La Meseta Formation

The La Meseta Formation is a sedimentary sequence deposited during the Eocene on Seymour Island off the coast of the Antarctic Peninsula. It is noted for its fossils, which include both marine organisms and the only terrestrial vertebrate fossils from the Cenozoic of Antarctica.[2][4]

This article is about an Antarctica sedimentary sequence. For the geological feature, see Mesa. For other uses, see Meseta.
La Meseta Formation
Stratigraphic range:
TypeGeological formation
Unit ofSeymour Island Group[1]
UnderliesWeddell Formation
OverliesLopez de Bertodano, Sobral & Cross Valley Formations
Thickness557 m (1,827 ft)[2]
Lithology
PrimarySandstone, claystone
OtherSiltstone, mudstone, conglomerate
Location
Coordinates64°14′21.782″S 56°36′11.69″W.[3]
Approximate paleocoordinates63.7°S 61.5°W / -63.7; -61.5
RegionSeymour Island
CountryAntarctica

Geologic map of Seymour Island, Antarctica with La Meseta Formation in dark yellow

Description

La Meseta Formation lies unconformably on the Cretaceous Lopez de Bertodano Formation. It is an approximately 557 metres (1,827 ft) thick sequence of poorly consolidated sandstones and siltstones. The depositional environment was probably coastal, deltaic or estuarine in character. The top of the sequence is an erosional unconformity to Pleistocene glacial gravels.[3][2] La Meseta Formation is one of the sequences that make up the fill of the Late Jurassic to Paleogene James Ross Basin.[3]

Paleoenvironment

The terrestrial environment surrounding the deposition area is thought to have been a temperate polar forest, including podocarp and araucarian conifers, as well as Nothofagus.[5][6]

Paleobiota

La Meseta Formation is extremely rich in fossils. Among mammals, the meridiungulata Antarctodon and Trigonostylops have been found in the formation.[7][8] as well as marsupial Microbiotheria.[9] It is famous for its penguin fossils, for example the two genera Archaeospheniscus and Palaeeudyptes.[10] [11] Other bird fossils include Dasornis, a genus of pseudotooth birds. There is also an abundance of trace fossils. Diplocraterion, Helminthopsis, Muensteria, Oichnus, Ophiomorpha, Skolithos, Teredolites and Zapfella have been described.[12] Over 35 species and 26 families of fish, which includes sharks, have been described from the Ypresian Cucullaea bed.[3][13] Most of the fossilized woods and flowers discovered on Seymour Islands consist of extinct species of conifer trees and lilies during warm climate.[14][15]

Meriduingulata
Astrapotheria
TaxaSpeciesPresenceAbundanceNotesImages
Antarctodon A. sobrali Telm 5 Member. MLP 08-XI-30-1, an isolated right p4 or m1. An astrapothere
Trigonostylops T. indet. An astrapothere
Litopterna
TaxaSpeciesPresenceAbundanceNotesImages
Notiolofos N. arquinotiensis A sparnotheriodontid litoptern.
N. regueroi
Victorlemoinea V. sp. A litoptern

Cetacean
TaxaSpeciesPresenceAbundanceNotesImages
Basilosaurus undetermined
Llanocetus L. denticrenatus A partial mandible with two teeth (specimen USNM 183022) and an endocast of the braincase. a toothed baleen whale.
Zygorhiza undetermined

Marsupial
Derorhynchidae
TaxaSpeciesPresenceAbundanceNotesImages
Derorhynchus[16] D. minutus[16]
Pauladelphys[16][17] P. juanjoi[16][17]
Xenostylos X. peninsularis[16]
Microbiotheria
TaxaSpeciesPresenceAbundanceNotesImages
Marambiotherium[16] M. glacialis[16] Members of Microbiotheria
Woodburnodon W. casei
Polydolopimorphia
TaxaSpeciesPresenceAbundanceNotesImages
Antarctodolops A. dailyi A polydolopimorphian metatherian.
A. mesetaense
Perrodelphys P. coquinense[16] A polydolopimorphian metatherian.
Polydolops P. dailyi A polydolopimorphian metatherian.
P. seymouriensis
P. thomasi
Pujatodon P. ektopos[18] Locality IAA 1/90. Specimen MLP 14-I-10-20, a lower left molar (m2 or m3) partially worn. A polydolopimorphian metatherian.

