An Early Cretaceous Record of the Mawsoniid Coelacanth Axelrodichthys from Niger

Coelacanths in the Family Mawsoniidae include ten genera with a primarily Gondwanan distribution. Two of the genera—Mawsonia and Axelrodichthys—show a related biogeographic pattern of occurrences in the Cretaceous of Brazil and Africa. This report documents the presence of Axelrodichthys in the Early Cretaceous of Niger based on a partial skull roof and partial extrascapular series from the Aptian ‘Fish Mountain’ site at Ingal (or Ingall) in central western Niger. Assignment of the specimen to Axelrodichthys is based on the presence of a median extrascapular along the posterior margin of the skull roof, an element that is absent in the sister-genus Mawsonia. This record from Niger fits into the broader pattern of the genus co-occurring in both northeastern Brazil and northwestern Africa, and then subsequently expanding its range across Africa during the Cretaceous—reaching Niger at an intermediate stage—and then eventually dispersing as far east as Madagascar and as far north as what is now southern Europe by the Late Cretaceous.