About the Authors

Anne S. Schulp

Affiliation Natuurhistorisch Museum Maastricht, Maastricht, The Netherlands

Mohammed Al-Wosabi

Affiliation Department of Geology, Sana'a University, Sana'a, Republic of Yemen

Nancy J. Stevens


Affiliation Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: NS AS. Contributed reagents/materials/analysis tools: NS AS MA. Wrote the paper: NS AS. Other: Participated in research and coordinated field logistics: MA.