Description and Classification

Like other sauropods, Bothriospondylus was a large, four-legged plant-eater with a long neck, a massive body, and a long tail that likely acted as a counterbalance. Its legs were strong and pillar-like to support its considerable weight. Due to the incomplete nature of its fossils, precise size estimates are difficult, but it was undoubtedly a very large animal, possibly reaching lengths comparable to other European Jurassic sauropods, perhaps around 15 to 20 meters (approximately 50 to 65 feet).

Bothriospondylus belongs to the group Sauropoda, which includes the largest land animals ever to have lived. Its classification within Sauropoda has been a subject of debate. Historically, it was often linked to the Brachiosauridae family due to some similarities in its vertebrae. More recent analyses, considering its features, might place it more broadly within the Macronaria group, which includes brachiosaurids and titanosaurs. The type species is Bothriospondylus suffossus. Over the years, several other species were assigned to this genus, but most of these are now considered to belong to different dinosaurs or are also of dubious validity.

Distinguishing Features

The features originally used to define Bothriospondylus are mostly found in its vertebrae. However, many of these characteristics are now known to be common among various sauropod groups, contributing to its status as a doubtful name. The features historically noted include:

• Deep hollow spaces or cavities, known as pleurocoels, on the sides of the centra (the main body) of its back vertebrae. These were likely filled with air sacs to lighten the skeleton.
• A complex, spongy internal structure within the vertebrae, also related to air sacs, a feature common in many sauropods for reducing weight without sacrificing strength.
• The vertebrae in the back were described as opisthocoelous, meaning they were concave (curved inward) on their rear surface and convex (curved outward) on their front surface, allowing for flexibility in the spine.

The main challenge is that these features are not unique enough to confidently distinguish Bothriospondylus from other sauropods known from similarly incomplete remains from the same time and region.

Paleoenvironment and Diet

Bothriospondylus lived in what is now Europe during the Late Jurassic period. The specific rock formations where its fossils have been found, such as the Kimmeridge Clay in England, suggest a varied environment. While some of these areas were near shallow seas, Bothriospondylus itself would have lived on land, likely in lush, vegetated areas like forests, open woodlands, or fern-covered plains. The climate during the Late Jurassic was generally warm and humid, supporting a rich diversity of plant life.

As a sauropod, Bothriospondylus was a herbivore. Its long neck would have allowed it to reach high into the treetops to feed on leaves and branches from conifers, cycads, and tree ferns. Like other sauropods, it probably consumed vast quantities of plant material daily to sustain its large body. It shared its environment with other dinosaurs, including other types of sauropods, stegosaurs like Dacentrurus, and various theropod predators.

Significance and Ongoing Research

Bothriospondylus is significant as one of the sauropod genera named in the 19th century, reflecting the early stages of dinosaur paleontology. Its complex taxonomic history, with many species being assigned and later re-evaluated, illustrates the challenges scientists face when working with incomplete fossil specimens. It highlights how scientific understanding of dinosaurs evolves as new discoveries are made and older material is restudied with modern techniques.

Ongoing research related to Bothriospondylus mainly involves re-assessing its validity and its relationship to other sauropods. Paleontologists continue to study Late Jurassic European sauropod faunas to better understand their diversity and evolutionary connections. While Bothriospondylus itself might remain a nomen dubium unless more complete and clearly identifiable fossils are discovered, the study of the fossils once attributed to it contributes to a broader understanding of sauropod anatomy and distribution during this period. The story of Bothriospondylus underscores the importance of well-preserved and diagnostic fossils for accurately naming and classifying extinct animals.