New collaborative research conducted on the fish block currently on display in the Grounds for Discovery exhibit, contributes to the reinterpretation of the family relationship of osteoglossomorph fishes. Dr. Allison Murray, University of Alberta, Dr. Darla Zelenitsky, University of Calgary, and Dr. Donald Brinkman and Andrew Neuman, Executive Director, from the Royal Tyrrell Museum of Palaeontology have analyzed the specimens and compared them to other articulated and isolated specimens.
Osteoglossomorphs or “bony tongues” as they are commonly known, are bony fishes that can be found living in South America, Africa, and South-East Asia. They are related to the goldeye and mooneye, which are still commonly found in rivers and lakes in western North America. Osteoglossomorphs are one of the most primitive groups of living bony fishes. They are unique among living fishes in that they use their tongues when biting along with their strongly-toothed jaws, which contain big, conical, sharp teeth.
Articulated (when elements of the skeleton are connected) fish specimens are rare. Fishes are more commonly represented in the fossil record by disarticulated (when the skeleton is disconnected) or isolated bones. These microfossils are often difficult to identify as belonging to specific groups.
This block of sandstone with five articulated fishes was discovered in 2015 by Edgar Nernberg, a heavy equipment operator for Keystone Excavating, while excavating for new residence development in Calgary. These specimens are thought to have been preserved when a group of fish was trapped in a pond after a flood. Two of the fishes are a new species of the genus Joffrichthys, Joffrichthys tanyourus, and three are a new genus and species, Lopadichthys colwellae.
Due to the excellent preservation of complete fish skeletons in this sandstone block, researchers were able to identify some isolated jaws and vertebrae as being similar to one of the fish in the block. These isolated bones have been found in widely separated localities, showing that this fish was widely distributed in the western part of North America.
Since complete fossil fish are rare from this time period (early Palaeogene) in Alberta, these new specimens allowed researchers to learn more about what kind of fish survived the end-Cretaceous extinction 66 million years ago, and to fill gaps in the osteoglossomorph family tree. Study of this new species of Joffrichthys reveals that the genus is not as closely related to modern South American forms as previously thought.