Ladinian

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System Series Stage Age (Ma)
Jurassic Early Hettangian younger
Triassic Late Rhaetian 201.3–208.5
Norian 208.5–~228
Carnian ~228–~235
Middle Ladinian ~235–~242
Anisian ~242–247.2
Early Olenekian 247.2–251.2
Induan 251.2–252.2
Permian Lopingian Changhsingian older
Subdivision of the Triassic system
according to the IUGS, as of July 2012.

The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between ~242 Ma and ~235 Ma (million years ago).[1] The Ladinian was preceded by the Anisian and succeeded by the Carnian (part of the Upper or Late Triassic).[2]

The Ladinian is coeval with the Falangian Chinese regional stage.

Stratigraphic definitions

The Ladinian was established by Austrian geologist Alexander Bittner in 1892. Its name comes from the Ladin people that live in the Italian Alps (in the Dolomites, then part of Austria-Hungary).

The base of the Ladinian stage is defined as the place in the stratigraphic record where the ammonite species Eoprotrachyceras curionii first appears. The global reference profile for the base (the GSSP) is at an outcrop in the river bed of the Caffaro river at Bagolino, in the province of Brescia, northern Italy.[3] The top of the Ladinian (the base of the Carnian) is at the first appearance of ammonite species Daxatina canadensis.

The Ladinian is sometimes subdivided into two subages or substages, the Fassanian (early or lower) and the Longobardian (late or upper). The Ladinian contains four ammonite biozones, which are evenly distributed among the two substages:

  • zone of Frechites regoledanus
  • zone of Protrachyceras archelaus
  • zone of Protrachyceras gredleri
  • zone of Eoprotrachyceras curionii

Palaeontology

Many Ladinian and Carnian vertebrates have been discovered in the paleorrota in Brazil: Rhynchosaurs, thecodonts, exaeretodonts, Staurikosaurus, Guaibasaurus, Saturnalia tupiniquim, Sacisaurus, Unaysaurus, and many others. Paleorrota lies within the Santa Maria Formation and the Caturrita Formation.

Vertebrates of Ladinian age include:

†Dinosauromorphs (non-dinosaurian)

†Non-dinosaurian dinosauromorphs of the Ladinian
Taxa Presence Location Description Images
Chañares Formation, Argentina
Lagosuchus
Argentina

†Placodonts

Placodonts of the Ladinian
Taxa Presence Location Description Images
Cyamodus
Paraplacodus

†Therapsids (non-mammalian)

†Non-mammalian Therapsids of the Ladinian
Taxa Presence Location Description Images
Exaeretodon

See also

References

Notes

  1. ↑ According to Gradstein et al. (2004). Brack et al. (2005) give 241 to 235 Ma
  2. ↑ For a detailed geologic timescale see Gradstein et al. (2004)
  3. ↑ The GSSP was established by Brack et al. (2005)

Literature

  • Bittner, A.; 1892: Was ist norisch?, Jahrbuch der kaiserlich-königlichen geologischen Reichsanstalt 42(3), pp. 387–396. (German)
  • Brack, P.; Rieber, H.; Nicora, A. & Mundil, R.; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale, Episodes 28(4), pp. 233–244.
  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.

External links

Triassic Period
Lower/Early Triassic Middle Triassic Upper/Late Triassic
Induan |Olenekian Anisian | Ladinian Carnian | Norian
Rhaetian
 
In horizontal bars are eras; in left column are periods; right column: bold are epochs; not bold not italic are ages; italic are chrons:
 
Triassic
(250 – 200 Mya)
Jurassic
(200 – 144 Mya)
Cretaceous
(145 – 65 Mya)
kya = thousands years ago. Mya = millions years ago. * Not officially recognized by the I.C.S.
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