Other mammals
TaxaSpeciesPresenceAbundanceNotesImages
Sudamerica S. ameghinoi A gondwanathere
Meridiolestida?[19] Indeterminate A single tooth, now lost.[19]
Xenarthra? A phalanx and a partial tooth[19]

Sphenisciformes
TaxaSpeciesPresenceAbundanceNotesImages
Anthropornis A. grandis
A. nordenskjoldi[17]
Archaeospheniscus A. lopdelli
A. wimani
Delphinornis[17] D. arctowskii
D. graclis
D. larseni
Marambiornis M. exilis
Mesetaornis M. polaris
Orthopteryx O. gigas[11]
Palaeeudyptes P. antarcticus The narrow-flippered penguin.
P. gunnari [17]
P. klekowskii
Wimanornis W. seymourensis
Tonniornis T. mesetaensis
T. minimum

Pelagornithidae
TaxaSpeciesPresenceAbundanceNotesImages
Dasornis D. sp.

Amphibians
TaxaSpeciesPresenceAbundanceNotesImages
Calyptocephalella C. sp.[20] Calyptocephalellid frog

Chondrichthyes
Carcharhinidae
TaxaSpeciesPresenceAbundanceNotesImages
Scoliodon S. sp.
Hexanchidae
TaxaSpeciesPresenceAbundanceNotesImages
Heptranchias H. howellii
Hexanchus [17] H. sp.[17]
Lamnidae
TaxaSpeciesPresenceAbundanceNotesImages
Isurus I. praecursor
Lamna L. cf. nasus
Otodus O. auriculatus
Mitsukurinidae
TaxaSpeciesPresenceAbundanceNotesImages
Striatolamia S. macrota
Anomotodon A. multidenticulata
Odontaspididae
TaxaSpeciesPresenceAbundanceNotesImages
Odontaspis O. rutoti
O. winkleri
Orectolobidae
TaxaSpeciesPresenceAbundanceNotesImages
Stegostoma S. cf. varium
Pseudoginglymostoma P. cf. P. brevicaudatum
Pristiophoridae
TaxaSpeciesPresenceAbundanceNotesImages
Pristiophorus P. lanceolatus
P. laevis[21]
Squalidae
TaxaSpeciesPresenceAbundanceNotesImages
Squalus S. weltoni
S. woodburnei

Xiphiidae
TaxaSpeciesPresenceAbundanceNotesImages
Xiphiorhynchus[17] X. cf. sp.

Cephalopods
TaxaSpeciesPresenceAbundanceNotesImages
Antarcticeras A. nordenskjoeldi An enigmatic cephalopod that is either considered a descendant of the orthocerids or an oegopsid squid.
Euciphoceras E. sp. A nautiloid.

Plants
TaxaSpeciesPresenceAbundanceNotesImages
Agathoxylon A. pseudoparenchymatosum
fossilized seed of Notonuphar
Cupressinoxylon C. hallei
Notonuphar N. antarctica
Nelumbo ? Nelumbo sp.[15]
Protophyllocladoxylon P. francisiae
Phyllocladoxylon P. antarcticum
P. pooleae

