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Collector Mauricio Fernández Garza poses with a prized fossil specimen (left) and the cover of the Science issue in which a new shark species was described.

Raúl Palacios/Milenio

This ancient shark fossil is exquisite. But some researchers wonder if they’ll be able to study it

About 90 million years ago, an unusual shark cruised the shallow sea covering what is now Vallecillo, in the Mexican state of Nuevo León. After the animal died, conditions on the sea floor were just right to preserve its soft tissue and long, winglike fins. Described last month in Science, the shark, named Aquilolamna milarcae, made headlines around the world for its surprising similarities to today’s plankton-eating manta rays.

But for some paleontologists, the publication—by a team of mostly European scientists—also raises thorny questions about the role of private collections in their field and lingering scientific colonialism. The paper originally said the specimen was purchased by a collector, which is illegal under Mexican law. And a public museum founded by the collector, where the fossil was said to be accessible for study by other researchers, is not scheduled to open until later this year. That could mean other scientists “can’t know if what the [authors] described is true or not,” says Omar Regalado Fernández, an independent paleobiologist based in the United Kingdom who first raised concerns about the new paper on Twitter.

“A publication with Mexican material is always gratifying,” says Felisa Aguilar Arellano, a paleontologist at the National Institute of Anthropology and History (INAH), the federal agency that oversees paleontological research in Mexico. However, she says, “It is unethical to claim the existence of a museum” that is not yet finished, and “it is totally clear that [fossils], considered national heritage, are not marketable.”

Today, Science is publishing an Erratum noting that starting 1 May, the fossil will be housed in the Museo del Desierto in Saltillo, Mexico, until the originally listed public museum is built. For now, the fossil is at the home of Mauricio Fernández Garza, a Mexican businessman, politician, and fossil collector, who says the fossil is accessible to scientists.

Co-author Wolfgang Stinnesbeck, a paleontologist at Heidelberg University, says the team followed all Mexican laws and did not purchase the fossil, which he says is officially registered with INAH, as required.

Fernández Garza explains he did not purchase the fossil itself. The shark turned up in a slab of rock after he purchased it from a fossil-rich limestone quarry in Vallecillo, he says. “I buy the rocks” that might contain fossils, he says; this is legal under Mexican law. He and Stinnesbeck say buying the slabs saves potential fossils from destruction. (Fernández Garza adds that organized crime has recently taken an interest in the Vallecillo site and that other private collectors are now illegally buying its fossils.)

On 8 April, Science made an online correction to the paper’s Supplementary Materials, updating the fossil’s current location and removing the word “purchased” from the Materials and Methods section. “In order to avoid a mix-up and misinterpretation of these circumstances [around the fossil discovery] we removed the word ‘purchased,’ which—as we know now—caused unexpected problems,” Stinnesbeck wrote in an email.

Local preparator Margarito González González, the only Mexican co-author on the paper, cleaned and prepared the fossil. Fernández Garza then allowed Stinnesbeck and his team to study it in 2018. “We obeyed all legislations in Mexico,” Stinnesbeck says.

Aguilar Arellano felt that the original paper gave the false impression that buying fossils in Mexico is legal. “We know fossil trade exists, unfortunately,” she says. “But we’re trying to … mitigate these actions.”

For paleobiologist Nussaïbah Raja Schoob of the Friedrich Alexander University of Erlangen-Nuremberg, buying slabs from a quarry known for fossils “seems to be the exploitation of a legal loophole.” She adds: “As part of the review process, the journal should already be asking these questions about provenance.” Sacha Vignieri, a deputy editor at Science, wrote in an email that editors are proactive in asking authors to meet requirements pertaining to legality and ethical use for all paleontology papers.

INAH has other concerns, Aguilar Arellano says. The authors, she says, failed to comply with INAH’s protocol in describing a holotype—a specimen used to describe a new species. Holotypes are supposed to be stored in a scientific, public collection, she says, but the fossil is registered to Fernández Garza’s private collection. INAH’s Paleontological Council says it plans to write to Science with its concerns.

Stinnesbeck agrees that holotypes must be stored with public access and says the new arrangements fulfill that requirement. When the paper was submitted, he said, the fossil was destined for the new public La Milarca Museum, then scheduled to open at the end of 2020, in time for publication. That museum is meant to be a replica of Fernández Garza’s mansion and will house only a couple of fossils from his private collection, according to Fernández Garza. However, the pandemic delayed construction. While dealing with reviewers’ queries last year, the museum’s construction timetable “slipped our mind,” Stinnesbeck wrote in an email. “All of us were convinced that the opening of the museum would happen.”

Science’s editorial policy requires all fossils described in the journal to be accessible to researchers, but allows fossils to be deposited in private collections as long as “full public access is available.” But some paleontologists are not pleased that the fossil is now in a collector’s home and will reside in a nonacademic institution in the coming months. In a private collection, “access will always remain at the discretion of the collector,” says Raja Schoob. The Society of Vertebrate Paleontology, in its Code of Ethics, stresses public access to published fossils and has called on journal editors not to publish on privately held specimens.

Some journals do require fossils to be in public collections, says Alexander Kellner, a paleontologist and director of the National Museum at the Federal University of Rio de Janeiro. He says that’s the case for the Annals of the Brazilian Academy of Sciences, of which he is editor-in-chief. (Kellner previously charged that Eberhard Frey, a paleontologist at the State Museum of Natural History Karlsruhe and a co-author on the shark paper, illegally took a maned dinosaur fossil out of Brazil. Frey denies the claim.)

The controversy over A. milarcae comes at a moment when some paleontologists are pushing to eliminate the remnants of colonial practices, an issue that inflames the debate over the paper.

In Mexico, before a 1986 law made buying and selling fossils illegal, foreigners “came, they worked, they took things away, and you never heard about it,” says paleontologist Gerardo Carbot Chanona at the Eliseo Palacios Aguilera Museum of Paleontology in Tuxtla Gutiérrez, Mexico. He wishes Stinnesbeck’s team had collaborated with scientists based in Mexico—as new INAH guidelines, published on 4 February, require foreign researchers to do. He says such partnership is key to following Mexican laws, making sure fossils are collected and housed safely and publicly, and developing Mexico’s emerging paleontological community.

Collaborating with Mexican paleontologists in that way might have avoided the issues that arose in this paper, Raja Schoob says.

Frey counters that as long as all local laws are followed, doing research without local scientists “is not problematic.” He lamented that “everybody is seeking … juristic arguments to get fossils ‘nationalized’” rather than making international agreements to study them.

In Mexico, paleontologists say the paper has served as a wake-up call. “It is time” to review ethical codes again, Aguilar Arellano says. The new INAH guidelines requiring scientific collaboration will help avoid new controversies, Carbot Chanona says. “We are not closing the door to foreigners, but we do want them to be regulated in some way.”