RNames - Scheme: Ordovician time bins (Webby et al., 2004) (9)
Binning results
| Structured Name | Oldest | Youngest |
|---|---|---|
| A Ross 1968 | 1a | 1a |
| Aalenian | 5c | 6c |
| Abak | 5d | 6c |
| Abarsaj | 6a | 6c |
| Aber Mawr Shales | 4b | 4c |
| Aber-Corris | 6a | 6b |
| Abercastle | 2b | 3a |
| Abercwmeiddaw | 6a | 6b |
| Abereiddi Tuff | 4b | 4c |
| Abereiddian | 4b | 4c |
| Acanthochitina barbata | 5d | 5d |
| Acanthochitina barbata | 5d | 6a |
| Acanthochitina cancellata | 5c | 5c |
| Acanthocordylodus festus | 5c | 6a |
| Acanthodina nobilis | 6a | 6a |
| Acanthodus lineatus | 1b | 1b |
| Acanthograptus sinensis | 1c | 1d |
| Acanthograptus suecicus | 2c | 3a |
| Acodus delicatus | 1c | 1d |
| Acodus deltatus / Oneotodus costatus | 1c | 1d |