The Early Jurassic

Early Jurassic

The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...

 sauropod dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s Zizhongosaurus

Zizhongosaurus

Zizhongosaurus is a genus of basal herbivorous sauropod dinosaur which lived in the Early Jurassic Period of China. It was a large-bodied herbivore characterized by a long neck....

, Barapasaurus

Barapasaurus

Barapasaurus is a genus of sauropod dinosaur from Early Jurassic rocks of India. The specific name for its only species, B. tagorei, means 'Tagore's', which honors Bengali poet, writer, painter, and musician Rabindranath Tagore.-Description:...

, Tazoudasaurus

Tazoudasaurus

Tazoudasaurus is a genus of vulcanodontid sauropod dinosaur hailing from the Early Jurassic Toundoute overthrust beds located in the High Moroccan Atlas Mountains. The remains, consisting of a partial adult skeleton and associated partial juvenile skeleton found in continental detrital sediments,...

, and Vulcanodon

Vulcanodon

Vulcanodon was a relatively small early sauropod dinosaur genus from the Early Jurassic of southern Africa. About 6.5 metres long, Vulcanodon was herbivorous and had unusually long bones of the first toe and large claws on the inside toes. The type species, V. karibaensis, was formally...

may form a natural group of basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by M.R. Cooper in 1984. In 1995 Hunt et al. published the opinion that the family is synonymous with the Barapasauridae. One of the key morphological features specific to the family is an unusually narrow sacrum

Sacrum

In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...

.