About the Authors

Jens Lorenz Franzen

jfranzen@senckenberg.de

Affiliations Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany, Department Geowissenschaften, Naturhistorisches Museum Basel, Basel, Switzerland

Christine Aurich

Affiliation Department Universitätsklinik für Kleintiere und Pferde, Veterinärmedizinische Universität Wien, Wien, Austria

Jörg Habersetzer

Affiliation Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: JLF CA JH. Contributed reagents/materials/analysis tools: JH. Wrote the paper: JLF. Embryology of extant horses: CA. Performance of illustrations: JH.