Osteoglossidae

Osteoglossidae is a family of large-sized freshwater fish, which includes the arowanas. They are commonly known as bonytongues. The family has been regarded as containing two extant subfamilies Arapaiminae and Osteoglossinae, with a total of five living genera,<ref>Template:Cite encyclopedia</ref> but these are regarded as valid families in Eschmeyer's Catalog of Fishes<ref name =ECoF>Template:Cite web</ref> The extinct Phareodontinae are known from worldwide during the Late Cretaceous and Paleogene; they are generally considered to be crown group osteoglossids that are more closely related to one of the extant osteoglossid subfamilies than the other, though their exact position varies.<ref name=":0">Template:Cite journal</ref><ref name=":3">Template:Cite journal</ref>

Evolution

Osteoglossids are basal teleosts that originated during the Cretaceous, and are placed in the actinopterygian order Osteoglossiformes. The traditionally defined wider family includes several extant species from South America, one from Africa, two from Asia, and two from Australia.<ref>Template:Cite book</ref> The earliest known osteoglossid is Cretophareodus from the middle Campanian of the Dinosaur Park Formation, Canada, but a potentially older genus may be Chanopsis from the Albian of the Democratic Republic of the Congo.<ref>Template:Cite journal</ref>

Although currently restricted to freshwater habitats in the tropics, the group was much more widespread during the Cretaceous and Paleogene, with genera known from North America and Europe, including marine taxa such as Brychaetus. An indeterminate marine osteoglossid is known to have inhabited the seas around Greenland in the Early Paleocene, and they later become diverse in marine habitats during the Eocene, with many genera known from Europe.<ref>Template:Cite journal</ref><ref name=":2" />

Modern osteoglossids of both subfamilies have a roughly Gondwanan distribution confined to freshwater habitats. For this reason, it was formerly assumed that extant osteoglossids descend from an ancestor that inhabited the supercontinent of Gondwana during the Mesozoic, which split into different genera following its fragmentation. However, more recent studies have found that many of the closest extinct relatives to extant osteoglossid genera were marine fish, and thus that their current distribution likely originates from marine dispersal between different continents during the Paleogene. Incorporating both extant and extinct osteoglossids, at least four different colonizations of freshwater habitats from marine ones are predicted to have occurred.<ref name=":3" />

Taxonomy

The following taxa are known from the family:<ref name=":0" /><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name=":1">Template:Cite thesis</ref>

• File:Phareodus testis, Buffalo Museum of Science cropped.jpg

  Phareodus testis, a famous member of the extinct subfamily Phareodontinae

  Family Osteoglossidae Bonaparte, 1831
  • Genus ?†Chanopsis Casier, 1961
  • Genus ?†Chauliopareion Murray and Wilson, 2005 (possibly a basal osteoglossiform)<ref name=":0" />
  • Genus †Heterosteoglossum Bonde, 2008 (possibly an arapaimine)<ref name=":3" /><ref name=":2" />
  • Genus ?†Singida Greenwood & Patterson, 1967 (possibly a basal osteoglossiform)<ref name=":0" />
  • Genus †Xosteoglossid Bonde, 2008 (possibly an arapaimine)<ref name=":3" /><ref name=":2" />
  • Subfamily Osteoglossinae Bonaparte, 1831
    • Genus Osteoglossum Cuvier, 1829
    • Genus Scleropages Günther, 1864
  • Subfamily †Phareodontinae D. S. Jordan, 1925<ref name=":3" />
    • Genus †Brychaetoides Bonde, 2008<ref name=":2">Template:Cite journal</ref>
    • Genus †Brychaetus Woodward, 1901
    • Genus †Cretophareodus Li, 1996
    • Genus ?†Foreyichthys Taverne, 1979
    • Genus †Furichthys Bonde, 2008<ref name=":2" />
    • Genus †Macroprosopon Capobianco, Zouhri & Friedman, 2024<ref>Template:Cite journal</ref>
    • Genus †Magnigena Forey & Hilton, 2010
    • Genus †Monopteros Volta, 1796
    • Genus †Musperia Sanders, 1934
    • Genus ?†Opsithrissops Daniltshenko, 1968
    • Genus †Phareoides Taverne, 1973 (sometimes treated as synonymous with Phareodus)
    • Genus †Phareodus Leidy, 1873
    • Genus †Phareodusichthys Gayet, 1991
    • Genus †Ridewoodichthys Taverne, 2009
    • Genus †Taverneichthys Kumar, Rana & Paliwal, 2005<ref>Template:Cite journal</ref>

The Phareodontinae is sometimes treated as a valid family, the Phareodontidae, proposed by Jordan in 1925.<ref name = VdL>Template:Cite journal</ref>