La Meseta Formation

The La Meseta Formation is a sedimentary sequence deposited during the Eocene.[2] The formation is found on Seymour Island, Antarctica.

La Meseta Formation
Stratigraphic range: Eocene
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]

Paleobiota

La Meseta Formation is extremely rich in fossils. Among mammals, the meridiungulata Antarctodon and Trigonostylops have been found in the formation.[4][5] as well as marsupial Microbiotheria.[6] It is famous for its penguin fossils, for example the two genera Archaeospheniscus and Palaeeudyptes.[7] [8] 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.[9] Over 35 species and 26 families of fish, which includes sharks, have been described from the Ypresian Cucullaea bed.[3][10] Most of the fossilized woods and flowers discovered on Seymour Islands consist of extinct species of conifer trees and lilies during warm climate.[11][12]

Astrapotheria
TaxaSpeciesPresenceAbundanceNotesImages
Antarctodon A. sobrali
Trigonostylops T. indet.
Litopterna
TaxaSpeciesPresenceAbundanceNotesImages
Notiolofos N. arquinotiensis
N. regueroi
Victorlemoinea V. sp.

Cetacea

TaxaSpeciesPresenceAbundanceNotesImages
Basilosaurus undetermined
Llanocetus L. denticrenatus
Llanocetus denticrenatus skull
Zygorhiza undetermined
Derorhynchidae
TaxaSpeciesPresenceAbundanceNotesImages
Derorhynchus[13] D. minutus[13]
Pauladelphys[13][14] P. juanjoi[13][14]
Xenostylos Xenostylos peninsularis[13]


Marsupialia
TaxaSpeciesPresenceAbundanceNotesImages
Marambiotherium[13] M. glacialis[13]
Woodburnodon W. casei
Polydolopimorphia
TaxaSpeciesPresenceAbundanceNotesImages
Antarctodolops A. dailyi
A. mesetaense
Perrodelphys P. coquinense[13]
Polydolops P. dailyi
P. seymouriensis
P. thomasi
Pujatodon P. ektopos[15]

Sudamericidae

TaxaSpeciesPresenceAbundanceNotesImages
Sudamerica S. ameghinoi

Sphenisciformes

TaxaSpeciesPresenceAbundanceNotesImages
Anthropornis A. grandis
A. nordenskjoldi[14]
Size comparison of the Anthropornis nordenskjoeldi
Archaeospheniscus A. lopdelli
A. wimani
Delphinornis[14] D. arctowskii
D. graclis
D. larseni
Marambiornis M. exilis
Mesetaornis M. polaris
Orthopteryx O. gigas[8]
Palaeeudyptes P. antarcticus
Huxley’s original illustration of the fossil of an ankle bone from Palaeeudyptes antarcticus described in 1859.

The restoration of Palaeeudyptes Klekowskii
P. gunnari [14]
P. klekowskii
Wimanornis W. seymourensis
Tonniornis T. mesetaensis
T. minimum

Pelagornithidae

TaxaSpeciesPresenceAbundanceNotesImages
Dasornis D. sp.

    Amphibians

    TaxaSpeciesPresenceAbundanceNotesImages
    Calyptocephalella C. sp.[16]
    Carcharhinidae
    TaxaSpeciesPresenceAbundanceNotesImages
    Scoliodon Scoliodon sp.
    Hexanchidae
    TaxaSpeciesPresenceAbundanceNotesImages
    Heptranchias H. howellii
    Hexanchus [14] H. sp.[14]
    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[17]
    Squalidae
    TaxaSpeciesPresenceAbundanceNotesImages
    Squalus S. weltoni
    S. woodburnei

    Xiphiidae

    TaxaSpeciesPresenceAbundanceNotesImages
    Xiphiorhynchus[14] X. cf. sp.

    Plants

    TaxaSpeciesPresenceAbundanceNotesImages
    Agathoxylon A. pseudoparenchymatosum
    Cupressinoxylon C. hallei
    Notonuphar N. antarctica
    fossilized seed of Notonuphar
    Nelumbo ? Nelumbo sp.[12]
    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.
    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. Antarctodon at Fossilworks.org
    5. Trigonostylops at Fossilworks.org
    6. 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.
    7. 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.
    8. 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
    9. Uchman, Alfred; Andrzej GAŹDZICKI (2006). "New trace fossils from the La Meseta Formation (Eocene) of Seymour Island, Antarctica". Pol. Polar Res. 27: 153–170.
    10. Long, Douglas. (1992). Sharks from the La Meseta Formation (Eocene), Seymour Island, Antarctic Peninsula. Journal of Vertebrate Paleontology - J VERTEBRATE PALEONTOL. 12. 11-32. 10.1080/02724634.1992.10011428.
    11. 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
    12. 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.
    13. Goin, Francisco J. New Discoveries of "Opposum-Like" Marsupials from Antarctica (Seymour Island, Medial Eocene). OCLC 1196811246.
    14. "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.
    15. 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.
    16. 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. doi:10.1038/s41598-020-61973-5. ISSN 2045-2322. PMC 7181706. PMID 32327670.
    17. 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
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