List of index fossils

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Examples of index fossils Index fossils.gif
Examples of index fossils

Index fossils (also known as guide fossils or indicator fossils) are fossils used to define and identify geologic periods (or faunal stages). Index fossils must have a short vertical range, wide geographic distribution and rapid evolutionary trends. Another term, "zone fossil", is used when the fossil has all the characters stated above except wide geographical distribution; thus, they correlate the surrounding rock to a biozone rather than a specific time period.

List of index fossils in chronological order
ImageScientific NameGeological time intervalPeriod
(million years ago)
Calico scallop 02.jpg
Calico scallop

Argopecten gibbus
Quaternary 1.8
Neptunea tabulata Quaternary 1.8
Viviparus glacialis - Rosmalen - Late Tiglian.jpg Viviparus glacialis Tiglian (Early Pleistocene)2.3–1.8
Calyptraphorus velatus Tertiary
Venericardia planicosta Eocene
SmallScaphites.jpg
Scaphites
Scaphites hippocrepis Cretaceous 143.1–66
InoceramusCretaceousSouthDakota.jpg
Inoceramus
Inoceramus labiatus Cretaceous
Ammonit - Wustenhaus.jpg
Perisphinctes
Perisphinctes tiziani Jurassic 201.3–145
Nerinea trinodosa Jurassic
Tropites subbullatus Triassic
Monotis fossil shells - Kiritehere beach.jpg Monotis subcircularis Triassic
Leptodus100711.jpg
Leptodus
Leptodus americanus Permian
Parafusulina Parafusulina bosei Permian
Dictyoclostus americanus Pennsylvanian
Lophophyllidium proliferum Pennsylvanian
Cactocrinus multibrachiatus Mississippian
Prolecanites gurleyi Mississippian
Mucrospirifer mucronatus Silica Shale.JPG
Mucrospirifer
Mucrospirifer mucronatus Devonian 416–359
Palmatolepis unicornis Devonian
Tetragraptus fructicosus Ordovician
BLW Trilobite (Paradoxides sp.).jpg Paradoxides Cambrian 509–500
Billingsella corrugata Cambrian
Archeocyathids.JPG Archaocyathids Cambrian 529–509

See also

References

  1. Index Fossils, from the US Geological Survey. Updated July 31, 1997.