Tritor vascular tubules in a holocephalan tooth plate (Ischyodus sp.) from the Cretaceous of Mississippi, USA

A fossil chimaeroid tooth plate (Ischyodus sp.) from the Cretaceous of Frankstown, Mississippi shows exceptional preservation of tritor microstructure. Diagenetic loss of the petrodentine/whitlockin in this specimen has revealed the ultrastructure of the vascular tubule networks of tritor interior structure. The observation that vascular tubes running through the hard tissues of chimaeroid tritors host odontoblast cells supports the hypothesis of an odontoblastic origin for chimaeroid tritor tissue.