The Sayimys negevensis rodent has been extinct for some 18 million years. But the distant forerunner of the present-day gundi only got its name, and species classification, in the last few weeks.
Thanks to a handful of tiny teeth found in Israel’s Negev Desert, an international team of researchers succeeded to describe a new species of rodent even though it has been extinct for millions of years.
The new-found species has unique features that offer fresh insight into the migration patterns of ancient animals from Asia to Africa in the Early Miocene (23 million to 16 million years ago) and highlights Israel’s special paleogeographic position as the lynch-pin of the Levantine corridor connecting Eurasia with North Africa.
“It is a pivotal species that bridges the gap between an array of primitive Ctenodactylines and the most derived, Early Miocene and later, gundis,” researchers write in an article, published in the scientific journal PLoS ONE. The present-day gundi is a small rodent with comb-like bristles on the two middle toes of its hind feet, also known as comb-rat.
Gundis are the last descendants of the family Ctenodactylidae whose earliest ancestors appeared in Asia about 40 million years ago. They experienced their greatest diversification and widest distribution, from Far East to Africa, in Miocene time. Nowadays, they live in groups on rocky outcrops in deserts and semi-deserts of East and North Africa.
The Sayimys negevensis got its name from the Negev locale where it was found. Israel is the only place along the Eastern Mediterranean – stretching from Anatolia to the Sinai – where fossil sites of the Early Miocene have been found.
“The fossil sites of Israel are in a unique position to offer data on the early times of the large waves of faunal exchanges that took place around 19 million years ago between Eurasia and Africa,” said Dr. Raquel Lopez-Antoñanzas, a senior researcher at the University of Bristol, who led the research.
“The new Israeli species is closer in morphology to nearly coeval species found in Pakistan, therefore demonstrating that mammals were already using the Levantine corridor to travel between Eurasia and Africa in the Early Miocene,” said research co-author Dr. Rivka Rabinovich from the Institute of Earth Sciences and the National Natural History Collections at the Hebrew University of Jerusalem.
The discovery of the new rodent is part an international focusing on the Early Miocene fauna of Israel and its paleogeographic implications, led by Rabinovich, Dr. Rani Calvo of the Israel Geological Survey and Dr. Ari Grossman of Midwestern University in Glendale Arizona, together with other international experts, including López-Antoñanzas, Dr. Fabien Knoll of the University of Manchester and Dr. Gideon Hartmann from the University of Connecticut.