See also

References
  1. Zinsmeister, Jeffrey D. Stilwell ; William J. (1992). Molluscan systematics and biostratigraphy : Lower Tertiary La Meseta Formation, Seymour Island, Antarctic Peninsula. Washington, DC: American Geophysical Union. ISBN 978-0875907703.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. Pezzetti, T.F.; KRISSEK, L.A (1986). "Re-evaluation of the Eocene La Meseta Formation of Seymour Island, AntarcticPeninsula": 75. {{cite journal}}: Cite journal requires |journal= (help)
  3. Reguero, Marcelo A.; Sergio A. Marenssi; Sergio N. Santillana (2012). "Weddellian marine/coastal vertebrates diversity from a basal horizon (Ypresian, Eocene) of the Cucullaea I Allomember, La Meseta formation, Seymour (Marambio) Island, Antarctica". Rev. Peru. Biol. 19: 275–284.
  4. Vega, Greta C.; Olalla-Tárraga, Miguel Ángel (2020), "Past changes on fauna and flora distribution", Past Antarctica, Elsevier, pp. 165–179, doi:10.1016/b978-0-12-817925-3.00009-4, ISBN 978-0-12-817925-3, retrieved 2023-09-20
  5. Pujana, Roberto R.; Santillana, Sergio N.; Marenssi, Sergio A. (January 2014). "Conifer fossil woods from the La Meseta Formation (Eocene of Western Antarctica): Evidence of Podocarpaceae-dominated forests". Review of Palaeobotany and Palynology. 200: 122–137. doi:10.1016/j.revpalbo.2013.09.001.
  6. Reguero, Marcelo A.; Marenssi, Sergio A.; Santillana, Sergio N. (May 2002). "Antarctic Peninsula and South America (Patagonia) Paleogene terrestrial faunas and environments: biogeographic relationships". Palaeogeography, Palaeoclimatology, Palaeoecology. 179 (3–4): 189–210. doi:10.1016/S0031-0182(01)00417-5.
  7. Antarctodon at Fossilworks.org
  8. Trigonostylops at Fossilworks.org
  9. Goin, F. J.; Zimicz, N.; Reguero, M. A.; Santillana, S. N.; Marenssi, S. A.; Moly, J. J. (October 2007). "New marsupial (Mammalia) from the Eocene of Antarctica, and the origins and affinities of the Microbiotheria". Revista de la Asociación Geológica Argentina. 62 (4): 597–603. ISSN 1851-8249. Retrieved 2017-02-12.
  10. Tambussi, Claudia & Acosta Hospitaleche, Carolina & Reguero, Marcelo & Marenssi, Sergio. (2006). Late Eocene penguins from West Antarctica: Systematics and biostratigraphy. Geological Society London Special Publications. 258. 145-161. 10.1144/GSL.SP.2006.258.01.11.
  11. Hospitaleche, C. A., & Reguero, M. (2011). Taxonomic status of the Eocene penguinsOrthopteryx gigasWiman, 1905 andIchtyopteryx gracilisWiman, 1905 from Antarctica. Alcheringa: An Australasian Journal of Palaeontology, 35(3), 463–466. https://doi.org/10.1080/03115518.2011.527476
  12. Uchman, Alfred; Andrzej GAŹDZICKI (2006). "New trace fossils from the La Meseta Formation (Eocene) of Seymour Island, Antarctica". Pol. Polar Res. 27: 153–170.
  13. Long, Douglas. (1992). Sharks from the La Meseta Formation (Eocene), Seymour Island, Antarctic Peninsula. Journal of Vertebrate Paleontology. 12. 11-32. 10.1080/02724634.1992.10011428.
  14. Pujana, R. R., Wilf, P., & Gandolfo, M. A. (2020). Conifer wood assemblage dominated by Podocarpaceae, early Eocene of Laguna del Hunco, central Argentinean Patagonia. PhytoKeys, 156, 81–102. https://doi.org/10.3897/phytokeys.156.54175
  15. Friis, Else M.; Iglesias, Ari; Reguero, Marcelo A.; Mörs, Thomas (2017-08-01). "Notonuphar antarctica, an extinct water lily (Nymphaeales) from the Eocene of Antarctica". Plant Systematics and Evolution. 303 (7): 969–980. doi:10.1007/s00606-017-1422-y. ISSN 2199-6881. S2CID 254058613.
  16. Goin, Francisco J. New Discoveries of "Opposum-Like" Marsupials from Antarctica (Seymour Island, Medial Eocene). OCLC 1196811246.
  17. "Antarctic Paleontological Heritage: Late Cretaceous–Paleogene vertebrates from Seymour (Marambio) Island, Antarctic Peninsula". Advances in Polar Science. 30. 20 August 2019. doi:10.13679/j.advps.2019.0015.
  18. Francisco J. Goin; Emma C. Vieytes; Javier N. Gelfo; Laura Chornogubsky; Ana N. Zimicz; Marcelo A. Reguero (2020). "New metatherian mammal from the early Eocene of Antarctica". Journal of Mammalian Evolution. 27 (1): 17–36. doi:10.1007/s10914-018-9449-6. S2CID 91932037.
  19. Gelfo, Javier N.; Goin, Francisco J.; Bauzá, Nicolás; Reguero, Marcelo (30 September 2019). "The fossil record of Antarctic land mammals: Commented review and hypotheses for future research". Advances in Polar Science: 274–292. doi:10.13679/j.advps.2019.0021.
  20. Mörs, Thomas; Reguero, Marcelo; Vasilyan, Davit (2020-04-23). "First fossil frog from Antarctica: implications for Eocene high latitude climate conditions and Gondwanan cosmopolitanism of Australobatrachia". Scientific Reports. 10 (1): 5051. Bibcode:2020NatSR..10.5051M. doi:10.1038/s41598-020-61973-5. ISSN 2045-2322. PMC 7181706. PMID 32327670.
  21. Engelbrecht; Mörs; Reguero; Kriwet, Andrea; Thomas; Marcelo A.; Jürgen (May 2017). "A new saw shark, Pristiophorus laevis, from the Eocene of Antarctica with comments on Pristiophorus lanceolatus". Historical Biology. 29 (6): 841–853. doi:10.1080/08912963.2016.1252761. PMC 5447807. PMID 28579693.{{cite journal}}: CS1 maint: multiple names: authors list (link)

