Gandititan

MEANING: Ganzhou geology giant

PERIOD: Late Cretaceous

CONTINENT: Asia

Gandititan is a basal titanosaurian sauropod dinosaur from the Late Cretaceous of what is now China. Titanosauria have a wide range of body sizes, and Gandititan falls around the middle, slightly on the smaller side. Discovered with a fairly well articluated spine from neck to tail, Gandititan is estimated at about 14 m in total body length.

Abstract from paper: Large quadrupedal sauropod dinosaurs of the group Titanosauria were globally distributed in the Late Cretaceous. Many titanosaurian species have been discovered in eastern Asia, but most of them are controversial and represented by poorly preserved remains. Here, we describe a new titanosaur, Gandititan cavocaudatus gen. et sp. nov., based on a partial skeleton recovered from the lower Upper Cretaceous of Ganxian County, Ganzhou City, southern China, and comprising six articulated cervical vertebrae, two partial dorsal vertebrae, and a complete sacrum preserved in articulation with the first 17 caudal vertebrae and part of the right pelvis. Gandititan can be diagnosed on the basis of the following autapomorphies: long and narrow fossae present on the dorsal and ventral parts of the lateral surfaces of the cervical centra, sacral neural spines forming a dorsal platform with wave-shaped lateral margins, anteriormost six caudal vertebrae with bifurcated neural spines, the presence of prominent triangular flanges on the transverse processes of the anteriormost caudal vertebrae, a pair of slit-like foramina present on the ventral surface of each anterior caudal centrum, lateral surfaces of neural arches strongly excavated, additional spinoprezygapophyseal laminae present, and a prominent lamina extending horizontally between the bases of the pre- and postzygapophyses in some anterior caudal vertebrae. An expanded phylogenetic analysis places Gandititan as the sister taxon to Abdarainurus, within a clade of non-lithostrotian titanosaurs that also includes the Chinese titanosaurs Dongyangosaurus, Baotianmansaurus and Huabeisaurus, as well as the Argentine titanosaur Andesaurus. Such results imply the possible existence of a previously unrecognized group of titanosaurs in eastern Asia, and potential dispersal of titanosaurs between Asia and South America during the mid-Cretaceous.

Gandititan is from the Late Cretaceous. The Cretaceous is the third and final geological period of the Mesozoic Era, with the Late Cretaceous making up roughly the second half of it, lasting from about 100 to 66 million years ago. It was a time of significant evolutionary change, with dinosaurs reaching their greatest diversity before the mass extinction at the end of the Cretaceous.

The Cretaceous was a period with a relatively warm climate, though the Late Cretaceous experienced a global cooling trend, caused by falling levels of carbon dioxide in the atmosphere. The continents were nearing their present positions, but high sea levels flooded low-lying regions, turning Europe into an archipelago, and forming the Western Interior Seaway in North America. These seas were home to a variety of marine reptiles, including mosasaurs and plesiosaurs, while pterosaurs and birds shared the skies.

On land, dinosaurs continued to thrive and diversify during the Late Cretaceous, producing many of the most well-known goups, including tyrannosaurs, hadrosaurs, and pachycephalosaurs. Established Cretaceous dinosaur clades like the ceratopsians, ankylosaurs, and dromaeosaurs continued to flourish. Sauropod species consisted almost exclusively of titanosaurs, which seemed to be confined to the Southern Hemisphere for much of the Late Cretaceous. Flowering plants and grasses diversified and spread, becoming the dominant flora similar to what we see today.

The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene (K–Pg) extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs, and large marine reptiles, died out. This event, likely triggered by an asteroid impact, is marked by the abrupt K–Pg boundary, a distinct geologic layer separating the Mesozoic and Cenozoic Eras. In its aftermath, mammals and avian dinosaurs rapidly diversified, becoming the dominant land animals of the Cenozoic Era.

Gandititan is a titanosaur. Titanosauria was a diverse and widespread group of sauropod dinosaurs that lived during the Cretaceous Period, especially flourishing in the Late Cretaceous. As the final major lineage of sauropods, they replaced older groups like the diplodocids and brachiosaurids. Sauropods are herbivorous saurischian dinosaurs known for their long necks and immense size, and titanosaurs took this to the greatest extreme. Estimates vary, but the largest titanosaurs are estimated at upward of around 40 m long, and weighing 100 t in total body mass, or possibly even more. While this derived group included the largest animals ever to walk the earth, it is also notable for its diversity - titanosauria also includes some of the smallest sauropods.

Titanosaurs had a remarkable global distribution during the Cretaceous, with fossil remains discovered on nearly every continent, adapting to a wide range of environments. They were especially diverse and abundant in the Southern Hemisphere, where most of the larger species have been found. In contrast, titanosaurs are notably rare in North America, where they appear to have largely disappeared for much of the Late Cretaceous. This uneven distribution may reflect changing environmental conditions, or competition with other herbivores.