The dig recently yielded this pelvic bone from a creature related to diplodocus (Image: Luis Alcala)

The new remains from Riodeva include a fossil pelvic bone of a large sauropod dinosaur that was related to the group Diplodocus.

A new park recently opened near the dig site to show off the bones to the public.

The new cache of fossils includes the bones of stegosaurs, famous for the plates that lined their backs.

We've still only excavated a small part of the site. Myself and my colleagues think we've got several years of work here at the site Luis Alcala, Palaeontological Foundation of Teruel

Luis Alcala, director of the Palaeontological Foundation of Teruel, told BBC News Online: "It's too early to say which dinosaurs they pertain to, but we have found the remains of various different dinosaurs, including large ones," he explained.

"There are some remains of sauropods, stegosaurs and also of carnivorous dinosaurs."

The new cache also contained the remains of crocodilians, Dr Alcala added. He said there were already suggestions the new remains could yield some surprises, but would not yet be drawn on this.

The pelvic bone may have belonged to a creature that looked much like this

"It's not as if I don't want to talk about it," he explained with a chuckle, "but we're still in the preliminary stages of our investigation."

The pelvic bone - a right ilion - belongs to a diplodocid, the family of dinosaurs which includes the famous sauropod Diplodocus.

Dr Alcala presented the Cretaceous-Period fossil at the 6th Geological Congress of Spain in Zaragoza last week.

In 2003, palaeontologists Alberto Cobos and Rafael Royo discovered bones at Riodeva that would later be shown to belong to a 35m-long (about 115ft) sauropod weighting 50 metric tonnes.

The huge sauropod was the largest dinosaur yet found in Europe. But the researchers have not yet classified it taxonomically.

It could belong to a new species, or could be related to a group that is already recognised such as Argentinasaurus.

"We've still only excavated a small part of the site," Dr Alcala told BBC News Online. "Myself and my colleagues think we've got several years of work here at the site.

"That's not to say we'll take several years to catalogue the dinosaurs that lived here. But there are some significant specimens that we'd prefer to excavate in the most precise way possible."