Protodus jexiWoodward, 1892 (Chondrichthyes), from the Lower Devonian Campbellton Formation, New Brunswick, Canada
Authors
Susan Turner
1School of Geosciences, Monash University, Clayton, Victoria 3800
2Queensland Museum (Geosciences), 122 Gerler Road, Hendra, Qld 4011
3Natural Science Department, New Brunswick Museum, 277 Douglas Avenue, Saint John, NB Canada E2K 1E5
Randall F. Miller
3Natural Science Department, New Brunswick Museum, 277 Douglas Avenue, Saint John, NB Canada E2K 1E5
Keywords:
Early gnathostomes, Early chondrichthyans, Protodus, Teeth, Early Devonian, Canada, Taxonomy, Morphology
Abstract
Protodus jexi from the early Emsian ‘Atholville beds’, Campbellton Formation between Atholville and Campbellton, northern New Brunswick, Canada, is redescribed from material studied by R. H. Traquair and new specimens. Protodus is a valid monotypic genus with rows of shark-like serrated teeth. The taxon is based solely on teeth, some of which are associated. The teeth have monocuspid crowns with a thin enameloid layer and distinctive labial depressions or grooves, and large subrectangular to D-shaped cladodont-like bases some laterally and downwards extended. Crown histology is orthodentine merging down into the osteodentine of the base. A possible relationship with cladodont-bearing sharks is mooted and Protodus and other putative late Silurian to early Devonian chondrichthyan teeth are referred to a redefined family Protodontidae WOODWARD.
