Proteothrinax sp.
Classification: Elasmobranchii Hexanchiformes Chlamydoselachidae
Synonyms / new combinations and misspellings
Thrinax sp.
Thrinax sp.
Types
Proteothrinax sp.
Proteothrinax sp.
Description:
Citation: Proteothrinax sp. : In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 04/2024
Distribution Geographic
a: northwestern Hornby Island, British Columbia, Canada (Manning Point and Collishaw Point), described as Thrinax sp. [19279];
b: Hannan City and Kaizuka City, Osaka Prefecture, Southwest Japan, described as Thrinax sp. [2338];
c:
Distribution of Chlamydosechidae show google map
a: northwestern Hornby Island, British Columbia, Canada (Manning Point and Collishaw Point), described as Thrinax sp. [19279];
b: Hannan City and Kaizuka City, Osaka Prefecture, Southwest Japan, described as Thrinax sp. [2338];
c:
Distribution of Chlamydosechidae show google map
Distribution Strategraphy
a: green to blue-gray shale of the Lambert Formation, late Campanian to early Maastrichtian [19279];
b: Izumi Group, Upper Cretaceous, Maastrichtian [2338];
c:
a: green to blue-gray shale of the Lambert Formation, late Campanian to early Maastrichtian [19279];
b: Izumi Group, Upper Cretaceous, Maastrichtian [2338];
c:
Material
a:
b:
a:
b:
Discussion
maybe a junior synonym of Chlamydoselachus: RICHTER & WARD, 1990 p. 69 [2044] wrote: "Pfeil (1983, p. 112) based the genus Thrinax, type species: Thrinax baumgartneri, on two relatively complete teeth and two isolated crowns. They are separated from Chlamydoselachus by their upright unornamented crowns, labio-lingually short root and the absence of intermediate cusplets. In the same deposit Pfeil described Chlunzyabselachus fiedleri, based on 50 tooth fragments. Among his paratypes is a tooth, FHP 1982-D-107, intermediate in morphology between Chlamydoselachus and Thrinax. This tooth has a relatively small root, reduced ornamentation and no intermediate cusplets. Teeth of the Recent species Chlamydoselachus anguineus Garman 1884 may also lack intermediate cusplets and have considerable variation in the degree of coronal ornamentation (Pfeil 1983, pls 13-31; Welton 1979) We feel that the case for the existence of a separate chlamydoselachiid genus cannot be made on such limited material. It would appear that the criteria upon which Thrinax is separated from Chlamydoselachus are within the normal variation of Chlamydoselachus. We therefore regard Thrinax as a junior synonym of Chlamydoselachus and the type species, T. baumgartneri, is a junior synonym of Chlamydoselachus fiedleri."
CONSOLI, 2008 p. 287 [551]: "The Chatham chlamydoselachian is most comparable to Thrinax (synonymised with Chlamydoselachus by Richter and Ward (1990). The only species of this genus is T. baumgartneri Pfeil, 1983, which was made a junior synonym of C. fieldleri Pfeil, 1983."
maybe a junior synonym of Chlamydoselachus: RICHTER & WARD, 1990 p. 69 [2044] wrote: "Pfeil (1983, p. 112) based the genus Thrinax, type species: Thrinax baumgartneri, on two relatively complete teeth and two isolated crowns. They are separated from Chlamydoselachus by their upright unornamented crowns, labio-lingually short root and the absence of intermediate cusplets. In the same deposit Pfeil described Chlunzyabselachus fiedleri, based on 50 tooth fragments. Among his paratypes is a tooth, FHP 1982-D-107, intermediate in morphology between Chlamydoselachus and Thrinax. This tooth has a relatively small root, reduced ornamentation and no intermediate cusplets. Teeth of the Recent species Chlamydoselachus anguineus Garman 1884 may also lack intermediate cusplets and have considerable variation in the degree of coronal ornamentation (Pfeil 1983, pls 13-31; Welton 1979) We feel that the case for the existence of a separate chlamydoselachiid genus cannot be made on such limited material. It would appear that the criteria upon which Thrinax is separated from Chlamydoselachus are within the normal variation of Chlamydoselachus. We therefore regard Thrinax as a junior synonym of Chlamydoselachus and the type species, T. baumgartneri, is a junior synonym of Chlamydoselachus fiedleri."
CONSOLI, 2008 p. 287 [551]: "The Chatham chlamydoselachian is most comparable to Thrinax (synonymised with Chlamydoselachus by Richter and Ward (1990). The only species of this genus is T. baumgartneri Pfeil, 1983, which was made a junior synonym of C. fieldleri Pfeil, 1983."
Remarks
shark-references Species-ID=12647;
shark-references Species-ID=12647;
References
