Bawitius Temporal range: Late Cretaceous, 99.7–94.3  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Restoration of Bawitius
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Polypteriformes
Family:	Polypteridae
Genus:	† Bawitius Grandstaff et al. 2012 [1]
Species:	†B. bartheli
Binomial name
†Bawitius bartheli Grandstaff et al. 2012, [1] (Schaal, 1984 [2])
Synonyms
Polypterus bartheli Schaal, 1984 [2]

Bawitius is an extinct genus of giant polypterid from the Upper Cretaceous (lower Cenomanian) Bahariya Formation of Egypt. ^[1] The type species is B. bartheli, named as a species of Polypterus in 1984, ^[2] and the genus etymology comes from Bawiti, the principal settlement of the Bahariya Oasis in Egypt. ^[1] It is known from the holotype TU-B SFB 69 Vb 003 (= Bah 5/12-016): left ectopterygoid scales and some sparse scales. ^{[2] [1]}

Morphology

Compared to modern polypterids, Bawitius was enormous: the Bawitius holotype ectopterygoid is five times larger than the one of Polypterus and the scales are unusually large, too: these remains suggest the living animal may have been up to 300 centimeters (9.8 feet) in length. ^[1]

The morphology of Bawitius is different enough to justify its assignment to a new genus apart from Polypterus. ^[2] Unique features of the genus are, for example, an anterioposteriorly elongated contact between the lateral process and the maxilla, a high, narrow ectopterygoid and the presence of 14 teeth in the main tooth row. ^[1]

The scales are different, too, apart from size, from those of modern polypterids: ^[2] they feature a discontinuous ganoine layer, a rectilinear shape, and small articular processes. ^[1]

Ecological relevance

The existence of drastically different polypterids such as Bawitius and Serenoichthys corroborates the existence of a variety of polypterid fishes in the ecosystems of Late Cretaceous of North Africa and Brazil. ^[1]

References