We invoke their name as an insult, but continuing discoveries about the extinct Neanderthal culture suggest the existence of a rich, complex symbolism we still do not fully understand. Now, we have another artefact to admire.

New archaeological research in Spain has uncovered the most modern evidence yet of a form of primitive jewellery from almost 40,000 years ago: an eagle talon carved by hand into the shape of a pendant to decorate what may have been "the last necklace made by the Neanderthals".

" Neanderthals used eagle talons as symbolic elements, probably as necklace pendants, from the beginnings of the mid Palaeolithic," explains archaeologist Antonio Rodríguez-Hidalgo from the Institute of Evolution in Africa (IDEA).

While Neanderthals have long been characterised as a highly primitive species of archaic human, new research is continually telling us unknown things about them – and not just about their bodies, bones, and bedtime companions, but also stuff like the art they made.

012 neanderthal talon 1(Antonio Rodríguez-Hidalgo)

In a new study, Rodríguez-Hidalgo and his team explored a cave called Cova Foradada: an archaeological site along the Mediterranean coast of northeast Spain.

Inside the cave the researchers found bone remains from the left foot of a Spanish imperial eagle (Aquila adalberti), bearing numerous marks that the researchers say are inconsistent with animal consumption.

Instead, they think the carved raptor phalange was cut to be a pendant, which might have been worn as a kind of symbolic necklace.

More than 20 finds like this have been made before (with similar sort of interpretations), spanning approximately 42,000 to 130,000 years ago. Indeed, the researchers say eagle talons are the oldest ornamental materials known in Europe.

But what sets the Cova Foradada talon apart is that, at about 39,000 years old, this is the most recent such Neanderthal eagle ornament we've ever discovered – occurring in history at the same time Neanderthals were becoming extinct – and the first-ever found on the Iberian Peninsula.

"This exceptional find reinforces their interpretation as symbolic elements, supporting and further suggesting that Neanderthals transmitted similar symbolic connotations to large raptors as current traditional societies," the authors write in their paper.

"The symbolic meaning of majestic eagles as large predators could thus be transmitted to some parts of their bodies as talons and feathers."

The talons are an example of what is known as Châtelperronian culture – a debated body of archaeological discoveries of shaped tools and blades occurring about 44,500 to 36,000 years ago.

While we can't definitively say what these carved raptor talons signified to Neanderthals so long ago, the researchers say it's possible different birds of prey (such as vulture and eagle species) meant different things to different Neanderthal populations, but might have been capable of interpretation across groups.

"Talons of different birds with different appearances and behaviours could transmit different messages about the identity of the bearer," the researchers explain.

"Our research suggests the presence of a common cultural territory in which the meaning conveyed by these large-raptor talons could probably be recognised by individuals from different groups."

Given how rare and ancient these cultural relics are, we can't say with much certainty what these claws meant to those who might have worn them long ago.

But with each new find, we discover what looks to be a framework of communication and expressing identity that we as modern humans can readily relate to.

"We're looking at evidence of traditions that have to do with social identification," anthropologist John Hawks from the University of Wisconsin-Madison, who wasn't involved with the study, told Smithsonian.

"Why do you wear ornaments? Why do you go through this trouble? Because you notice something interesting, you want to associate yourself with it, [and] you want it to mark yourself for other people to recognise."

The findings are reported in Science Advances.