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This is an incomplete left palatine (upper) tooth plate from a chimaeroid fish. The length is 4 cm. The front of the mouth was to the left. Chimaeroids are fishes related to sharks. Examples of living chimaeroids are ratfishes and elephant fishes. The dentition of chimaeroids consists of 6 plates, 4 in the upper jaw and 2 in the lower, which are adapted for crushing. The spotted crushing surface, visible on this specimen, is called a tritor. Since this plate is rather worn, it is difficult to identify, even as to genus. First opinions from four different experts were that it might be Edaphodon sp., Elasmodus sp., Callorhinchus sp., or Ischyodus sp. These opinions, however, were based only on photographs. Prof. Barbara Stahl, who has actually seen the specimen, and who has literally written the book on the subject of fossil chimaeroids [Handbook of Paleoichthyology, Vol. 4, Chondrichthyes III. Holocephali, 1999] believes it to be Leptostylus sp. The overall shape is certainly very much like that of the holotype of Leptomylus densus, [Fig. 150-A of the previously mentioned book]. Leptomylus has previously been reported from the Upper Cretaceous of North America.
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