Rhipidistia

From Freepedia

? Rhipidistia
Image:Coelacanth.png Coelacanth
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sarcopterygii Infraclass: Crossopterygii See also text Infraclass: Rhipidistia
Orders
See text

The Rhipidistia are an extinct type of lobe-finned fishes. Traditionally the Rhipidisitia were a subgroup of Crossopterygii described a group of fish that lived during the Devonian consisting of the Porolepiformes and Osteolepiformes. However as cladistic understanding of the vertebrates has evolved over the last few decades a monophyletic Rhipidistia should now be understood to be an ancestor for the whole of Tetrapoda. Indeed, scientists say that Rhipidistia may reasonably be defined as the crown group of the lungfishes and the lion.

Cladistic taxonomy:

Rhipidistia

• Dipnomorpha
  • Porolepiformes
    • Powichthys
  • Dipnoi
• Tetrapodomorpha
  • Rhizodontiformes
  • Osteolepidida
    • Osteolepiformes
      • Tristichopteridae
      • Elpistostegalia
        • Panderichthys
        • Tetrapoda

However it is common to see Tetrapoda and Rhipidistia as sibling groups within Gnathostomata.

References

• palaeos.com page
• Taxonomicon page