Plateosaurus trossingensis

Plateosaurus trossingensis was an early sauropodomorph: a comparatively large, long-necked herbivorous dinosaur from before the age of giant quadrupedal sauropods. It carried a small skull on a flexible neck, a deep body above powerful hind limbs and a long muscular tail. The shorter forelimbs ended in mobile grasping hands with an enlarged inner claw. Digital skeletal studies indicate that the palms could not rotate into the flat, forward-facing position needed for ordinary quadrupedal walking, making Plateosaurus an obligate biped despite many older four-footed reconstructions.

Its fossils occur between approximately 214 and 204 million years ago. Values shown here are approximate and reflect the current curated seed dataset.

Holotype SMNS 13200 preserves almost the entire skeleton, including a largely articulated skull about 34 centimetres long. The jaw carried numerous small, coarsely serrated leaf-shaped teeth suited to cropping plant material. Five-fingered hands remained free for grasping, with a large thumb claw whose exact function is unknown. Robust hind limbs supported the body, and powerful tail muscles helped balance and propel the animal. Some parts of the holotype were restored in plaster during early preparation, but the 2024 redescription explicitly distinguishes restoration from original bone.

• Small, deep-sided skull with a downturned front of the lower jaw
• Numerous leaf-shaped teeth with coarse serrations
• Long flexible neck and a deep, barrel-shaped torso
• Five-fingered grasping hands with an enlarged thumb claw
• Forearms and wrists unable to place the palms flat for normal quadrupedal walking
• Powerful hind limbs supporting an obligately bipedal stance
• Long muscular tail with chevrons protecting blood vessels beneath the vertebrae

Eberhard Fraas recovered the almost complete skeleton SMNS 13200 from the lower bonebed at Trossingen in 1912 and named Plateosaurus trossingensis in 1913. Friedrich von Huene produced its first full anatomical description in 1926. The genus Plateosaurus had originally been named by Hermann von Meyer in 1837 for fragmentary P. engelhardti material, creating a long-running nomenclatural problem. In 2019 the International Commission on Zoological Nomenclature designated P. trossingensis as the genus’s type species, tying the name Plateosaurus to diagnostic material. A modern, specimen-based redescription of SMNS 13200 followed in 2024.

Discovery credit: Eberhard Fraas.

Naming authors: Eberhard Fraas.

The Trossingen Formation records broad, seasonally wet and dry lowlands crossed by shallow drainage systems. Mudstone bonebeds accumulated over multiple events rather than one instantaneous catastrophe. Plateosaurus browsed among seed ferns, conifers and other Triassic vegetation alongside smaller reptiles and archosaurs. Swiss finds from Frick come from a semi-arid basin with flood-prone mud flats that could become dangerous natural traps.

Plateosaurus was primarily a terrestrial browser that cropped vegetation with its serrated teeth while the hands remained available to pull branches or manipulate food. The enlarged thumb claw may have helped in feeding or defence, but no direct trace selects one use. Bone histology shows unusually flexible growth: animals of similar age could differ greatly in size, and the age at which growth slowed varied between individuals. Healed tail injuries demonstrate that some animals survived substantial trauma; competing explanations include accidents in mud, tendon strain, social impacts and predator attacks.

• In 2019 P. trossingensis replaced the fragmentary P. engelhardti as the official type species of Plateosaurus.
• Almost 15% of the Plateosaurus individuals examined in a 2024 study had damage to the chevron bones beneath the tail.
• The nearly eight-metre Swiss skeleton ‘Teoplati’ preserves a severe chronic shoulder infection and is displayed in the pose in which it was excavated.
• The holotype’s skull is only about 34 centimetres long even though the complete animal was several metres in length.

A research repository is not necessarily a public exhibit. Loan and display status can change, so check with the institution before visiting.

1. 01
   The Paleobiology Database

   Open source
2. 02
   Osteological redescription of the holotype of Plateosaurus trossingensis and its phylogenetic implications

   Joep Schaeffer · Journal of Systematic Palaeontology · 2024

   Open source
3. 03
   Opinion 2435: Plateosaurus Meyer, 1837—new type species designated

   International Commission on Zoological Nomenclature · Bulletin of Zoological Nomenclature · 2019

   Open source
4. 04
   The Digital Plateosaurus I: Body Mass, Mass Distribution and Posture Assessed Using CAD and CAE on a Digitally Mounted Complete Skeleton

   Heinrich Mallison · Palaeontologia Electronica · 2010

   Open source
5. 05
   Developmental Plasticity in the Life History of a Prosauropod Dinosaur

   P. Martin Sander, Nicole Klein · Science · 2005

   Open source
6. 06
   Paleobiological implications of chevron pathology in the sauropodomorph Plateosaurus trossingensis from the Upper Triassic of SW Germany

   Joep Schaeffer, Ewan Wolff, Florian Witzmann and 3 coauthors · PLOS ONE · 2024

   Open source
7. 07
   New insights into one of Europe’s oldest dinosaurs

   State Museum of Natural History Stuttgart · 2024

   Open source
8. 08
   Oldest Diagnosis of Bone Infection in a Dinosaur

   University of Zurich · 2025

   Open source