En mosasaurie (Reptilia, Mosasauridae) av paleocensk ålder?
(2022) In Examensarbeten i geologi vid Lunds universitet GEOL01 20221Department of Geology
- Abstract
- Mosasaurs are a group of marine reptiles that are considered to have been the apex predators of the oceans during the Late Cretaceous. It is generally assumed that they, along with the last non-avian dinosaurs, died out during the mass extinction that marks the end of the Cretaceous. Recently, a mosasaur skull roof was discovered in a loose boulder on a beach in the vicinity of the town of Hanstholm in Denmark. The bedrock in the area comprises Paleocene limestone, but Cretaceous sediments also crop out nearby. The boulder was analyzed using, e.g., scanning electron microscopy (SEM) for calcareous nannofossils, particularly coccoliths. The results indicate a slightly younger age than the Cretaceous. Coccoliths were used as a... (More)
- Mosasaurs are a group of marine reptiles that are considered to have been the apex predators of the oceans during the Late Cretaceous. It is generally assumed that they, along with the last non-avian dinosaurs, died out during the mass extinction that marks the end of the Cretaceous. Recently, a mosasaur skull roof was discovered in a loose boulder on a beach in the vicinity of the town of Hanstholm in Denmark. The bedrock in the area comprises Paleocene limestone, but Cretaceous sediments also crop out nearby. The boulder was analyzed using, e.g., scanning electron microscopy (SEM) for calcareous nannofossils, particularly coccoliths. The results indicate a slightly younger age than the Cretaceous. Coccoliths were used as a chronostratigraphic proxy, and 57.5% of the specimens that were identified with some confidence to either genus or species level have their first appearance in the Danian (Paleocene). As neither contamination, reworking nor identification errors can be fully excluded, it is currently not possible to reach a firm conclusion about the age of the mosasaur fossil. However, my investigation justifies future, in-depth investigations into the stratigraphic age of the mosasaur-bearing block. (Less)
- Abstract (Swedish)
- Mosasaurierna utgör en grupp storvuxna ödlor som dominerade positionen som toppredatorer i haven under sen krittid. Det anses allmänt att dessa marina reptiler, tillsammans med de sista landlevande dinosaurierna, dog ut under det massutdöende som markerar övergången mellan krita och paleogen. Nyligen påträffades en del av ett skalltak tillhörande en mosasaurie i ett löst kalk- och flintblock på en strand utanför byn Hanstholm i Danmark. I området går paleocensk berggrund i dagen, men inte alltför långt borta förekommer även kretaceiska sediment. Genom analys av blockets nanofossilinnehåll (framför allt coccoliter) med hjälp av bl.a. svepelektronmikroskop (SEM) har resultat erhållits som tyder på en ålder som är något yngre än krita. 57,5%... (More)
- Mosasaurierna utgör en grupp storvuxna ödlor som dominerade positionen som toppredatorer i haven under sen krittid. Det anses allmänt att dessa marina reptiler, tillsammans med de sista landlevande dinosaurierna, dog ut under det massutdöende som markerar övergången mellan krita och paleogen. Nyligen påträffades en del av ett skalltak tillhörande en mosasaurie i ett löst kalk- och flintblock på en strand utanför byn Hanstholm i Danmark. I området går paleocensk berggrund i dagen, men inte alltför långt borta förekommer även kretaceiska sediment. Genom analys av blockets nanofossilinnehåll (framför allt coccoliter) med hjälp av bl.a. svepelektronmikroskop (SEM) har resultat erhållits som tyder på en ålder som är något yngre än krita. 57,5% av de nanofossil som med viss säkerhet kunde identifieras till släkt- och/eller artnivå förekommer endast under dan (paleocen) och framåt. Då varken kontaminering, omlagring eller identifieringsfel helt kan uteslutas går det dock inte att med säkerhet säga något om blockets ålder. Mina fynd borgar för framtida, mer ingående undersökningar av fossilets ålder. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9090331
- author
- Neumann, Daniel LU
- supervisor
-
- Isaline Demangel LU
- Johan Lindgren LU
- Sylvain Richoz LU
- organization
- course
- GEOL01 20221
- year
- 2022
- type
- M2 - Bachelor Degree
- subject
- keywords
- Coccolitoforer, dinoflagellater, krita, maastricht, mosasaurier, Mosasaurus, nanofossil, nanoliter, paleocen, paleogen
- publication/series
- Examensarbeten i geologi vid Lunds universitet
- report number
- 630
- language
- Swedish
- id
- 9090331
- date added to LUP
- 2022-06-20 11:17:00
- date last changed
- 2022-06-20 11:17:00
@misc{9090331,
abstract = {{Mosasaurs are a group of marine reptiles that are considered to have been the apex predators of the oceans during the Late Cretaceous. It is generally assumed that they, along with the last non-avian dinosaurs, died out during the mass extinction that marks the end of the Cretaceous. Recently, a mosasaur skull roof was discovered in a loose boulder on a beach in the vicinity of the town of Hanstholm in Denmark. The bedrock in the area comprises Paleocene limestone, but Cretaceous sediments also crop out nearby. The boulder was analyzed using, e.g., scanning electron microscopy (SEM) for calcareous nannofossils, particularly coccoliths. The results indicate a slightly younger age than the Cretaceous. Coccoliths were used as a chronostratigraphic proxy, and 57.5% of the specimens that were identified with some confidence to either genus or species level have their first appearance in the Danian (Paleocene). As neither contamination, reworking nor identification errors can be fully excluded, it is currently not possible to reach a firm conclusion about the age of the mosasaur fossil. However, my investigation justifies future, in-depth investigations into the stratigraphic age of the mosasaur-bearing block.}},
author = {{Neumann, Daniel}},
language = {{swe}},
note = {{Student Paper}},
series = {{Examensarbeten i geologi vid Lunds universitet}},
title = {{En mosasaurie (Reptilia, Mosasauridae) av paleocensk ålder?}},
year = {{2022}},
}