Bawitius

{{Short description|Extinct genus of fishes}}

{{Speciesbox

| fossil_range = Late Cretaceous, {{Fossil range|99.7|94.3}}

| image = Bawitius restoration.png

| image_caption = Restoration of Bawitius

| genus = Bawitius

| parent_authority = Grandstaff et al. 2012

| species = bartheli

| authority = Grandstaff et al. 2012, (Schaal, 1984)

| synonyms =

  • Polypterus bartheli Schaal, 1984Schaal, S. (1984). Oberkretazische Osteichthyes (Knochenfische) aus dem Bereich von Bahariya und Kharge, Ägypten, und ihre Aussagen zur Palökologie und Stratigraphie. Berliner Geowissenschaftliche Abhandlungen Reihe A, 53: 1–76.

}}

Bawitius is an extinct genus of giant polypterid from the Upper Cretaceous (lower Cenomanian) Bahariya Formation of Egypt.{{Cite journal|author=Grandstaff, B. S|author2=Smith, J. B.|author3=Lamanna, M. C.|author4=Lacovara, K. J.|author5=Abdel-Ghani, M. S. |year=2012 |title=Bawitius, gen. nov., a giant polypterid (Osteichthyes, Actinopterygii) from the Upper Cretaceous Bahariya Formation of Egypt |journal=Journal of Vertebrate Paleontology |volume=32 |issue=1 |pages=17–26 |doi=10.1080/02724634.2012.626823|s2cid=140547157|url=https://www.researchgate.net/publication/233291244}} 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. It is known from the holotype TU-B SFB 69 Vb 003 (= Bah 5/12-016): left ectopterygoid scales and some sparse scales.

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.

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.

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.

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.

References