Further reading
  • R. A. Askin. 1997. Eocene-?Earliest Oligocene terrestrial palynology of Seymour Island, Antarctica. : 993-996. The Antarctic Region: Geological Evolution and Processes 993-996
  • M. A. Bitner. 1991. A supposedly new brachiopod from the Paleogene of Seymour Island, West Antarctica. Polish Polar Research 12(2):243-246
  • D. B. Blake and R. B. Aronson. 1998. Eocene stelleroids (Echinodermata) at Seymour Island, Antarctic Peninsula. Journal of Paleontology 72(2):339-353
  • M. Bond, M. A. Reguero, S. F. Vizcaino and S. A. Marenssi. 2006. A new 'South American ungulate' (Mammalia: Litopterna) from the Eocene of the Antarctic Peninsula. Geological Society, London, Special Publications 258:163-176
  • J. A. Case. 1988. Paleogene floras from Seymour Island, Antarctic Peninsula. Geology and Paleontology of Seymour Island Antarctic Peninsula 523-540
  • M. M. Cenizo. 2012. Review of the putative Phorusrhacidae from the Cretaceous and Paleogene of Antarctica: new records of ratites and pelagornithid birds. Polish Polar Research 33(3):225-244
  • A. L. Cione, M. de las Mercedes Azpelicueta, and D. R. Bellwood. 1995. An oplegnathid fish from the Eocene of Antarctica. Palaeontology 37(4):931-940
  • A. L. Cione and M. A. Reguero. 1994. New records of the sharks Isurus and Hexanchus from the Eocene of Seymour Island, Antarctica. Proceedings of the Geologists' Association 105:1-14
  • J. Kriwet. 2005. Additions to the Eocene Selachian Fauna of Antarctica with Comments on Antarctic Selachian Diversity. Journal of Vertebrate Paleontology 25(1):1-7
  • S. A. Marenssi, M. A. Regeuro, S. N. Santillana and S. F. Vizcaino. 1994. Eocene land mammals from Seymour Island, Antarctica: palaeobiogeographical implications. 6(1):3-15
  • I. Poole, A. M. W. Mennega, and D. J. Cantrill. 2003. Valdivian ecosystems in the Late Cretaceous and Early Tertiary of Antarctica: further evidence from myrtaceous and eucryphiaceous fossil wood. Review of Palaeobotany and Palynology 124:9-27
  • R. R. Pujana, S. N. Santillana, and S. A. Marenssi. 2014. Conifer fossil woods from the La Meseta Formation (Eocene of Western Antarctica): Evidence of Podocarpaceae-dominated forests. Review of Palaeobotany and Palynology (200)122-137
  • S. F. Vizcaino, M. A. Reguero, S. A. Marenssi and S. N. Santillana. 1997. New land mammal-bearing localities from the Eocene La Meseta Formation, Seymour Island, Antarctica. The Antarctic Region: Geological Evolution and Processes 997-1000
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.