Our Valuable Paleontological Resources
Paleontological
resources (i.e., fossils) represent a direct link with past
organisms and ecosystems and as such are the primary source
of evidence about the biological history of our planet.
Fossils include the remains (such as bones, teeth, shells,
and wood) or traces (such as footprints, trackways, burrows,
and impressions) of organisms that lived during past geological
periods. For practical purposes, the temporal division between
fossils and subfossils is placed at the Pleistocene/Holocene
boundary; approximately 10,000 years before the present.
Fossils are typically buried in layered sedimentary rocks
and can be collected and studied when those rocks are exposed
at the Earth's surface. Natural exposures occur in eroding
sea cliffs, valley slopes and desert badlands. Artificial
exposures occur in graded road cuts, roadways, building pads,
utility line trenches, and basement excavations. The conditions
responsible for creating artificial exposures of sedimentary
rock layers are also responsible for destruction of paleontological
resources.
Because
paleontological resources are an important part of our natural
heritage, their destruction is considered by state and federal
directives to represent a negative environmental impact.
Fortunately, such negative impacts can be mitigated. Typical
mitigation programs include on-site monitoring of active
excavations, discovery and recovery of exposed fossils, transportation
of recovered specimens to a professional preparation/conservation
laboratory, laboratory-based preparation and curation of
recovered fossils in regional repositories/museums where
they are available for present and future generations of
citizens, students, and professional scientists.
The San
Diego Natural History Museum assumes the substantial
responsibility to maintain fossils collected by PaleoServices
staff in perpetuity for the enjoyment and education
of future generations. In addition, many salvaged fossils
are being studied by researchers both here in California
and across the country. Numerous scientific papers have
been published on these salvaged specimens.
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