Page 54 - Introduction to Paleobiology and The Fossil Record

FOSSILS IN TIME AND SPACE 41

from our stratigraphic charts in the near is, local or regional) species that have restricted
future. ranges in contrast to the more widespread
cosmopolitan (worldwide) species. Continen-
tal configurations and positions have changed

PALEOBIOGEOGRAPHY
through time, as have faunal and fl oral prov-
No man is an island, entire of itself; inces. Nevertheless, paleontological data were
every man is a piece of the continent, instrumental in demonstrating the drift of the
a part of the main. wandering continents; the fit of the outlines

If a clod be washed away by the sea, of Africa, South America, India, Antarctica
Europe is the less, and Australia (Fig. 2.14) was clearly not a
as well as if a promontory were, coincidence, nor was the matching of rocks
as well as if a manor of thy friend’s or of and fossils among these continents. In the
thine own were.
John Dunne (1624) Meditation
maximum likelihood

subzone scaling
All living organisms have a defi ned geographic Scaled composite Cubic spline fitting and
range; the ranges may be large or small, and Orbital tuning Seafloor spreading Direct dating Detailed direct Proportional error estimation
controlled by a variety of factors including dating standard
climate and latitude. By the middle of the 0 Cenozoic
1800s both Charles Darwin (1809–1882) and
Alfred Russel Wallace (1823–1913) had rec- 90 Cretaceous
ognized the reality of biogeographic provinces 180 Jurassic
in their respective studies on the Galápagos Time (Ma) Triassic
islands and in the East Indies. The Earth today 270 Permian
can be divided into six main provinces (Nearc- 360 Carboniferous
tic, Palearctic, Neotropical, Ethiopian, Orien- Devonian
Silurian
tal and Australasian) based on the perceptive 450 Ordovician
work of Philip Sclater and Alfred Russel 540 Cambrian
Wallace in the later 1800s.
Discrete biogeographic units are, however, Figure 2.13 The various methods currently
defined by faunal and fl oral barriers. Prov- available to construct the geologic time scale

inces are characterized by their endemic (that 2004 (GTS2004).

Box 2.5 The Chronos initiative

There are a number of different geological time scales, developed by different groups of authors for
different intervals of geological time, and many different ways to analyze time series data of this
type. The Chronos (Greek for time) project is a web-based initiative that seeks to centralize all the
various time scales and analytic tools through one web portal. This is a chronometric rather than
chronostratigraphic system and thus deals with radiometric age rather than the relative order of
events. Thus software is available to create your own geological time scale and to compare data
from existing published sources. These facilities, together with the opportunities to build your own
range charts and effect high-resolution correlation of strata, open many exciting opportunities. Real
advances are now possible in dating the precise timing and rates of biological processes such as
extinction and recovery rates together with the accurate timing of the origins of higher taxa and the
velocity of morphological change along evolving lineages.
The site can be accessed through http://www.blackwellpublishing.com/paleobiology/.