Ladinian

The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 242 Ma and ~237 Ma (million years ago).[2] The Ladinian was preceded by the Anisian and succeeded by the Carnian (part of the Upper or Late Triassic).[3]

System/
Period
Series/
Epoch
Stage/
Age
Age (Ma)
Jurassic Lower/
Early
Hettangian younger
Triassic Upper/
Late
Rhaetian 201.3 ~208.5
Norian ~208.5 ~227
Carnian ~227 ~237
Middle Ladinian ~237 ~242
Anisian ~242 247.2
Lower/
Early
Olenekian 247.2 251.2
Induan 251.2 251.902
Permian Lopingian Changhsingian older
Subdivision of the Triassic system
according to the ICS, as of 2020.[1]
Monte San Giorgio preserves many exceptionally preserved Ladinian aged vertebrate fossils

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 or the first appearance of the conodont Budurovignathus praehungaricus. 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.[4] 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:

Ladinian life

Many Ladinian and Carnian vertebrates have been discovered in the Paleorrota Geopark 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:

Actinopterygians

Actinopterygii of the Ladinian
Taxa Presence Location Description Images
Triassic China, Switzerland, Italy A non-neopterygian
Middle Triassic Switzerland
Middle Triassic Switzerland, Italy
Middle Triassic Italy, Switzerland, China A neopterygian
Middle Triassic to Late Triassic Switzerland, Italy The earliest teleosteomorph (modern ray-fin)
Middle Triassic to Early Jurassic Switzerland, Italy A non-neopterygian
Triassic China, Switzerland, Italy A non-neopterygian
Middle Triassic to Late Triassic China The earliest gliding fish

Coelacanths

Actinistia of the Ladinian
Taxa Presence Location Description Images
Middle Triassic Spain A coelacanth
Middle Triassic Switzerland A coelacanth
Middle Triassic Germany A coelacanth
Middle Triassic Switzerland, Italy A coelacanth

†Temnospondyls

Temnospondyli of the Ladinian
Taxa Presence Location Description Images
Upper Muschelkalk beds, Germany A mastodonsaurid temnospondyl.
Russia A mastodonsaurid temnospondyl.
Middle Triassic Germany A mastodonsaurid.
Lower Keuper, Staffordshire, England. A stenotosaurid temnospondyl.
Middle Triassic Germany A trematosaurid temnospondyl.

†Chroniosuchians

Chroniosuchia of the Ladinian
Taxa Presence Location Description Images
Middle Triassic Germany A chroniosuchian reptiliomorph
Komi Republic, Urals, Russia A chroniosuchian reptiliomorph.

†Tanystropheids

Tanystropheids of the Ladinian
Taxa Presence Location Description Images
Muschelkalk, Spain Cosesaurus is a genus of archosauromorph reptiles, likely a juvenile belonging to the family Tanystropheidae.
Falang Formation, southern China. Fuyuansaurus is an extinct genus of archosauromorph reptiles, probably part of Tanystropheidae.
late Anisian to Ladinian China, Switzerland
Middle Triassic to Late Triassic China, Europe

Archosaurs

Archosaurs of the Ladinian
Taxa Presence Location Description Images
Orenburg Oblast, Russia A basal predatory archosauriform, a member of Erythrosuchidae.
Bashkortostan, Russia An indeterminate archosaur, possibly a rauisuchid.
Lower Santa Maria Formation, Paleorrota Geopark, Brazil. A member of aphanosauria, basal relatives of dinosaurs and pterosaurs.
Tongchuan Formation, Shanxi, China Yonghesuchus was not considered to be a crown-group archosaur, but rather a closely related advanced archosauriform, but in most recent analyses, Yonghesuchus has been recovered as in a well supported clade, the Gracilisuchidae within the Pseudosuchia, along with Gracilisuchus and Turfanosuchus.
All across Europe Zanclodon is the name formally used for fossil material that might actually belongs to at least two genera of dinosaur from the Late Triassic among other genera.

Suchians

Suchians of the Ladinian
TaxaPresenceLocationDescriptionImages
Erfurt Formation, Germany
Santa Maria Formation, Brazil
European Russia
late Ladinian or Carnian Clark locality, Wyoming
Batung Formation, Hunan, China
late Ladinian or early Carnian Chañares Formation, Argentina
Santa Maria Formation, Brazil
Switzerland, Italy

†Thalattosaurs

Thalattosauria of the Ladinian
Taxa Presence Location Description Images
Middle Triassic to Late Triassic China An askeptosauroid
Middle Triassic to Late Triassic Canada A thalattosauroid
Middle Triassic to Late Triassic China A thalattosauroid

†Sauropterygians

†Pistosaurs

Pistosauria of the Ladinian
Taxa Presence Location Description Images
Middle Triassic France, Germany A sauropterygian

†Nothosaurs

Nothosauroidea of the Ladinian
Taxa Presence Location Description Images
Middle Triassic Italy, Switzerland Possibly a synonym of Lariosaurus.
  • Lariosaurus
    • Lariosaurus balsami
    • Lariosaurus curionii
    • Lariosaurus valceresii
    • Lariosaurus xingyiensis
Middle Triassic Europe, China A sauropterygian
Middle Triassic to Late Triassic Europe, China A sauropterygian
Anisian-Ladinian boundary Switzerland Possibly a species of Lariosaurus.
Middle Triassic Germany, France A sauropterygian

†Pachypleurosaurs

Pachypleurosauria of the Ladinian
Taxa Presence Location Description Images
Middle Triassic China A sauropterygian
Middle Triassic Italy, Switzerland A sauropterygian
Earliest Ladinian Switzerland A sauropterygian
Middle Triassic China A sauropterygian

†Placodonts

Placodonts of the Ladinian
Taxa Presence Location Description Images
Middle Triassic Germany A sauropterygian
Middle Triassic China A sauropterygian
Middle Triassic to Late Triassic Hungary A sauropterygian
Middle Triassic Italy A sauropterygian
Middle Triassic Egypt; Israel A sauropterygian

†Ichthyopterygians

Ichthyopterygia of the Ladinian
Taxa Presence Location Description Images
Middle Triassic Switzerland An elongate ichthyosaur
Middle Triassic Switzerland, Italy An ichthyosaur
Early Triassic to Middle Triassic Austria, Italy An ichthyosauriform with button-like teeth

Therapsids

Therapsids of the Ladinian
Taxa Presence Location Description Images
Paleontological Site Chiniquá, Brazil
Ladinian-Carnian Santa Maria Formation, Brazil

Santa Maria Formation, Brazil and Omingonde Formation, Namibia

References

Notes

  1. "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. 2020.
  2. http://www.stratigraphy.org/index.php/ics-chart-timescale
  3. For a detailed geologic timescale see Gradstein et al. (2004)
  4. 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. (in 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.

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