List of index fossils

File:Index fossils.gif

Examples of index fossils<ref name="USGS_indexfossils">Index Fossils, from the US Geological Survey. Updated July 31, 1997.</ref>

Template:Paleontology 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

Image	Scientific Name	Geological time interval	Period (million years ago)
File:Calico scallop 02.jpg Calico scallop	Argopecten gibbus	Quaternary	1.8
	Neptunea tabulata	Quaternary	1.8
File:Viviparus glacialis - Rosmalen - Late Tiglian.jpg	Viviparus glacialis	Tiglian (Early Pleistocene)	2.3–1.8
	Calyptraphorus velatus	Tertiary
	Venericardia planicosta	Eocene
File:SmallScaphites.jpg Scaphites	Scaphites hippocrepis	Cretaceous	143.1–66
File:InoceramusCretaceousSouthDakota.jpg Inoceramus	Inoceramus labiatus	Cretaceous
File:Ammonit - Wüstenhaus.jpg Perisphinctes	Perisphinctes tiziani	Jurassic	201.3–145
	Nerinea trinodosa	Jurassic
	Tropites subbullatus	Triassic
File:Monotis fossil shells - Kiritehere beach.jpg	Monotis subcircularis	Triassic
File:Leptodus100711.jpg Leptodus	Leptodus americanus	Permian
Parafusulina	Parafusulina bosei	Permian
	Dictyoclostus americanus	Pennsylvanian
	Lophophyllidium proliferum	Pennsylvanian
	Cactocrinus multibrachiatus	Mississippian
	Prolecanites gurleyi	Mississippian
File:Mucrospirifer mucronatus Silica Shale.JPG Mucrospirifer	Mucrospirifer mucronatus	Devonian	416–359
	Palmatolepis unicornis	Devonian
	Tetragraptus fructicosus	Ordovician
File:BLW Trilobite (Paradoxides sp.).jpg	Paradoxides	Cambrian	509–500
	Billingsella corrugata	Cambrian
File:Archeocyathids.JPG	Archaocyathids	Cambrian	529–509

See also

• Biostratigraphy#Index fossils