Fossilization 186 INDEX

The ideal conditions for the formation of fossils occur in areas of rapid sedimentation, especially those parts of the seabed that lie below the zone of wave disturbance. See also CHEMICAL fossil INDEX FOSSIL MICROFOSSn. 

O Brien, M. J. and R. L. Lyman (1999), Seriation, Stratigraphy, and Index Fossils The Backbone of Archaeological Dating, Kluwer Academic/Plenum, New York. 

U.S. DOE, Enhanced Oil Recovery/C02 Injection, http //www.fossil.energy.gov/programs/oilgas/eor/ index.html, 2007. 

Method. Whether to use stomatal density or stomatal index from leaf fossils for paleoelevation reconstruction depends on the availability of modern reference material and the quality of the fossil cuticle. Ideally both should be used on the same material to increase the confidence in the provided estimates. In cases, however, when the quality of the fossil cuticle does not allow epidermal cells to be recognized with the necessary accuracy, and stomatal index can not be determined, stomatal density measurements are the only available option. To use stomatal index, a training set of modem and herbarium material grown under different C02 pressure provides the necessary calibration. Because stomatal density is influenced by more factors than just the C02 partial pressure, the actual response of stomatal density of the chosen fossil taxon has to be confirmed by analyzing leaves from actual elevation transects. Stomatal density is physiologically more informative than stomatal index as SD is strongly related to maximum stomatal conductance. 

Taxa. Although many species show the classic inverse relationship between stomatal frequency and C02, not all species do so. Therefore, the sensitivity of the species of fossil leaves needs to be tested when selecting fossil species to work with. Moreover, since plants have morphological and physiological constraints that do not allow adjustment of stomatal numbers to infinitely high or low C02, plant species have species-specific response limits to C02 (Kiirschner et al. 1997). For instance, the nonlinearity of the stomatal index-elevation... 

Stomatal density and index show great potential for paleoelevation reconstructions with low error margins, if additional error sources such as the presence of sun and shade morphotypes and especially uncertainty in sea-level C02 concentrations can be well constrained. Unlike other paleobotanical methods, stomatal frequency analysis is not restricted to angiosperm dominated floras, and has no requirements for a minimum amount of taxa present. The method will be most reliable when applied to fossil taxa that are closely related to extant species, and suitable taxa are most likely to be found for periods when C02 concentrations were not much higher than ambient (380 ppmV). 

McElwain JC, Chaloner WG (1995) Stomatal density and index of fossil plants track atmospheric carbon dioxide... 

McElwain JC, Mitchell FJG, Jones MB (1995) Relationship of stomatal density and index of Salix cinerea to atmospheric carbon dioxide concentrations in the Holocene. The Holocene 5 216-219 McElwain JC, Wade-Murphy J, Hesselbo SP (2005) Changes in carbon dioxide during an oceanic anoxic event linked to intrusion into Gondwana coals. Nature 435 479-482 Meyer HW (1992) Lapse rates and other variables applied to estimating paleoaltitudes from fossil floras. Palaeogeogr Palaeoclimatol Palaeoecol 99 71-99... 

Roth-Nebelsick A, Utescher T, Mosbmgger V, Diester-Haass L, Walther H (2004) Changes in atmospheric C02 concentrations and climate from the hale Eocene to Early Miocene palaeobotanical reconstruction based on fossil floras from Saxony, Germany. Palaeogeogr Palaeoclimatol Palaeoecol 205 43-67 Royer DL (2001) Stomatal density and stomatal index as indicators of paleoatmospheric C02 concentration. Rev Palaeobot Palyno 114 1-28... 

Collect modern reference material from different light intensity regimes (sun and shade leaves) and check for the possibility to recognize and separate these (for instance through cell wall undulation index (Ktirschner 1997). Often, sun-morphotypes are preferentially preserved in the fossil record. If sun and shade leaves can be separated, develop morphotype-specific calibration curves to minimize potential error. 

Analyze stomatal density and/or stomatal index on fossil material, (abaxial and/or adaxial). For processing methods, see Kouwenberg et al. 2007. 

Is the fossil load factor the same as the renewability index Are they related metrics ... 

The mixture of PAHs present in a particular sample in many cases mirrors the sources that produce them. Several methods can be used to qualitatively identify the probable sources of PAHs. Commonly used methods include the abundance ratios of individual compounds, the fossil fuel pollution index (FFPI), and diagnostic ratios indicative of sources (petrogenic vs. pyrogenic). Quantitative apportionment of sources needs sophisticated statistical approaches such as the chemical mass balance models (Li et al., 2003). 

Apart from the above taxa, Nehring (1898) described from one of the three localities Dolomys milleri Nehring, an index fossil of Beremend-aged faunas to this day. 

Fig. 8. Dentition of the most important index fossil of the Lower Pleistocene, Mimomys plicocaenicus Forsyth-Major.

Fig. 13. Characteristic index fossil of the older phases of the Middle Pleistocene, the vole Mimomys savini Hinton, (a) and (b) Occlusal surface of the first molar of a young and an adult specimen (c) and (d) same from lateral view occlusal surface of (e) M2 (f) M2 and (g) M] (upper first molar). Characteristic from lateral view is the weak development of roots. Locality rock shelter of Tarkd.

The crested Porcupine Hystrix), as an index fossil , substantiates the allocation of two more faunal assemblages of lesser importance to the Varboian stage. One of these is from the Biikk Mountains. A collection of a few bones was found in old collections of the Department of Palaeontology of the Hungarian Natural History Museum. According to the specimen labels, the bones were collected in 1936 by... 

Figure 2 Seasonal and long-term trends in concentrations, and 5 0 values of atmospheric CO2 measured at high latitudes in the northern (Barrow, Alaska) and southern (American Samoa) hemispheres by the NOAA/CMDL-CU flask network (www.cmdl.noaa.gov/ccgg/index.html). The terrestrial biosphere, concentrated in the northern hemisphere, dominants the seasonal cycle. Fossil fuel emission dominates the long-term trends in CO2 and in...

McIntyre A. (1970) Gephyrocapsa protohuxleyi sp. n. as possible phyletic link and index fossil for the Pleistocene. Deep-Sea Res. 17, 187—190. 

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