Description and Classification

Oceanotitan was a large, four-legged herbivore with a long neck and tail, typical of sauropod dinosaurs. Based on the discovered bones, scientists estimate it was about 13.5 meters (approximately 44 feet) long, although this individual might not have been fully grown. The known fossil material includes several tail vertebrae, chevrons (bones on the underside of the tail), a shoulder blade (scapula), a coracoid (another shoulder bone), parts of the sternum, pelvic bones (ilium, ischium, and pubis), and an almost complete hind limb (femur, tibia, fibula, and ankle bone).

Oceanotitan is classified as a sauropod dinosaur belonging to the group Titanosauriformes. More specifically, it is considered a basal (early-branching) member of Somphospondyli, a large and diverse clade of titanosauriforms that includes the later, giant titanosaurs like Argentinosaurus. Its position in the dinosaur family tree helps scientists understand the early evolution and spread of these giant plant-eaters, particularly in Europe before the Cretaceous period. It shows some similarities to other European sauropods from the Jurassic, such as Lusotitan, also from Portugal, and provides clues about their relationships.

Distinguishing Features

Oceanotitan can be identified by several unique characteristics found in its bones. These features help paleontologists distinguish it from other sauropods:

• The front tail vertebrae have a unique, fan-shaped bony ridge (lamina) that connects certain parts of the vertebra to the neural spine (the bony projection on top).
• The scapula (shoulder blade) has an unusually rounded and expanded upper edge.
• The ischium (a bone in the pelvis) has a particularly long connection point for the pubis (another pelvic bone).
• The femur (thigh bone) has a distinctively sloped shape at its upper-inner end where it connects to the hip.

Paleoenvironment and Diet

Oceanotitan lived in what is now Portugal during the Late Jurassic. The Lourinhã Formation, where its fossils were found, represents a coastal environment with river deltas and lagoons. This area was close to the shores of the young, opening North Atlantic Ocean. The climate was likely warm with seasonal rainfall, supporting a rich variety of plant life.

As a herbivore, Oceanotitan would have eaten plants available in its habitat. Its long neck would have allowed it to browse on vegetation at different heights, possibly feeding on conifers, cycads, ferns, and ginkgoes, which were common during the Jurassic period. It shared this dynamic ecosystem with a diverse range of other dinosaurs. These included large theropod predators like Torvosaurus gurneyi and Lourinhanosaurus, other sauropods such as Lusotitan and Dinheirosaurus, armored stegosaurs like Miragaia, and various ornithopod dinosaurs.

Significance and Ongoing Research

The discovery of Oceanotitan is significant because it adds to our knowledge of European sauropod diversity during the Late Jurassic. It provides valuable information about the early members of the Somphospondyli group and their presence in Laurasia (the ancient northern supercontinent that included Europe and North America). The fossils from the Iberian Peninsula, including those of Oceanotitan, highlight this region as an important center for dinosaur evolution during this time.

Ongoing research on Oceanotitan focuses on further studying its anatomy to understand its exact relationships with other sauropods, like Turiasaurus from Spain or even early titanosaurs from Gondwana. Paleontologists hope to find more fossil material to get a more complete picture of its size, appearance, and biology. Continued exploration of the Lourinhã Formation will also help to better understand the environment Oceanotitan inhabited and its interactions with other species in its ecosystem.