Land vertebrate faunachrons (LVFs) are biochronological units used to correlate and date terrestrial sediments and fossils based on their tetrapod faunas.[1] First formulated on a global scale by Spencer G. Lucas in 1998, LVFs are primarily used within the Triassic Period (252 - 201 Ma),[1] though Lucas later designated LVFs for other periods as well.[2] Eight worldwide LVFs are defined for the Triassic. The first two earliest Triassic LVFs, the Lootsbergian and Nonesian, are based on South African synapsids and faunal assemblage zones estimated to correspond to the Early Triassic. These are followed by the Perovkan and Berdyankian, based on temnospondyl amphibians and Russian assemblages estimated to be from the Middle Triassic. The youngest four Triassic LVFs, the Otischalkian, Adamanian, Revueltian, and Apachean, are based on aetosaur and phytosaur reptiles common in the Late Triassic of the southwestern United States.[1][3][4]
The LVF system, though widely used, is also a controversial application of biostratigraphy, as many Triassic tetrapods are rife with complications which endanger their utility as index fossils. Limited occurrences, inaccurate age estimates, overlapping LVF faunas, or taxonomic disagreement may jeopardize global correlations between Triassic tetrapods. This could render some LVFs as misleading assessments of Triassic faunal change through time.[5][6][7][8] Regardless, Late Triassic phytosaurs are considered to have strong biostratigraphic utility even among detractors of Lucas's system.[9]
^Lucas, Spencer G. (2005). "Permian Tetrapod Faunachrons". New Mexico Museum of Natural History and Science Bulletin. 30: 197–201.
^Cite error: The named reference :4 was invoked but never defined (see the help page).
^Cite error: The named reference :7 was invoked but never defined (see the help page).
^Cite error: The named reference :9 was invoked but never defined (see the help page).
^Cite error: The named reference :10 was invoked but never defined (see the help page).
^Rayfield, Emily J.; Barrett, Paul M.; Milner, Andrew R. (2009-03-12). "Utility and validity of Middle and Late Triassic 'land vertebrate faunachrons'". Journal of Vertebrate Paleontology. 29 (1): 80–87. doi:10.1671/039.029.0132. ISSN 0272-4634. S2CID 86502146.
^Irmis, Randall B.; Martz, Jeffrey W.; Parker, William G.; Nesbitt, Sterling J. (March 2010). "Re-evaluating the correlation between Late Triassic terrestrial vertebrate biostratigraphy and the GSSP-defined marine stages" (PDF). Albertiana. 38: 40–53.
^Cite error: The named reference :8 was invoked but never defined (see the help page).
and 30 Related for: Triassic land vertebrate faunachrons information
Landvertebratefaunachrons (LVFs) are biochronological units used to correlate and date terrestrial sediments and fossils based on their tetrapod faunas...
the Triassic. Geology portal Paleontology portal Geologic time scale List of fossil sites (with link directory) Triassiclandvertebratefaunachrons Phylloceratina...
(2009-03-12). "Utility and validity of Middle and Late Triassic 'landvertebratefaunachrons'". Journal of Vertebrate Paleontology. 29 (1): 80–87. Bibcode:2009JVPal...
but will likely be based on conodonts. The late Triassic is also divided into land-vertebratefaunachrons. These are, from oldest to youngest, the Berdyankian...
Milner: Utility and Validity of Middle and Late Triassic 'LandVertebrateFaunachrons'. In: Journal of Vertebrate Paleontology. Vol. 29, 2009, No. 1, pp. 80–87...
of the Late TriassicLandVertebrate "Faunachrons" of Western North America: Recommendations for Codifying Nascent Systems of Vertebrate Biochronology"...
species of giant horsetails) and Ladinian-age palynomorphs. Triassiclandvertebratefaunachrons Erfurt Formation, contemporaneous fossiliferous formation...
arch. Correlations and ages based on Spencer G. Lucas' LandVertebrateFaunachrons. The faunachrons are based on first and last appearances of phytosaurs...
(2009). "Utility and validity of Middle and Late Triassic 'landvertebratefaunachrons'". Journal of Vertebrate Paleontology. 29 (1): 80–87 1245–1266. Bibcode:2009JVPal...
of Namibia Geology of South Africa Santa Maria Formation Triassiclandvertebratefaunachrons Hancox, P.J.; Neveling, J.; Rubidge, B.S. (2020-06-01). "Biostratigraphy...
(2009-03-12). "Utility and validity of Middle and Late Triassic 'landvertebratefaunachrons'". Journal of Vertebrate Paleontology. 29 (1): 80–87. Bibcode:2009JVPal...
primarily via terrestrial tetrapod biostratigraphy (see Triassiclandvertebratefaunachrons) Geologic time scale – System that relates geologic strata...
ventricular failure, a heart condition Land-vertebratefaunachron, a biochronology system primarily used for Triassic tetrapods Lineated valley fill, a geologic...
of the Upper Triassic Redonda Formation East-central New Mexico: The Characteristic Assemblage of the Apachean Land-vertebrateFaunachron". Bulletin of...
Paleontology portal List of synapsids Triassiclandvertebratefaunachrons Keyser, A. W., & Smith, R. M. H. (1978). Vertebrate biozonation of the Beaufort Group...
are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned...
tetrapod during the Upper Triassic, present in most locations where phytosaurs are absent. In the controversial LandVertebrateFaunachron system, Hyperodapedon...
REDONDA FORMATION (UPPER TRIASSIC CHINLE GROUP) VERTEBRATE FAUNA AND ITS IMPACT ON THE APACHEAN LAND-VERTEBRATEFAUNACHRON". Retrieved 2015-02-27. Spielmann...
stage of the Late Triassic. The locality from which it was named after also lends its name to the Adamanian LVF (landvertebratefaunachron). Heckert, A....
the Colorado City Formation form the basis of the Otischalkian LandVertebrateFaunachron (LVF), which is defined by the first appearance of Parasuchus...
biostratigraphic utility as an index fossil of the St. Johnsian sub-LVF (land-vertebratefaunachron). The type species, Krzyzanowskisaurus hunti, was reevaluated...
of the Upper Triassic Redonda formation, East-Central New Mexico: the characteristic assemblage of the Apachean land-vertebratefaunachron. New Mexico...
of the Upper Triassic Redonda Formation, east-central New Mexico; the characteristic assemblage of the Apachean land-vertebratefaunachron". New Mexico...
Global Information