We are very pleased to present the first contribution by an external author, Paul P. Stewens, doctoral researcher at Maastricht University and associated researcher at the UNESCO Chair in Cultural Heritage and Emerging Crime. His article explores the restitution of trafficked fossils, a subject which also falls within the broader field of art law, since objects of palaeontological interest form part of the legal definition of cultural property within the scope of the UNESCO 1970 Convention and, in many cases, hold cultural, scientific, economic, or spiritual value.
What do dinosaurs, AI, and warships have in common? We could certainly imagine a horrible but wildly entertaining B-movie that brings these things together, but the (arguably) more intriguing answer is that the governments of Brazil and Germany recently announced their collaboration in these and other areas. During a major industry fair in Hanover (Germany) in April 2026, the two states announced a Joint Declaration of Intent on Artificial Intelligence Partnership, a Letter of Intent concerning Industrial Cooperation related to the Tamandaré-Class Frigates Programme — and the decision to repatriate a dinosaur fossil from Stuttgart (Germany) to Brazil. After 35 years in Germany and three years of advocacy for repatriation, the fossil of Irritator challengeri is finally going home. The days of restitution debates focussing on artworks, antiquities, and ethnological collections alone are counted; fossil repatriation is becoming part of the conversation.
A Brazilian dinosaur in Germany
The fossil whose repatriation Brazil has been seeking is the holotype — a specimen upon which an entirely new species is described — of Irritator challengeri, a dinosaur of approximately six meters in length that fed on fish and other small animals some 110 million years ago in what is now Brazil.
The fossil was discovered during a commercial excavation and then artificially altered before being trafficked to Germany, where the State Museum of Natural History Stuttgart acquired it in 1991. Such modifications are not uncommon in the illicit fossil trade where specimens may be reconstructed, enhanced, or reshaped to appear more complete or spectacular and thereby command higher prices. A German-British team of palaeontologists then described the specimen as a new genus and species in 1996, naming it after “irritation, the feeling the authors felt (understated here) when discovering that the snout had been artificially elongated.”
In 2023, a study which re-assessed the specimen using digital methods put Irritator on the radar of Brazilian repatriation requests. Particularly the authors’ “Ethics Statement” sparked controversy since it seemed to claim that the export of the fossil from Brazil had at least not been unlawful and that it was the property of the State of Baden-Württemberg where the museum is located.
At that time, Brazil had already become a major advocate for the repatriation of fossils. As a country heavily affected by illicit trafficking, Brazil has made the recovery of its palaeontological heritage a political and diplomatic priority in response to bottom-up advocacy campaigns. In recent years, fossils have successfully been recovered from France, Germany, Switzerland, and the United States. The repatriation campaign #UbirajaraBelongstoBR had just resulted in the return of another fossil (“Ubirajara jubatus) housed by a nearby museum, providing a template for diplomatic negotiations and public advocacy under the #IrritatorBelongstoBR. It took three years of advocacy, an open letter with over 1,800 signatures, a petition with over 32,000 supporters, and protracted diplomatic negotiations for Germany and Brazil to finally agree: Irritator will go back.
Legal pathways to fossil restitution
I have explored the legal issues surrounding the Brazilian fossil repatriation claims in-depth in the International Journal of Cultural Property back in 2023; this is a concise summary with some additional observations.
To already dismiss the most evident pathway: the 1970 UNESCO Convention is inapplicable to the Brazilian claims. Importantly, this is a matter ratione temporis, not ratione materiae. Article 1 of the Convention, which defines its material scope, defines cultural property as including “(a) Rare collections and specimens of fauna, flora, minerals and anatomy, and objects of palaeontological interest”. This wording is unequivocal: fossils are cultural property under the Convention. However, Germany only ratified it on 30 November 2007 and thus after the import of the fossil in 1991. The non-retroactivity of the Convention thus precludes it applicability to the fossil of Irritator.
