Peculiar tooth renewal in a Jurassic ray-finned fish (Lepisosteiformes, dagger Scheenstia sp.)

Leuzinger, Lea; Cavin, Lionel; Lopez-Arbarello, Adriana und Billon-Bruyat, Jean-Paul (2019): Peculiar tooth renewal in a Jurassic ray-finned fish (Lepisosteiformes, dagger Scheenstia sp.). In: Palaeontology, Bd. 63, Nr. 1: S. 117-129

Abstract

Tooth replacement in vertebrates is extremely diverse, and its study in extinct taxa gives insights into the evolution of the different dental renewal modes. Based on mu-CT scans of a left lower jaw of the extinct fish dagger Scheenstia (Actinopterygii, Lepisosteiformes), we describe in detail a peculiar tooth replacement mode that is, as far as we could ascertain from the literature, unique among vertebrates. The formation of the replacement teeth comprises a 180 degrees rotation of their acrodin cap that occurs intraosseously within bony crypts, and their setting up appears to be synchronous. We propose a model for the dental renewal process and identify complementary anatomical features visible in the tomography such as the junction between the different tooth-bearing bones (prearticular-coronoid and dentary), as well as cavities corresponding to intraosseous crypts, nervous and/or vascular canals. The location of the cavities and their subsequent identification (e.g. Meckel's cavity, mandibular sensory canal) help us to identify the function of pores visible on the bone surface and understand their relation to internal anatomical features. Finally, recognition of this tooth replacement mode raises the question of whether it is specific to dagger Scheenstia or related to a particular dentition type and thus potentially occurs in other lineages.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0031-0239
• Sprache: Englisch