''Rolfodon'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

in the family Chlamydoselachidae. It is closely related to the extant frilled sharks in the genus '' Chlamydoselachus'', which it can be differentiated from by tooth morphology. It is named after late Canadian paleontologist Rolf Ludvigsen. The earliest fossil teeth of ''Rolfodon'' are known from 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 ...

(

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

boundary) of Japan, and it is one of two genera of Chlamydoselachidae along with ''Chlamydoselachus'' known to have survived the

Cretaceous–Paleogene extinction event The Cretaceous–Paleogene (K–Pg) extinction event, also known as the K–T extinction, was the extinction event, mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event cau ...

, although unlike ''Chlamydoselachus'', ''Rolfodon'' went extinct by the

Early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

. Remains are known from worldwide, including Japan, Canada,

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

, and

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. As with modern frilled sharks, ''Rolfodon'' appears to have been specialized to deep-water environments.

Species

The following species are known: * ''R. bracheri'' (Pfeil, 1983) – Early Miocene ( Aquitanian to

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

) of Austria, Germany & Japan * ''R. fiedleri'' (Pfeil, 1983) – Late Eocene (

Bartonian The Bartonian is, in the International Commission on Stratigraphy's (ICS) geologic time scale, a stage or age in the middle of the Eocene Epoch or Series. The Bartonian Age spans the time between . It is preceded by the Lutetian and is follow ...

) of Austria * ''R. goliath'' ( Antunes & Cappetta, 2002) – Late Cretaceous (

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 ...

) of Angola * ''R. keyesi'' (Mannering & Hiller 2008) – Early Paleocene of New Zealand * ''R. landinii'' (Carrillo-Briceño et al. 2014) – Middle Miocene (

Langhian The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene Epoch/Series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma (million years ago) during the Middle Miocene.GeoWhen (2007) The Langhian was ...

Serravallian The Serravallian is, in the geologic timescale, an List of time periods, age or a stage (stratigraphy), stage in the middle Miocene epoch (geology), Epoch/series (stratigraphy), Series, which spans the time between 13.82 annum, Ma and 11.63 Ma (m ...

) of Ecuador * ''R. ludvigseni'' Cappetta, Morrison & Adnet, 2019 – Campanian of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, Canada ( Northumberland Formation) * ''R. tatere'' (Consoli, 2008) – Late Cretaceous (

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 ...

) to Early Paleocene of New Zealand and Antarctica * ''R. thomsoni'' (Richter & Ward, 1990) – Maastrichtian of Antarctica The majority of these species were previously classified in ''Chlamydoselachus''. One species, ''Chlamydoselachus baumgartneri'', was moved to its own genus ''Proteothrinax'' in 2012. ''P. baumgartneri'' was later found to be conspecific with the previously described ''C. fiedleri'', but ''fiedleri'' was found to belong to ''Rolfodon'' by Cappeta ''et al'' (2019). In addition to the genus as a whole, one individual species is also known to have survived the Cretaceous-Paleogene extinction event: ''R. tatere'', which was first described from the Early Paleocene of New Zealand and was later also identified from the Late Cretaceous of Antarctica, extending the record of its existence by over 10 million years. ''R. bracheri'' from the Early Miocene was one of the most widespread species, with fossil teeth known from the European

Paratethys The Paratethys sea, Paratethys ocean, Paratethys realm or just Paratethys (meaning "beside Tethys"), was a large shallow inland sea that covered much of mainland Europe and parts of western Asia during the middle to late Cenozoic, from the lat ...

and from Japan. The last records of ''Rolfodon'' are indeterminate teeth from the

of Japan. ''R. goliath'', from the Late Campanian of Angola's southern Benguela Basin, could grow to very large sizes. It was described by Miguel Telles Antunes and Henri Cappetta in 2002 during the beginning stages of the PaleoAngola project. The holotype, MUS ANG 23, is rather large. This tooth is about 20mm high, and is characterised by straightened, upright cusps with smooth enameloid which lack ornamentation.Carlsen, A.W. & Cuny, G. 2014. A study of the sharks and rays from the Lillebælt Clay (Early–Middle Eocene) of Denmark, and their palaeoecology. © 2014 by Bulletin of the Geological Society of Denmark, Vol. 62, pp. 39–88. ISSN 2245-7070.
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References

{{Taxonbar, from=Q115009812 Chlamydoselachidae Prehistoric shark genera Campanian genus first appearances Prehistoric fish of Oceania Fossil taxa described in 2019 Messinian genus extinctions