Spinocaudichthys, Cromeria, Gigantura and Stylephorus

Spinocaudichthys oumtkoutensi (Filleul A and Dutheil DB 2001, Poi-SGM 20a, 3.5cm long, Cenomanian, Early Cretaceous) was originally considered a tiny acanthomorph, but in the LRT nests with extant sticklebacks, like Gasterosteus.

Cromeria nilotica (Boulenger 1901; 4.5cm) is an extant tiny African naked shellear.. Two species are shown above.

Stylephorus chordatus feeding and ontogeny

Stylephorus chordatus (Shaw, 1791, Regan 1924, aka Stylophorus) is the extant tube-eye or thread-tail. It was considered a deep-sea oarfish relative, but here nests with an African river fish, Cromeria. Note the large eyes and flexible neck. Convergent with seahorses and oarfish, the tube-eye feeds on tiny plankton sucked in as its tubular mouth enlarges the oral cavity by 40x.

Gigantura indica (Brauer A 1901, Konstantinidis and Johnson 2016; 20 cm standard length, not counting caudal fin) is the extant telescope fish. Here it nests with Stylophorus. The postorbital (= circumorbital ring) is reduced to vestiges. Note the horizontal teeth protruding from the anterior dentary along with regular vertical teeth. Related taxa do not have such large teeth. This small fish can swallow prey larger than itself.

Boulenger GA 1901. Diagnoses of new fishes discovered by Mr. W. L. S. Loat in the Nile. Annals and Magazine of Natural History, Including Zoology, Botany and Geology, Being a Continuation of the 'Magazine of Botany and Zoology', and of Louden and Charlesworth's 'Magazine of Natural History', Series 7 8: 444-446.

Brauer A 1901. Über einige von der Valdivia-Expedition gesammelte Tiefseefische und ihre Augen. Sitzungsberichte der Gesellschaft zur Beförderung der Gesamten Naturwissenschaften zu Marburg 8: 115–130.

Filleul A and Dutheil DB 2001. Spinocaudichthys oumtkoutensis a freshwater acanthomorph from the Cenomanian Morocco. Journal of Vertebrate Paleontology 21(4):774–780.

Konstantinidis P and Johnson GD 2016. Osteology of the telescope fishes of the genus Gigantura (Brauer, 1901), Teleostei: Aulopiformes. Zoological Journal of the Linnean Society 179(2):338–353.

Regan CT 1924. The morphology of the rare oceanic fish, Stylophorus chordatus, Shaw; based on specimens collected in the Atlantic by the "Dana" expeditions, 1920–1922. Proceedings of the Royal Society B 96(674): PDF

Shaw G 1791. Description of the Stylephorus chordatus, a new fish. Transactions of the Linnean Society of London, 2d Ser: Zoology 1:90–92.

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