Ancient giant armoured fish fed in a similar way to basking sharks

Scientists from the University of Bristol and the University of Zurich have shown that the Titanichthys - a giant armoured fish that lived in the seas and oceans of the late Devonian period 380-million-years ago - fed in a similar manner to modern day basking sharks. Titanichthys has long been known as one of the largest animals of the Devonian - its exact size is difficult to determine, but it likely exceeded five metres in length; like in the basking shark, its lower jaw reached lengths exceeding one metre. However, unlike its similarly giant contemporary Dunkleosteus , there is no previous evidence of how Titanichthys fed. Where the lower jaw of Dunkleosteus and many of its relatives had clear fangs and crushing plates, the lower jaw of Titanichthys is narrow and lacking any dentition or sharp edges suitable for cutting. Consequently, Titanichthys has been presumed to have been a suspension-feeder, feeding on minute plankton by swimming slowly with the mouth opened widely through water to capture high concentrations of plankton - a technique called continuous ram feeding. However, this has remained uncertain, as no fossilised evidence of suspension-feeding structures such as elongate projections that cover the gills in modern suspension-feeding fish has ever been found. Instead, the team sought to investigate the question indirectly, using biomechanical analysis to compare the lower jaw of Titanichthys with those of other species.