Private law happens to be the more interesting pathway. Brazil enacted a national ownership law regarding fossils in 1942, declaring that “the fossiliferous deposits are property of the Nation.” Many states, especially in Latin America, use this type of legal instrument to protect undiscovered antiquities from illicit excavation. By vesting the ownership of such items in the state, the government is able to act as a claimant in foreign civil courts to pursue a restitution claim under the respective private law instruments. Several countries have achieved the return of looted antiquities through such lawsuits, for example Iran (Iran v. Barakat Galleries) or Peru (LG München I, Az. 6 O 18699/06). Others were able to invoke their national ownership laws in criminal proceedings against individuals which resulted in the return of stolen artifacts; Guatemala (United States v. Hollinshead) and Mexico (United States v. McClain) are two notable examples.
Therefore, no reasons are evident as to why, on the merits, Brazil would not be able to rely on its national ownership law in a foreign court. In the case of Irritator, there is reason to believe that Brazil maintained ownership of the fossil: because Section 935 of the German Civil Code prevents the good faith acquisition (gutgläubiger Erwerb) of stolen or lost items, and because the museum might struggle to demonstrate the ten years of proprietary possession in good faith that Section 937 requires for acquisitive prescription (Ersitzung).
But what would, in any event, have prevented Brazil from having the restitution of Irritator ordered by a German court is the statute of limitations. Restitution claims under Section 985 German Civil Code lapse 30 years after they arise, which would have been, at the latest, upon the museum’s acquisition of the fossil in 1991. As a result, Brazil’s legal claim had already become time-barred by 2021, that is, two years before the launch of the repatriation campaign in 2023.
Is this a “return” or a “handover”?
The restitution of Irritator will be a voluntary one, agreed upon between the governments of Brazil and Germany. One matter, however, does not seem to have been resolved: what the transfer of the fossil should be called. In the English version of the Joint Declaration, the governments “welcome the willingness of the State of Baden-Württemberg […] to hand over the Irritator challengeri fossil to Brazil” (emphasis added). The German version uses a literal translation (“übergeben”).
The Portuguese version of the Joint Declaration on the website of the Brazilian Ministry of Foreign Affairs initially used that wording, too (“ceder o fóssil”). However, this formulation was promptly changed — perhaps in response to public backlash. Now, the Portuguese version reports an agreement to return (“retornar”) the fossil of Irritator.
This ex post facto deviation from the wording of the English version of the Joint Declaration is a curious footnote. It is without legal consequences as it relates to a political communiqué (as opposed to an international treaty) but highlights the importance of language in the context of restitution. “Handover” and “return” are two entirely different actions: you can hand over something to anybody — but you can only return it to its initial, rightful owner. The framing that the English and German versions use fails to acknowledge the reparative nature of the transfer of the fossil; it fails to explicate the reversal of its illicit trajectory.
Unlike the word “restitution,” the term “return” carries no immediate legal weight; it has no specialised legal meaning. Using it does not amount to an acknowledgement of wrongful conduct of the returning party; it would simply have acknowledged that this fossil will now be transferred to its rightful place. That even this small concession was too controversial to make its way into the Joint Declaration leaves a slight but bitter aftertaste to what is, in principle, a most welcome development.
The restitution of natural history specimens: an emerging field
The story of this dinosaur fossil could be that of a pre-Hispanic antiquity: discovered in an unlawful excavation, modified to increase its commercial value, trafficked across the Atlantic, studied in a European museum, voluntarily returned after public pressure and diplomatic negotiations. The same goes for the legal issues that come with this trajectory: the non-retroactivity of the 1970 UNESCO Convention; the possible invocation of a national ownership law to a claim that would have been subject to a statute of limitations; a disagreement whether this was a “return,” or a “handover.”
This is not a coincidence. Cultural artifacts and natural history specimens are two sides of the same restitution coin. They are (often) subject to the same legislation, they are affected by the same contexts of injustice and illicit trafficking, they face the same legal obstacles to restitution. Initiatives like those of Brazil blur, little by little, the sharp demarcation line between cultural museums and natural history museums. Every time a dinosaur goes back to Brazil, every time a Homo erectus returns to Indonesia, we move one step closer to an integrated restitution debate that pursues justice and equity across all areas of cultural property.