Transcript A brief HISTORY OF PALEONTOLOGY

A brief
HISTORY OF PALEONTOLOGY
GEOL 3213
PRE-1750: PRE-SCIENTIFIC PERIOD
• Aristotle a few hundred years B.C.
– Founder of the science of biology
– Originated the “type” concept
– Believed in the immutability of species
– Made a crude hierarchical classification of organisms
– Wrote about genera and species
• Noahan flood (for some people) accounted for fossils
& extinctions
• Dark Ages: 5th century to about 14th century
– Scientific explanations of the natural world considered
unacceptable because of church opposition and political power
• "Magical interpretations"
• "Plastic forces“
• “Devil’s doings”
• Some correct interpretations of fossils and strata
– Leonardo Da Vinci
1750-1850: EARLY SCIENTIFIC PERIOD
• Linne's classification (revolutionized biology in mid-1700's)
– Followed Aristotle’s type concept, improved on his hierarchical
classification scheme, & used genus & species
• Fossils became recognized correctly more often than before
• Practical concepts & applications being discovered by pioneers
– Principles (Hutton) & 1st geol textbook (Lyell)
– Correlation & age dating (Wm. Smith & others)
– Paleoenvironmental interpretations (d’Orbigny & others)
– Geologic time scale (Sedgwick, Murchison, etc.)
– Earth history (= Historical geology developed, many workers)
• Debates & controversies
– Evolution versus Catastrophism & Special Creation
– Cuvier vs. Lamarck
• Beginnings of paleobotany, vertebrate paleontology, invertebrate
paleontology, micropaleontology, paleoecology
• Descriptive phase dominant
1850-1900: MIDDLE SCIENTIFIC PERIOD
• Darwin's theory of evolution (early 1850's + 1858 & 1859) shook
biology by its roots. Concept of natural selection caused a
scientific revolution. Not enough fossils known to support him.
• More fossils became better known
– Vertebrate
– Invertebrate
– Microfossils (dating aquifers from well cuttings, Vienna, 1877)
– Plants
– 1st paleontology textbook
• Evolution was becoming better documented with fossils
• Descriptive phase continued to dominate work
• Generalizations or principles were being developed
1900 to Mid 20th Century
• Genetic theory developed in biology
– From the turn of the century
– Mendel's laws (1865) rediscovered
• Biological interest in fossils increased
• Evolutionary histories of invertebrate fossils documented
• Evolutionary concepts evaluated more with vertebrate fossils
• Practical applications of paleontology to resource exploration
• Micropaleontology matured early in century with Foraminifera
– Udden (1911), Augustina College, Illinois, correlated aquifers
with microfossils
– Udden, Texas Bur. Econ. Geol., used microfossils to find
Petroleum
– Many other workers followed his lead worldwide
• Faunal descriptions and documenting new species still dominant
Mid-1900's to 2002: MODERN PERIOD
• New & more sophisticated practical applications of paleontology
• Much more emphasis on principles of paleontology (many new
textbooks)
• Greater biological interest in fossils (Paleobiology)
• Ichnology expanded and developed as a subdiscipline
• Paleoecology matured as a subdiscipline
• Greater evolutionary interest in fossils (punctuated equilibrium
theory of Elldredge & Gould, cladistic analysis of Hennig)
• Literary explosion
• Micropaleontology diversified (ostracodes, diatoms, pollen,
dinoflagellates, etc., not just forams )
• Popular paleontology boomed
– Hobyists = collectors, amateurs
– Media sensationalism
• Vertebrate emphasis, especially dinosaurs
• Asteroid impacts and extraterrestrial causes of extinctions
• Declining # of professional paleontologists - inspite of popularity.
Epilogue: CONTEMPORARY PALEONTOLOGY
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1) Emphasizes less memorization (Really!)
2) More general biology, soft anatomy, & ecology emphasized
3) Is more hypothesis, problem solving, & principles oriented
4) Developing more interdisciplinary & quantitative studies
5) Taxonomy still considered fundamental
– Documents diversity and evolution of life, etc...
– Represents
• Evolving concepts of evolutionary pathways
• Reflects & guides philosophical approaches to classification
– Value of any fossil (in any application)
• Directly proportional to the quality of identification, location, age, etc.
• Poorly identified fossils result in inaccurate or erroneous applications,
conclusions…
• 6) Well located fossils (geography & stratigraphy) important to
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Age-dating & correlations
Paleoecology & paleoenvironmental studies
Evolutionary studies
Other practical applications
CONTEMPORARY PALEONTOLOGY
• 7) Three main, interrelated fronts:
– Paleobiology & evolution
– Paleoenvironments (strata) & paleoecology (organisms)
– Biostratigraphy (age of fossils & enclosing strata)
• 8) Interdisciplinary (more in some subdisciplines)
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Vertebrate paleontology is more zoological
(in Bio Depts)
Paleobotany is more botanical
(in Bot or Bio Depts)
Invertebrate paleontology is more geological
(in Geo Depts)
Micropaleontology is more geological
(in Geo Depts)
Invertebrate and Micropaleontology are more applied, need more
geological information, & stress the biology less.
– Biology & botany stress nonmarine organisms
– But most fossils are found in marine sedimentary rocks, so that there is a
strong oceanographic orientation
CONTEMPORARY PALEONTOLOGY
• Examples of multidisciplinary studies
– Geochemical studies of isotopes & trace elements in skeletons,
especially calcareous Foraminifera
– Sophistocated mathematical analysis of fossil data
• Multivariate statistics
• Cluster and factor analyses
• Numerical taxonomy replaced by cladistic analysis
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Skeletal mineralogy and microstructures
Functional morphological studies
Paleobiogeography and plate tectonics
Paleoclimatological studies
Sedimentary basin analysis
• Facies & paleoenvironments
• Correlation & age determination
• Thermal maturation studies in HC exploration (conodonts)
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