Aeronian
In the geologic timescale, the Aeronian is an age of the Llandovery epoch of the Silurian period of the Paleozoic era of the Phanerozoic eon that began 440.8 ± 1.2 Ma and ended 438.5 ± 1.1 Ma. The Aeronian age succeeds the Rhuddanian age and precedes the Telychian age, all in the same epoch.The GSSP is located in the Trefawr Track section, 500m north of Cwm-coed-Aeron Farm, Wales, UK. The GSSP lies within the gently-dipping blocky mudstones of the Trefawr Formation, which principally yield abundant and diverse shelly faunas, but also contain enough graptolites to allow recognition of several biozones.Palaeontology
Agnathans
Cephalopods