''Bonnerichthys'' is a genus of fossil fishes within the family Pachycormidae that lived during the Coniacian to

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

stage of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains of this

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

were first described from the Smoky Hill Member of the

Niobrara Chalk The Niobrara Formation , also called the Niobrara Chalk, is a Formation (stratigraphy), geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the La ...

Formation of Kansas (Late Coniacian-Early

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

), and additional material was later reported from the Pierre Shale, Mooreville Chalk, Demopolis Chalk, Wenonah Formation, and Moreno Formation, among other localities. It has also been reported in European Russia, specifically from the Rybushka Formation of the Saratov Region. It grew to at least in total body length, substantially less than the related ''

Leedsichthys ''Leedsichthys'' is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic.Liston, JJ (2004). An overview of the pachycormiform ''Leedsichthys''. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - Systema ...

'' from the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

which likely grew up to .

Feeding

One of the most significant features of ''Bonnerichthys'' is the recognition that it was a

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

, living on

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

. This recognition that many large-bodied fish from the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

in the Pachycormidae were filter feeders shows that this niche was filled for at least 100 million years before previously known. The modern niche is filled by several species of

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s and the

baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...

s. The international team that described the genus named it after the Marion Charles Bonner fossil hunting family, whose collections from the Niobrara Cretaceous chalk of western Kansas are in many museums and research institutions.

References

External links

''Bonnerichthys''
at the ''Oceans of Kansas'' website. Includes detailed taxonomic history, life restorations, bibliography, many photos of fossil remains.
''Bonnerichthys''
discussion at boneblogger.com Pachycormiformes Monotypic prehistoric ray-finned fish genera Late Cretaceous bony fish Late Cretaceous fish of North America Fossils of the United States Fossils of California Fossils of Mississippi Fossils of New Jersey Fossils of Texas Coniacian genus first appearances Santonian genera Campanian genera Maastrichtian genus extinctions Fossil taxa described in 2010 {{Cretaceous-fish-stub