Microscopy of thin fossil section purchased from SDFossils, UK-based company based on ebay, Sept 2017:
By Andrew Thornett
Odontaspis vincenti tooth.
This specimen came from the Eocene age phosphate mines of Morocco.
From Wikipedia: Odontaspis is a genus of sand shark with two extant species.Odontaspis species can reach a length of about 3.6 metres (12 ft). Currently living versions (extant species) are large-bodied sharks with long, conical snouts, broad-based dorsal and anal fins, and an asymmetrical caudal fin with a strong lower lobe. Their teeth are large, with prominent narrow cusps.They are distinguished from the similar genus Carcharias by the absence of crushing posterior teeth.These bottom dwelling, deepwater sharks can be found in temperate and tropical waters of all the oceans.
Wikipedia also lists three extinct species: Odontaspis aculeatus Capetta & Case, 1975, Odontaspis speyeri (Dartevelle & Casier, 1943), Odontaspis winkleri Leriche, 1905. Wikipedia does not list Odontaspis vincenti – however the Museum National D’Histoire Naturelle registers on its website three exogenous rock specimens from this species, and a number of fossil suppliers are marketing teeth from this species – I guess this might be due to the large Moroccan find from which my sample comes.
The fossil thin section provided me today with the opportunity to compare the structure of the fossilised tooth with that of teeth from currently living sharks. In practice, obtaining microscope images from Google from sharks turned out to be very difficult (I couldn’t find any!) so I present below some photos from other living animals.
My images of O vincenti fossilised tooth thin section with Zeiss IM microscope today (Bresser MikrOkular camera):
Pictures of O vincenti fossilised tooth:
Pictures of modern teeth histology:
Comparing above to one of my photos (x4) of the fossilised tooth:
The above picture is analogous to the first diagram above it showing pulp, odontoblasts, dentin, enamel – demonstrating that fossilised teeth show similar structure at microscopic levels to modern teeth.