Pterichthyodes

Taxobox
name = "Pterichthyodes"
status = fossil
fossil_range = Devonian


regnum = Animalia
phylum = Chordata
classis = Placodermi
genus = "Pterichthyodes"

"Pterichthyodes" is a genus of placoderm fishes from the Devonian period, now all extinct. They were one of the first species recognized for what they were, as their fossils are common in the Old Red Sandstone formation studied by geologists in the early 1800s. Due to their extreme divergence from modern-day fish, they were a puzzle unsolved until Charles Darwin brought forward his theories on evolution. "PterichthySpecimen of the Pterichthys Milleri or Sea Scorpion Showing Body Armour.gifodes" had heavily armored heads and front bodies, while their tail ends were uncovered. As placoderms, they were members of one of the first group of animals to possess jaws, though they had grinding plates rather than teeth. The "Pterichthyodes" are distinguished easily from other placoderms by their odd wing-like appendage where fins would be found on a modern fish ("pterichthys" is Ancient Greek for "wing-fish") -- strictly speaking, these are not fins as we normally think of them, which evolved in another group of fish, the Actinopterygii.

External links

* [http://www.palaeos.com/Vertebrates/Units/Unit060/060.200.html#Asterolepidoidei A page devoted to Asterolepidoidei, the parent group of the pterichthyodes according to cladistics]