Bawitius Explained

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, 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.[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. 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: 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]

Notes and References

  1. Grandstaff, B. S. Smith, J. B.. Lamanna, M. C.. Lacovara, K. J.. Abdel-Ghani, M. S. . 2012 . Bawitius, gen. nov., a giant polypterid (Osteichthyes, Actinopterygii) from the Upper Cretaceous Bahariya Formation of Egypt . Journal of Vertebrate Paleontology . 32 . 1 . 17–26 . 10.1080/02724634.2012.626823. 140547157.