Telychian

EtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionFAD of the graptoliteSpirograptus guerichiLower boundary GSSPEl Pintado section, Seville, Spain
37°59′07″N5°55′43″W / 37.9853°N 5.9285°W / 37.9853; -5.9285Lower GSSP ratified2024Upper boundary definitionImprecise. Currently placed between acritarch biozone 5 and of Pterospathodus amorphognathoides. See Llandovery for more info.Upper boundary definition candidatesA conodont boundary (Ireviken datum 2) which is close to the murchisoni graptolite biozone.Upper boundary GSSP candidate section(s)NoneUpper boundary GSSPHughley Brook, Apedale, UK
52°34′52″N2°38′20″W / 52.5811°N 2.6389°W / 52.5811; -2.6389Upper GSSP ratified1980

In the geologic timescale, the Telychian is the third and final age of the Llandovery Epoch of the SilurianPeriod of the PaleozoicEra of the PhanerozoicEon. The Telychian Age was between 438.6 ± 1.0 million years ago (Ma) and 432.9 ± 1.2 Ma. The Telychian Age succeeds the Aeronian Age and precedes the Sheinwoodian Age. The name of the interval is derived from the Pen-lan-Telych Farm near Llandovery, Powys, Wales.

It ended with the Ireviken event.