The teeth are small and arranged in numerous files. In today's oceans, some 230 species are known to exist - most with relatively similar tooth morphologies. Scientists working with these fish continue their attempts to assign and reassign species to a genus or subgenus. The genus Raja encompasses well over a third of the known skates and has been divided into nine subgenera. The elongated male cusp is clearly evident.
Ontogeny is another variability which has gone to extremes in skates.
Younger specimens may have roots that display little or no nutrient groove, while larger specimens show fully developed grooves. Although crowns may remain somewhat similar, the roots can vary substantially from distal to mesial location. Depending on species the roots may be wider or narrower than the crown, symmetrical or asymmetrical, parallel or splayed, have a well formed nutrient groove or virtually lack one. 1817 Barndoor skate This common skate of the western North Atlantic, from North Carolina to New Foundland, is a likely candidate for representation in the Lee Creek fauna, at least the subgenus Dipturus . Referred to as the Barndoor skate, it can be found near shore in warm waters or down to the cooler waters of over 1000 feet.