Re-investigation of enigmatic fish bones known as colobodontid/perleidid toothplates from the Upper Triassic Chinle Group (southwestern U.S.A.)

摘要: A representative selection of enigmatic denticulate/dentigerous plates from the Chinle Group previously assigned to Colobodontidae or Perleididae (“Perleidiformes”: Actinopterygii) were reinvestigated and compared purportedly similar remains diverse provenance known identity. The histology these isolated elements fragments was also investigated re-evaluate former identifications tooth-like are other Permo-Triassic fish groups. None fossils studied can be positively identified as a (crushing) toothplate colobodontid perleidid. Instead, our preliminary morpho-histologic investigation suggests that majority do not represent toothplates – despite denticles’ striking similarity with crushing teeth. Most denticulate dermal bone unique belonging as-yet unidentified osteichthyans. purported “molariform teeth” Upper Triassic American Southwest therefore interpreted multiple series denticles there is no evidence in strata “colobodontids” “perleidids,” groups widely distributed during Early-Middle Triassic.