High levels of mortality, primarily by snakes and ground predators, were also observed and likely contribute, along with the unpredictability of Madagascar’s climate, to the unusually fast life history of these mammals. “
“Cetaceans swim by the alternate action of their epiaxial and hypaxial

muscles and their propulsive movements are confined to the vertical plane. Changes in the shape and mechanical Palbociclib manufacturer properties of vertebrae strongly affect their function during oscillatory swimming. The first objective of this study was to provide a quantitative characterization of vertebral morphology in representatives of the Delphinidae and Pontoporiidae families. A novel morphometric approach was applied, using nine vertebral measurements and three indices. The second objective was to assess the relationship

between morphology and both habitat and size through regression analyses. The phylogenetic PF-01367338 cost structure of the distribution of characters was also explored by estimating phylogenetic signal. No relationship was found between morphology and habitat or size, but vertebral measurements and indices showed a significant phylogenetic signal. Morphological profiles indicated that coastal and oceanic delphinid species had a conservative regionalization of the vertebral column. All delphinid species showed discoidal centra morphology, while Pontoporia blainvillei presented a spool-shaped morphology. Differences in vertebral morphology and inferred muscular architecture between P. blainvillei and delphinids could indicate distinct dynamics of vertebral movement during swimming. However, other complex and specific functional relationships and life-history traits may also be influencing vertebral morphology. The detailed

study of the complex evolutionary history of lineages could bring to light other clarifying dimensions for understanding morphological evolution in odontocetes. “
“Trilobites comprise a major group Paclitaxel in vivo of extinct marine arthropods, which thrived in a variety of habitats surrounding the Palaeozoic palaeocontinents. The evidence that can be used to infer their ecology is reviewed, including functional anatomy, field occurrence and geology in comparison with living arthropods and palaeogeography. Where different lines of evidence are consistent with one interpretation, the inferred life habits are considered well supported, but there remain some intriguing enigmas. Trilobites occupied many of the ecological niches available to living marine arthropods, including the pelagic realm. Benthic species included predator/scavengers, grazers and particle feeders, and specialist filter feeders.