Analysis of tail morphology and osteology in Ethiopian indigenous sheep

•The external tail morphology combined with a detailed tail osteological analysis.•Tail morphological and osteological traits allow to differentiate Ethiopian sheep.•Multivariate analyzes categorize the studied sheep into four distinct tail morphotypes.•Distinction between thin- and fat-tail sheep support a genetic control of fat depot.•Phenotypic baselines for genome mapping and archeozoological studies generated.