An artist's illustration showing Silutitan sinensis (left) and Hamititan xinjiangensis (right), with other theropods and dinosaur species in the surroundings.
CNN  — 

Scientists have confirmed the discovery of two massive new dinosaur species in northwest China – some of the first vertebrates uncovered in the region, according to a new study published Thursday.

A number of fossils have emerged from China’s northwest region in recent years, including Xinjiang and the Turpan-Hami Basin. The fossils include a number of pterosaurs (flying reptiles), preserved eggs and embryos – as well as fossil fragments of spinal vertebrae and rib cages, which scientists initially identified as belonging to three mystery dinosaurs.

The researchers have since determined that two of those specimens were from previously unknown species, which they have named Silutitan sinensis – “silu” meaning “Silk Road” in Mandarin – and Hamititan xinjiangensis, a nod to the region where it was found. Both incorporate the Greek word “titan,” which means “giant,” in reference to their size.

The Silutitan specimen is estimated to be over 20 meters (65.6 feet) long, while the Hamititan specimen was 17 meters (55.77 feet) long. That makes the dinosaurs almost as large as blue whales, which range from 23 to 30 meters (75 to 98 feet), depending on the hemisphere they’re located in.

The researchers, from the Chinese Academy of Sciences and the National Museum of Brazil, published their findings in Scientific Reports, part of the Nature family of journals.

Hamititan xinjiangensis (left) and Silutitan sinensis (right), depicted in an artist's illustration.

The fossil fragments were dated to the early Cretaceous period, about 120 to 130 million years ago. Both new species both belong to the sauropod family, a group of plant-eating dinosaurs known for their signature long necks, and that were the largest animals to ever walk the earth.

Apart from one pterosaur species and a theropod tooth, these two dinosaurs are also the first vertebrates reported in this region, “increasing the diversity of the fauna as well as the information on Chinese sauropods,” said the study.

The third specimen that researchers studied was not a new species, but may have been a somphospondylan sauropod, a group of dinosaurs that lived from the late Jurassic to late Cretaceous periods.

Researchers have made a number of discoveries in China over the past few decades, shedding more light on the diversity of sauropods in East Asia, said the study – though there is still debate over the relationships between species and their taxonomical classification, and where they fall in the dinosaur family tree.

China is experiencing a golden age of paleontology, with exciting fossil discoveries scattered across the country; a dinosaur was found preserved while sitting on a nest of eggs with fossilized embryos in southeast China earlier this year, while another new species was discovered in northeast China last September.