Many modern paleobiological analyses are conducted at the generic level, a practice predicated on validity of genera as meaningful proxies for species. Uncritical application in such analyses, however, has led—perhaps inadvertently—to unjustified reification an evolutionary context. While utility species studies should be evaluated empirical issue, it is increasingly assumed (rather than demonstrated) that suitable This problematic both ontological and epistemological grounds. Genera...

Oxygen and carbon isotopic profiles across the shells of well-preserved bivalves gastropods from Pliocene Pinecrest Beds near Sarasota, Florida, provide detailed records paleoen-vironmental paleoclimatic conditions under which these high-density shell beds accumulated, as well offer insight into shell-growth rates longevity. Eight turritellid were analyzed within surrounding two Turritella-rich beds, an upper bed unit 2(2.5-2.0 Ma) a lower situated top main bed, 6/7(3.5-2.5 Ma). Three plus...

About 70 percent of tropical western Atlantic mollusk species have become extinct since the Pliocene, which has led to perceptions a corresponding decline in diversity. However, compilation gastropod from Plio-Pleistocene faunas United States coastal plain and Recent indicates that regional diversity not changed Pliocene. Gastropod Pliocene Pinecrest Beds Florida approximates seen today on either coast Florida. is demonstrably different than eastern Pacific. High extinction rates must been...

ABSTRACT Abundance and distribution of frogs inhabiting the litter layer an area primary lowland rain forest in Central Amazonia were studied over a period 15 months by sampling 498 plots each 5m × 5m. The frog fauna consists 23 species, but only 12 these encountered plots, 84% belonged to six species. Total abundance diversity within plot data are strongly seasonal peak late wet season. Both positively correlated with volume moisture. Most this variation is due seasonality reproduction, as...

A new review of available information, published and unpublished, on the biology paleobiology turhtelline gastropods expands our knowledge this important group, which is among most abundant widespread marine gastropod clades past 130 million years. It also highlights many areas in additional research needed.Living turhtellines are mainly sessile, semi-infaunal suspension feeders, shallow waters full-marine salinity temperatures below 20°C, but they can occasionally be more active diverse...

We review and synthesize multiple biotic abiotic proxies for marine nutrient food availability, primary productivity, quality (stoichiometry) propose what their relationships may have been to macroevolutionary processes, especially speciation. This confirms earlier suggestions that there has an overall increase in productivity over the Phanerozoic, but indicates irregular present levels not be peak. integrate these indicators into a new estimate of relative global ocean through Phanerozoic....

This analysis examines the evolution of greater diversity species with non-planktonic larval types relative to planktonic in turritellid gastropods. sort trend has been documented both fossil and recent biota several gastropod families. Two mechanisms for generating gradients have proposed literature. The first, selection, focuses on population biology types. second proposes that factors development are mediated by organismal adaptation responsible. Turritellids cited as a classic example...

Evidence from vertebrate and invertebrate fossil assemblages isotopic analyses supports the hypothesis that during Pliocene biological productivity in eastern Gulf of Mexico was considerably higher than Pleistocene Recent. Late faunal changes Gulf, Western Atlantic, possibly elsewhere may have resulted, at least part, this shift conditions. Even if marine temperatures declined, paleontological data appear to require a change Pliocene. This putative decline been caused by some combination...

The causes of non-acceptance evolution are groupable into five categories: inadequate understanding the empirical evidence and content modern evolutionary theory, nature science, religion, various psychological factors, political social factors. This multiplicity is not sufficiently appreciated by many scientists, educators, journalists, widespread rejection a much more complicated problem than these front-line practitioners think it is. Solutions to must therefore involve just further...

ABSTRACT The value of museum natural history collections is commonly poorly explained to, and therefore misunderstood by, the general public. This an increasingly dangerous situation at a time tight fiscal constraints; if are to survive, those charged with their care will have do more broadcast as both resources for research public education. Research values include documenting biotas no longer available present past biogeographic distributions, housing type, voucher specimens, (perhaps most...

The «Pinecrest Sand,» an abundantly fossiliferous Late Pliocene deposit best exposed near Sarasota, Florida, is a poorly understood stratigraphic unit of considerable paleobiological interest because its geographic and temporal position extremely abundant diverse mollusk fauna. absolute age this has been subject some debate, implications for taphonomic history. Evaluation published unpublished data indicates that the Pinecrest at Sarasota spans more than one million years, lower beds having...

Edward J. Petuch, 2004, CRC Press, Boca Raton, 308 p. (Hardcover, US $189.95) ISBN: 0-8493-1632-4. After a political year frequently dominated by conversations about absolutes versus nuance, it is perhaps appropriate to reflect on the sometimes paradoxical nature of our own field with respect these same distinctions. Science committed notion that there an objective truth out in physical world, and we can best approach reference world. At least introspective moments, however, scientists also...

Modern marine carbonate sediments accumulate where carbonate‐producing organisms are abundant and siliciclastic input is low. Such accumulations occur today in two main environments may be characterized as warm, low‐nutrient (WLN; also known tropical or chlorozoan) carbonates cool, high‐nutrient (CHN; cool‐water, temperate, nontropical, foramol, heterozoan) carbonates. Few form (WHN) conditions because such very rare. WLN mainly low latitudes, nutrients from upwelling terrestrial runoff CHN...