Recently added articles from Paleobiology:
Patristic evolutionary rates suggest a punctuated pattern in forelimb evolution before and after the origin of birds
Jan 01, 2009; ... Abstract.-The evolution of powered flight has traditionally been associated with the origin of birds, the most successful clade of modern tetrapode, as exemplified by the nearly 10,000 species alive today. Flight requires a suite of morphological changes to skeletal anatomy to create a light yet ...
Paleoecology of the early Eocene Willwood mammal fauna from the central Bighorn Basin, Wyoming
Jan 01, 2009; ... Abstract.-The mammal fauna of the Willwood Formation, central Bighorn Basin, Wyoming, is ideal for paleoecological analysis because it is extensive, well studied, and continuously distributed over sediments representing the first 3 Myr of the early Eocene. The geology of the Bighorn Basin is ...
The double mass extinction revisited: reassessing the severity, selectivity, and causes of the end-Guadalupian biotic crisis (Late Permian)
Jan 01, 2009; ... Abstract.-The end-Guadalupian extinction, at the end of the Middle Permian, is thought to have been one of the largest biotic crises in the Phanerozoic. Previous estimates suggest that the crisis eliminated 58% of marine invertebrate genera during the Capitanian stage and that its selectivity ...
The influence of lithification on Cenozoic marine biodiversity trends
Jan 01, 2009; ... Abstract.-Recent research has corroborated the long-held view that the diversity of genera within benthic marine communities has increased from the Paleozoic to the Cenozoic as much as three-to fourfold, after mitigating for such biasing influences as secular variation in time-averaging and ...
Functional morphology and evolution of early Paleozoic dasycladalean algae (Chlorophyta)
Jan 01, 2009; ... Abstract.-Biophysical modeling and morphologic data from the fossil record were used to investigate the functional significance of changes in thallus morphology during the early evolutionary history of dasycladalean algae (dasyclads), a clade of benthic marine macroalgae. Modeling results ...
Ecology of extreme faunal turnover of tropical American scallops
Jan 01, 2009; ... Abstract.-The marine faunas of tropical America underwent substantial evolutionary turnover in the past 3 to 4 million years in response to changing environmental conditions associated with the rise of the Isthmus of Panama, but the ecological signature of changes within major clades is still ...
Fidelity of variation in species composition and diversity partitioning by death assemblages: time-averaging transfers diversity from beta to alpha levels
Jan 01, 2009; ... Abstract.-Despite extensive paleoecological analyses of spatial and temporal turnover in species composition, the fidelity with which time-averaged death assemblages capture variation in species composition and diversity partitioning of living communities remains unexplored. Do death assemblages ...
Preservation of spatial and environmental grathents by death assemblages
Jan 01, 2009; ... Abstract.-Although only a few studies have explicitly evaluated live-dead agreement of species and community responses to environmental and spatial grathents, paleoecological analyses implicitly assume that death assemblages capture these grathents accurately. We use nine data sets from modern, ...
Revisiting Raup: exploring the influence of outcrop area on diversity in light of modern sample-standardization techniques
Jan 01, 2009; ... Abstract.-Since David Raup's seminal 1976 work, paleontologists have been aware of the relationship between outcrop area and diversity. By incorporating lithologic data derived from Alexander Ronov and coworkers into our own data on areas of mapped outcrops from worldwide geologic maps, we are ...
On the bidirectional relationship between geographic range and taxonomic duration
Oct 01, 2008; ... Abstract.- Geographic range and taxonomic duration are known to be positively correlated in a number of biologic groups; this is usually attributed to the influence of range upon duration rather than the other way about. Here we analyze two distinct components of this correlation within ...
Adjusting global extinction rates to account for taxonomic susceptibility
Oct 01, 2008; ... Abstract.- Studies of extinction in the fossil record commonly involve comparisons of taxonomic extinction rates, often expressed as the percentage of taxa (e.g., families or genera) going extinct in a time interval. Such extinction rates may be influenced by factors that do not reflect ...
Press-pulse: a general theory of mass extinction?
Oct 01, 2008; ... Abstract.- Previous discussions of mass extinction mechanisms generally focused on circumstances unique to each event. However, some have proposed that extensive volcanism combined with bolide impact may offer a general mechanism of mass extinction. To test this hypothesis we compared ...
Modeling fluid flow in Medullosa, an anatomically unusual Carboniferous seed plant
Oct 01, 2008; ... Abstract.- Medullosa stands apart from most Paleozoic seed plants in its combination of large leaf area, complex vascular structure, and extremely large water-conducting cells. To investigate the hydraulic consequences of these anatomical features and to compare them with other seed ...
Establishing a framework for archosaur cranial mechanics
Oct 01, 2008; ... Abstract.- The aim of this analysis was to establish the basic mechanical principles of simple archosaur cranial form. In particular we estimated the influence of two key archosaur innovations, the secondary palate and the antorbital fenestra, on the optimal resistance of biting-induced ...
How to find a dinosaur, and the role of synonymy in biodiversity studies
Oct 01, 2008; ... Abstract.- Taxon discovery underlies many studies in evolutionary biology, including biodiversity and conservation biology. Synonymy has been recognized as an issue, and as many as 30-60% of named species later turn out to be invalid as a result of synonymy or other errors in taxonomic ...
Stable isotope evidence for changes in dietary niche partitioning among hadrosaurian and ceratopsian dinosaurs of the Hell Creek Formation, North Dakota
Oct 01, 2008; ... Abstract.- Questions related to dinosaur behavior can be difficult to answer conclusively by using morphological studies alone. As a complement to these approaches, carbon and oxygen isotope ratios of tooth enamel can provide insight into habitat and dietary preferences of herbivorous ...
Hierarchy and the reconstruction of evolutionary trends: evidence for constraints on the evolution of body size in terrestrial caniform carnivorans (Mammalia)
Oct 01, 2008; ... Abstract.- Body mass is an important organism-level variable in mammalian biology, correlated with physiology, life history, and ecology. To analyze the dynamics of body size evolution, increases and decreases in body mass were tallied for ancestor-descendant (AD) species pairs for 519 ...
The flourishing diversity of models in theoretical morphology: from current practices to future macroevolutionary and bioenvironmental challenges
Jul 01, 2008; ... Abstract.- For decades, theoretical morphological studies of different groups of organisms have been successfully pursued in biological, paleontological, and computational contexts, often with distinct modeling approaches and research questions. A regular influx of new perspectives and ...
The Red Queen revisited: reevaluating the age selectivity of Phanerozoic marine genus extinctions
Jul 01, 2008; ... Abstract.- Extinction risk is inversely related to genus age (time since first appearance) in most intervals of the Phanerozoic marine fossil record, in apparent contradiction to the macroevolutionary Red Queen's Hypothesis, which posits that extinction risk is independent of taxon age ....
Body size, energetics, and the Ordovician restructuring of marine ecosystems
Jul 01, 2008; ... Abstract.- Major shifts in ecological dominance are one of the most conspicuous but poorly understood features of the fossil record. Here we examine one of the most prominent such shifts, the Ordovician shift from trilobite to brachiopod dominance of benthic ecosystems. Using an ...