The circum-Pacific Jurassic fish record is very poor in comparison with the contemporaneous European assemblages (e.g., France, England, Germany). Fishes have been reported from continental and marine sediments. Most recent descriptions are from North America (Schaeffer and Patterson 1984) and Chile (Arratia 1987). The majority of the recognized taxa from other areas need modern systematic revision (Schaeffer and Patterson 1984; Arratia 1987; Cione and Pereira 1987, 1990; Cione et al. 1987).

The record includes typical assemblages whose low diversities are mostly due to poor sampling. Marine facies in Argentina, Chile, Mexico, the United States, Canada, and Japan include a few hybodontoids and holocephalans, halecostomes incertae sedis, semionotids, a few pycnodontiforms, caturids, amiids, pholidophorids, pachycormids, aspidorhynchids, ichthyodectiformosteoglossomorphs incertae sedis, and several genera identified as Teleostei incertae sedis. Freshwater facies in Argentina, the United States, China, Australia, and Antarctica include coccolepids, redfieldiids, semionotids, ichthyodectiformosteoglossomorphs incertae sedis, coelacanths, and dipnoans. Chondrichthyans and pycnodontiforms, which are fairly common in Europe, are very rare, and macrosemmids, ionoscopids, and oligopleurids have not been reported. Chondrosteans and coelacanths are restricted to continental facies.

The record of some supposedly well known genera such as Hybodus, Pholidophorus, or Leptolepisin different areas may be highly misleading, as Schaeffer and Patterson (1984) indicated. These temporally and geographically wide ranging taxa are nonmonophyletic according to cladistic methodology. This fact, together with the provisional systematics of the remaining fishes, makes paleobiogeography or correlation highly speculative.