Tselfatiiformes is an extinct order of from the infraclass Teleostei.[Joseph S. Nelson: Fishes of the World. John Wiley & Sons, 2006, .]
The order appeared in the upper Albian on the coasts of Europe and North Africa and spread during the Cenomanian and Turonian on the Proto Atlantic to the coasts of northern South America, the Gulf of Mexico and into the Western Interior Seaway.
Features
The genera and species of the Tselfatiiformes had a high-backed body. The dorsal fin took up most of the length of the back. The pectoral fins were high. Ventral fins could be present or absent; if present, they were supported by six or seven fin rays. The caudal fin was forked and had 18 main fin rays. The majority of the fin rays were unsegmented. The upper jaw was formed by the
premaxilla and
maxilla. The palate was also toothed.
Systematics
The tselfatiiforms could not initially be assigned to a larger kinship group within the Teleostei.
[Louis Taverne & Mireille Gayet: Phylogenetical relationships and palaeozoogeography of the marine Cretaceous Tselfatiiformes (Teleostei, Clupeocephala). Cybium 2005, 29 (1)] More recent cladistic studies on the basis of their osteological characteristics have made it clear that they are primitive
and represent the plesiomorphic sister group of a clade from
Otocephala (
Clupeomorpha and
Ostariophysi)
[Arratia, G., 2010: The Clupeocephala revisited: Analysis of characters and homologies. Revista de Biologia Marina & Oceanografia 45: 635–657. Reference page.
] and
Euteleostei.
