Titanichthys

Titanichthys
Temporal range: Famennian
T. agassizi
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Class: †Placodermi
Order: †Arthrodira
Suborder: †Brachythoraci
Infraorder: †Coccosteina
Superfamily: †Dinichthyloidea
Family: †Titanichthyidae
Genus: †Titanichthys
Species: †T. agassizi
Type species
Titanichthys agassizi
Newberry, 1885
Synonyms

Brontichthys

Titanichthys is a genus of giant, aberrant marine placoderm from shallow seas the Late Devonian of Morocco, Eastern North America, and possibly Europe.[1] Many of the species approached Dunkleosteus in size and build. Unlike its relative, however, the various species of Titanichys had small, ineffective-looking mouth-plates that lacked a sharp cutting edge. It is assumed that Titanichthys was a filter feeder that used its capacious mouth to swallow or inhale schools of small, anchovy-like fish, or possibly krill-like zooplankton, and that the mouth-plates retained the prey while allowing the water to escape as it closed its mouth.

Species

The genus shows a great diversity in the Famennian-aged Cleveland Shales, though species are also found in similarly aged strata in Morocco and possibly the Holy Cross Mountains in Poland.[1]

T. agassizi

This is the type species, from the Cleveland Shales. Its infrognathals are strongly recurved medially, and is elongated with a spatula-like process at the anterior end. The headshield averages about 60 cm in length.[1]

T. attenuatus

This Cleveland Shales species is based on an infragnathal bone more than 36 cm in length. May possibly be a synonym of T. agassizi.[2]

T. clarkii

This Cleveland Shales species has infragnathals that are not as recurved as T. agassizi's. The cranial roof is comparatively narrower and more rounded. It is the largest known species in the genus, and possibly one of the largest Devonian vertebrates known. The head is about 90 cm in length.[2]

T. hussakofi

This Cleveland Shales species is known from a badly preserved, incomplete infragnathal. It was originally described by Claypole as "Brontichthys clarki" in 1894.[2] As "Brontichthys" is a junior synonym of Titanichthys, it should not be confused with another, similarly-named arthrodire, Bruntonichthys of Dunkleosteidae.

T. rectus

This Cleveland Shales species has an infragnathal as large as that of T. clarkii, though T. rectus' infragnathal is much straighter, and does not have a spatula-like process on its anterior end.[2]

T. kozlowskii

This species placement within the genus is in doubt. It is based on incomplete nuchal and central plates found in Upper Famennian-aged marine strata of the Holy Cross Mountains in Poland.[2]

Titanichthys termieri from Late Devonian of Morocco

T. termieri

This species is found in Lower Famennian-aged marine strata of Tafilalet, Southern Morocco. The fossil material of this species strongly suggests it is as large as the Cleveland Shales' T. clarkii.[2] The average combined length of the head and trunk shields for T. termieri is estimated to be 200 cm.[2] When the first fossils of T. termieri were found by geologist Henri Termier, the specimens were originally placed within the genus Gorgonichthys - that is, after Termier was able to convince his colleagues that the bone scraps were of a placoderm, and not a dinosaur.[3]

Footnotes

  1. 1 2 3 Denison, Robert (1978). Placodermi Volume 2 of Handbook of Paleoichthyology'. Stuttgart New York: Gustav Fischer Verlag. p. 100. ISBN 978-0-89574-027-4.
  2. 1 2 3 4 5 6 7 Denison, Robert (1978). Placodermi Volume 2 of Handbook of Paleoichthyology'. Stuttgart New York: Gustav Fischer Verlag. p. 101. ISBN 978-0-89574-027-4.
  3. ↑ See Janvier (1998) p.323 for details.

References


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