A study by Sallan and Coates was published online July 22 in the Zoological Journal of the Linnean Society.
"These early, post-Devonian ray-finned fish provide the first glimpse of what is to come: an evolutionary profusion of body forms, fin shapes, and extraordinary jaws and teeth. The ray-finned fish really do exemplify Darwin's comment about 'endless forms most beautiful and wonderful,'" Coates said.
There are around 30,000 species of ray-finned fish today, comprising nearly 99 percent of all fish species. Think of the word "fish" and the image that pops into your mind will likely be a ray-finned fish, members of a ubiquitous class that includes everything from tuna to trout, catfish to cod, swordfish to sunfish, perch to piranha, goldfish to goby.
After re-evaluating fossils from sites in Scotland dating to 348 million years ago, Sallan and Coates concluded that Fouldenia and its relative Styracopterus, which previous researchers had classified as the same species, are in fact separate genera. A genus is the category of biological classification between the family and the species.
Sallan and Coates determined that Fouldenia had massive tooth plates on its upper and lower jaws, suitable for preying on hard-shelled animals. It resembled modern-day jacks, which include the Japanese amberjack, or yellowtail, familiar to sushi lovers. Styracopterus was an early mimic of modern deep-bodied fish such as the angelfish. Both of these primeval fish were less than 10 inches long.
"Those Scottish fossil beds have four or five known genera of ray-finned fish in them. They all look completely different, and they all do completely different things," Sallan said.
The same sites have also produced some of the earliest post-Devonian tetrapods, four-limbed creatures that included
|Contact: Jim Erickson|
University of Michigan