2009/07/16 by Jun Liu, Bruce S. Rubidge, Jinling Li · 1 citation
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Evolution and Paleontology Studies #Ichthyology and Marine Biology
paper · pdf · doi:10.4202/app.2008.0071
openalex publication_date 2009/07/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
The distant evolutionary ancestry of mammals is documented by a rich therapsid fossil record. While sphenacodontid synapsids are considered the sister-group of therapsids, the place of origin of therapsids is an enigma, largely because of a long standing morphological and temporal gap (Olson's Gap) in their fossil record. We describe a new large predatory synapsid, Raranimus dashankouensis gen. et sp. nov., from the Middle Permian of Dashankou in China which has a unique combination of therapsid and sphenacodontid features. This specimen is of great significance as it is a basal therapsid which is the sister taxon to all other therapsids. The fact that it was found in association with Early Permian tetrapods (Anakamacops and Belebey) suggests that it is the oldest therapsid and provides the first evidence of therapsid-bearing rocks which cover Olson's Gap. It further supports that therapsids may have had a Laurasian rather than Gondwanan origin.