Brontosaurus

MEANING: Thunder lizard

PERIOD: Late Jurassic

CONTINENT: North America

Brontosaurus was long considered a synonym of the closely related Apatosaurus, until a 2015 analysis concluded that it was a separate genus, worthy of its own name. Brontosaurus grew up to 22 m in length, and weighed around 17 t. Its head was small relative to its body, with a squared off snout lined with chisel-like teeth, well adapted for its herbivorous diet.

Brontosaurus is from the Late Jurassic. The Late Jurassic was a dynamic period, spanning from about 162 to 143 million years ago. The continents were continuing to drift apart, and the supercontinent Pangaea had fully split into Laurasia in the north and Gondwana in the south. This continental rearrangement led to the formation of large inland seas and shallow coastlines that fostered diverse ecosystems. The climate during the Late Jurassic was warm and humid, with lush forests of conifers and ferns that stretched across much of the continents, creating a rich ecosystem where dinosaurs flourished the dominant land animals.

Dinosaurs continued to diversify through the Late Jurassic, with some of the most famous species evolving in this time. Many well-known sauropods, such as Brachiosaurus and Apatosaurus roamed the land, exhibiting niche partitioning with their selectively distinct neck positions. Alongside them, stegosaurs became widespread, their plates and spikes making them one of the era's most recognizable groups. Theropods like Allosaurus and Ceratosaurus were the apex predators, evolving large, powerful bodies and sharp teeth that allowed them to hunt the gigantic herbivores. The early evolution of birds was taking place, setting the stage for the numerous species that would fill the skies in the eras to come.

Unlike the dramatic mass extinctions that marked the beginning and end of the Mesozoic, the Jurassic Period ended without a sharp boundary. As the continents continued to drift, ecosystems gradually transformed into unique habitats that supported the more specialized dinosaur species of the Cretaceous.

Brontosaurus is a diplodocid. Diplodocidae is a family of long-necked sauropod dinosaurs that includes some of the longest animals to have ever walked the Earth. These herbivorous giants lived during the Late Jurassic Period and are known for their exceptionally elongated bodies, particularly their necks and tails. Diplodocids typically had relatively light, whip-like tails and long, slender necks with peg-like teeth concentrated at the front of the jaws - adaptations likely suited for stripping leaves from soft vegetation.

Unlike some other sauropod groups, diplodocids had relatively low-slung bodies and held their necks horizontally, possibly allowing them to feed efficiently on low-lying plants. Fossil evidence suggests they were abundant in what is now North America, South America, and parts of Africa and Europe, indicating a wide distribution. Their streamlined body plan and specialized feeding strategies made them one of the most successful sauropod lineages of the Jurassic, before eventually disappearing by the beginning of the Cretaceous.