Ampelosaurus

Ampelosaurus is a titanosaurian sauropod dinosaur from the Late Cretaceous of southern France. Named in 1995 by Jean Le Loeuff, its type species Ampelosaurus atacis derives from abundant remains found in the Upper Aude Valley. The genus name combines the Ancient Greek for “vine” and saurus (“lizard”), referencing the vineyards near the type locality, while the species name honours the River Aude (Atax in Latin). Dated to the early Maastrichtian, around 71–70 million years ago, Ampelosaurus inhabited the Ibero–Armorican Island and represents one of the best-known sauropods from France due to extensive fossil material and multiple excavations over several decades.
Although historically regarded as the only titanosaur present at its primary locality, recent studies indicate that more than one titanosaur species coexisted there. This has introduced considerable taxonomic complexity and the ongoing reassessment of material previously attributed to Ampelosaurus atacis.

Discovery and Naming

Upper Aude Valley (France)

Ampelosaurus is principally known from the Marnes Rouges Inférieures Formation near Campagne-sur-Aude in the Aude department of Occitania. These deposits reflect a floodplain system with numerous fluvial channels active during the early Maastrichtian.
Dinosaur remains from the Upper Aude Valley were first documented in 1877 by Paul Gervais from material found at Fa, but the discoveries remained sporadic. Renewed interest began in 1982 when local collectors Pierre Clottes and Christian Raynaud rediscovered fossiliferous sites following the chance finding of a bone in 1981. Their initial surface collecting yielded caudal vertebrae and limb bones.
Systematic excavations commenced in 1989 at the Bellevue farm site. Over 500 bones recovered from successive campaigns formed the basis for Le Loeuff’s naming of Ampelosaurus atacis in 1995. The holotype included articulated thoracic vertebrae and associated material, while four osteoderms described in 1994 were also attributed to the species. A more complete description appeared in 2005, incorporating cranial material including a braincase and mandible.
In 2001, a relatively complete skeleton of a young adult about 10 m long, nicknamed “Eva,” was discovered. Further excavations through 2006 yielded an almost complete disarticulated skull, parts of which are displayed in the Dinosauria Museum. In 2007, remains of an even larger individual—including a femur 1.20 m long—were unearthed.

Taxonomic Revisions and New Titanosaurs

For more than two decades, fossils at Bellevue were attributed exclusively to Ampelosaurus. Variation in limb proportions was interpreted as intraspecific variability. However, a morphometric study in 2012 suggested the presence of three titanosaur femur morphotypes, one tentatively linked to Lirainosaurus. Later work found these remains incompatible with that genus, and in 2021 comparisons indicated closer affinities to Garrigatitan from Provence.
Recent research confirms the presence of at least one additional titanosaur species at Bellevue. A comprehensive reassessment presented in 2023 supports the existence of a new taxon, the description of which is in progress. As a result, many isolated bones traditionally assigned to Ampelosaurus atacis are now regarded as taxonomically uncertain.

Purported Remains from Other Localities

Reports of Ampelosaurus from beyond the Upper Aude Valley have not withstood close scrutiny:

• Ariege (Grès de Labarre): Initial suggestions of multiple titanosaurs, including Ampelosaurus, remain unconfirmed; material is too fragmentary for precise assignment.
• Hérault (Cruzy area): Teeth and postcranial remains once attributed to Ampelosaurus were later shown to belong to a new, unnamed titanosaur.
• Lo Hueco (Cuenca, Spain): Teeth resembling those of Ampelosaurus were later reinterpreted. A braincase tentatively assigned to Ampelosaurus sp. in 2013 was reclassified as belonging to Lohuecotitan following its formal description in 2016.

Despite abundant titanosaur remains at Lo Hueco, none has yet been conclusively identified as Ampelosaurus.

Description

Ampelosaurus possessed the typical sauropod body plan: a long neck and tail, a massive torso, and columnar limbs. Distinctive among titanosaurs, it carried bony armour in the form of osteoderms, which show three morphological types—plate-like, bulbous, and spined. The known osteoderms range from 25 to 28 cm in length.
Size estimates vary, but Ampelosaurus was not an insular dwarf, unlike some other titanosaurs of the Ibero–Armorican domain. Early estimates suggested a moderate size; more recent analyses, including those based on the large femur MDE-C3-174, propose a length of approximately 15 metres and a mass around 10 tonnes for the largest individuals.
Histological studies indicate somewhat reduced growth rates, consistent with ecological pressures associated with island environments, although these factors did not produce the extreme dwarfism observed in some related taxa.

Palaeoenvironment and Palaeobiogeography

Ampelosaurus inhabited the Ibero–Armorican Island, a Late Cretaceous landmass comprising present-day France and the Iberian Peninsula. The floodplain habitats of the Marnes Rouges Inférieures Formation supported a diverse ecosystem, including crocodilians, turtles, and other dinosaurs.
Its apparent coexistence with additional titanosaurs suggests niche partitioning or staggered temporal ranges, though further taxonomic revision is required to clarify species boundaries.

Scientific Importance

Ampelosaurus is one of the most comprehensively known French dinosaurs due to extensive fossil material, ongoing excavation, and decades of study. Its osteoderms, island-related growth patterns, and the taxonomic complexity of the Bellevue assemblage make it a focal point in research on titanosaur diversity, European Late Cretaceous vertebrate faunas, and insular evolutionary processes.