Dinichthyidae

From Palaeos

Placodermi
`--Arthrodira
   `--Eubrachythoraci
      `--Pachyosteomorphi
         |--Erromenosteus
         |--Dinichthyidae
         |--Trematosteidae
         `--Aspinothoraci
            |--Rachiosteus 
            |--Pachyosteus
            |--Titanichthys
            |--Bungartius
            |--Selenosteidae
            `--Mylostomatidae

[edit] Introduction

Beginning from relatively small forms, some advanced and predatory Arthrodires, representing the family Dinichthyidae, increased greatly in size, perhaps exploiting the food source provided by diversifying sharks and bony fish. The largest genus of this group, Dunkleosteus, was a true superpredator of the latest Devonian (Fammenian epoch), reaching 5 to as much as 9 meters in length. The mighty head-shield alone (see above photo) was upto a meter in height in large forms. Note the sharpened edges of the jaw, which functioned as shearing teeth. Like other sharp-sighted vertebrates, particularly aquatic vertebrate predators, (birds, ichthyosaurs, some thecodonts and dinosaurs) the eye sockets are protected by a bony ring to prevent injury, and in the case of those who were/are aquatic, to prevent water pressure from crushing them. Unlike other vertebrates, and like other placoderms, the bony eye-rings of Dinichthyids were derived from an already ossified eyeball.

[edit] Taxonomy

Family: Dinichthyidae

Author: Newberry, 1885

Synonym: Dunkleosteidae

[edit] List of genera

• Bruntonichthys U. Dev. Aus.
• Bullerichthys U. Dev. Aus.
• Dinichthys [Ponerichthys] U. Dev. NA. [=Dunkleosteus??]
• Dunkleosteus U. Dev. Eu. EEu. NAf. NA.
• Eastmanosteus Obruchev, 1964; M. Dev. NAf. M.-U. Dev. NA. U. Dev. Eu. EEu. SWAs. Aus.
• Gorgonichthys U. Dev. NA.
• Hadrosteus U. Dev. Eu.
• Heintzichthys [Stenognathus] U. Dev. NA.? EEu.
• Holdenius U. Dev. NA.
• Hussakofia [Brachygnathus] U. Dev. NA.
• Kianyousteus M. Dev. EAs.
• Squamatognathus

[edit] References

[edit] Credits

MAK061011