Giant Swimming Mouth: The Ancient Mega-Fish.

Researchers have found that the size of ancient armored fish from the late Devonian period cannot be judged based on the size of modern-day sharks. A new analysis of data from previous studies suggests that previous estimates of the size of the Dunkleosteus species were probably wide of the mark. The new research suggests that the Dunkleosteus species actually had shorter bodies compared to their gaping mouths, with proportions between head size and body size that don't match what we see with the sharks of today. The largest Dunkleosteus only grew to about 4 meters, or 13 feet, in length.