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XB-STAGE-4
| Name: early tailbud stage XAO ID: 1000002 Definition: "Tailbud stage that refers to the earlier events associated with this stage, comprising Nieuwkoop and Faber stages 22 to 28." |  | 
| Preceded By: tailbud stage | Succeeded By: NF stage 22 | 
Component Stages: NF stage 23, NF stage 27, NF stage 22, NF stage 24, NF stage 26, NF stage 28, NF stage 25
