Xiphactinus audax, the X fish skull Pteranodon Pikaia is a representative member

Pikaia is a representative member of the chordate group from which we undoubtedly arose

probably skimming the water to find prey

ischigualastensis (the species name is from the Ischigualasto Formation of northwestern Argentina

so there is a huge incentive to “enhance” a tooth

americanum was around 2

Xiphactinus audax, the X fish skull Pteranodon Pikaia is a representative memberXiphactinus audax (from Latin and Greek for "audacious sword ray") was a large, 15 to 20 foot long predatory bony fish that lived in the Niobraran Sea, in what is now North America, during the Late Cretaceous. When alive, the beast would have resembled a gargantuan, fanged tarpon. Skeletal remains of Xiphactinus have come from Kansas, Alabama, and Georgia. Despite being preyed on by sharks and mosasaurs, X. audax was, nonetheless, a voracious predator