PRIMITIVE JAW STRUCTURE IN AN ARTICULATED BRACHYTHORACID ARTHRODIRE (PLACODERM FISH; EARLY DEVONIAN) FROM SOUTHEASTERN AUSTRALIA

Publication Type:Journal Article
Year of Publication:2001
Authors:YOUNG, GC, Lelièvre, H, GOUJET, D
Journal:Journal of Vertebrate Paleontology
Volume:21
Issue:4
Date Published:2001
ISBN Number:0272-4634
Keywords:Corvidae, Corvus, Corvus corone
Abstract:Abstract A unique ?buchanosteid? arthrodire specimen from Emsian limestones at Burrinjuck represents the complete articulated remains of the head and cheek, and most of the trunk armor bones from a single fish, together with well-ossified braincase and jaw cartilages. The structure of the toothplates and jaws are described, and compared with primitive brachythoracid material from Saudi Arabia of similar age. Both the palatoquadrate and meckelian cartilages are well preserved, and perichondrally ossified as single elements. As previously described in some phlyctaeniids, the dermal gnathal elements carry crowded denticles similar to the normal tubercular ornament, enlarged along anterior and lateral margins. Six characters concerning gnathal plates of brachythoracids, which have been used in phylogenetic analysis, are discussed and reformulated.Abstract A unique ?buchanosteid? arthrodire specimen from Emsian limestones at Burrinjuck represents the complete articulated remains of the head and cheek, and most of the trunk armor bones from a single fish, together with well-ossified braincase and jaw cartilages. The structure of the toothplates and jaws are described, and compared with primitive brachythoracid material from Saudi Arabia of similar age. Both the palatoquadrate and meckelian cartilages are well preserved, and perichondrally ossified as single elements. As previously described in some phlyctaeniids, the dermal gnathal elements carry crowded denticles similar to the normal tubercular ornament, enlarged along anterior and lateral margins. Six characters concerning gnathal plates of brachythoracids, which have been used in phylogenetic analysis, are discussed and reformulated.
URL:http://dx.doi.org/10.1671/0272-4634(2001)021[0670:PJSIAA]2.0.CO;2
Short Title:Journal of Vertebrate Paleontology
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith