List 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 have all the characters stated above except wide geographical distribution, they are limited to a zone and can't be used for correlations of stratas. [1]

FossilScientific NameTime PeriodMillion Years Ago
Calico scallop 02.jpg
Calico Scallop
Pecten gibbus
Argopecten gibbus
Quaternary Period1.8 million years ago
Neptunea tabulataQuaternary Period1.8 million years ago
Viviparus glacialis - Rosmalen - Late Tiglian.jpgViviparus glacialisTiglian (Early Pleistocene)0.5 million years ago
Calyptraphorus velatusTertiary Period
Venericardia planicostaEocene
SmallScaphites.jpg
Scaphites
Scaphites hippocrepisCretaceous Period145 to 66 million years ago
InoceramusCretaceousSouthDakota.jpg
Inoceramus
Inoceramus labiatusCretaceous Period
Ammonit - Wüstenhaus.jpg
Perisphinctes
Perisphinctes tizianiJurassic Period201.3 to 145 million years ago
Nerinea trinodosaJurassic Period
Tropites subbullatusTriassic Period145 to xxx million years ago
Monotis subcircularisTriassic Period
Leptodus100711.jpg
Leptodus
Leptodus americanusPermian Periodxxx to xxx million years ago
ParafusulinaParafusulina boseiPermian Period
Dictyoclostus americanusPennsylvanian Periodxxx to xxx million years ago
Lophophyllidium proliferumPennsylvanian Period
Cactocrinus multibrachiatusMississippian Periodxxx to 416 million years ago
Prolecanites gurleyiMississippian Period
Mucrospirifer mucronatus Silica Shale.JPG
Mucrospirifer
Mucrospirifer mucronatusDevonian Period416 to 359 million years ago
Palmatolepis unicornisDevonian Period
Silurian Period359 to xxx million years ago
Tetragraptus fructicosusOrdovician Periodxxx to 509 million years ago
BLW Trilobite (Paradoxides sp.).jpgParadoxidesCambrian Period509 to 500 million years ago
Billingselia corrugataCambrian Period
Archeocyathids.JPGArchaocyathidsLower Cambrian529 to 509 million years ago
Examples of index fossils
  • references

References

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