University of Oklahoma paleontologists Joseph Frederickson, Thomas Lipka, and Richard Cifelli have named and described a new species of lungfish that once cruised the swampy waterways of Cretaceous Maryland. Called Ceratodus kranzi, the animal is known from a tooth-studded portion of an upper jaw, which was discovered at the Dinosaur Park quarry by Thomas Lipka. The species name, kranzi, honors Maryland paleontologist and Dinosaur Park interpreter Peter Kranz.
Lungfish first evolved around 380 million years ago, during the Devonian Period. As the name suggests, these fish have simple lungs – actually a jury-rigged swim bladder – that let them breathe while out of the water. While they cannot move very fast or far on land, lungfish can wait around for extended periods if a pond dries up around them. Lungfish were among the first backboned animals to evolve the ability to survive on land. Although they are not our direct ancestors, lungfish are more closely related to tetrapods (four-legged animals, including amphibians, reptiles, and mammals) than they are to most other fish. There are six species of lungfish living today, but they are limited to the Southern hemisphere.
Lungfish fossils from the Age of Dinosaurs have been found on every continent except Antarctica. Nevertheless, they are rare finds, and the diversity and distribution of these animals through deep time is poorly understood. This is particularly true in the eastern United States. Before the discovery of Ceratodus kranzi, only one other Cretaceous lungfish was known from the east coast.
Ceratodus kranzi is also notable for its size. Frederickson and colleagues estimate that it grew to six feet in length, comparable to the giant Queensland lungfish of Australia. This would have been big enough to be a formidable predator in Maryland’s prehistoric swamps and ponds. It probably fed on frogs, salamanders, and smaller fish – but it could have also snapped up a baby dinosaur if given an opportunity!
Frederickson, J.A., Lipka, T.R., and Cifelli, R.L. (2016). A new species of the lungfish Ceratodus (Dipnoi) from the Early Cretaceous of the eastern U.S.A. Journal of Vertebrate Paleontology.