetrapods through time, and has culminated today in the Benguela large marine ecosystem. Just as the current Benguela ecosystem has tetrapod species populations dominated by both bottom-up (cetaceans) and top-down strategies (sea birds and pinnipeds), so too did the Cre- taceous community, with mosasaurs and plesiosaurs having predominantly bottom-up popu- lation structure, while sea turtles and pterosaurs were more subject to top-down pressures.