Conodonts of Khoshyeilagh Formation, the most complete section of Devonian rocks in the Alborz Mountains, northern Iran, has been studied, and subspecies of the genera Icriodus, Bipennatus, Polygnathus, Pelekysgnathus, Ancyrodella, Palmatolepis, Bispathodus, Scaphignathus, Clydagnathus, Gnathodus, Scaliognathus and Dollymae have been obtained from the studied section. The faunas indicate an Eif...

Progressive biomineralization of a skeleton occurs during ontogeny in most animals. In fishes, larvae are poorly mineralized, whereas juveniles and adults display a progressively more biomineralized skeleton. Fossil remains primarily consist of adult specimens because the fossilization of poorly-mineralized larvae and juveniles necessitates exceptional conditions. The Miguasha Fossil-Lagerstätt...

All species of Barycrinus from the early Osagean Burlington Limestone of the United States midcontinent are reviewed. Burlington Barycrinus species include: B. rhombiferus (Owen and Shumard, 1852); B. magister (Hall, 1858); B. spurius (Hall, 1858); B. crassibrachiatus (Hall, 1860); B. scitulus (Meek and Worthen, 1860) n. combination; and B. sampsoni Miller and Gurley, 1896. Cyathocrinus latus H...

As the sister lineage of all other actinopterygians, the Middle to Late Devonian (Eifelian-Frasnian) Cheirolepis occupies a pivotal position in vertebrate phylogeny. Although the dermal skeleton of this taxon has been exhaustively described, very little of its endoskeleton is known, leaving questions of neurocranial and fin evolution in early ray-finned fishes unresolved. The model for early ac...