[DMG] Bakiribu situation update

[R. Pêgas]

Dear colleagues,

Thank you for your concern regarding Bakiribu and the ongoing discussion. Scientific disagreement is both normal and necessary in paleontology, and unusual specimens should indeed be subjected to careful scrutiny and alternative interpretations. Our team is currently preparing a formal response to Unwin et al. (2026), but this requires time, as additional analyses are still underway. We thank you for your patience.
 
However, the broader context of this situation unfortunately involves more than scientific disagreement alone. It also involves ethical issues, which are the sole focus of this present communication. In recent weeks, public allegations have circulated suggesting that the Bakiribu material was being kept “under lock and key”, that access to the specimen had been denied, or that researchers would only be able to examine it after the current loan period, in the second semester of 2026. These claims are concerning because they are inaccurate.

The specimen is divided into two halves (MCC-1271.1-V and MPSC 7312), housed in two Brazilian public institutions: the Museu Câmara Cascudo (MCC) and the Museu de Paleontologia Plácido Cidade Nuvens (MPPCN), respectively. Specimen MCC-1271.1-V has never been loaned and has remained fully accessible throughout the entire period. As attested by the museum’s director, access to this specimen has never been requested so far (attached Document 1).

Specimen MPSC 7312 is currently on loan at MZUSP for ongoing analyses related to our reply to Unwin et al. (2026). After MPPCN was contacted by Kellner requesting access to the material (the only researcher to date who has requested access to it), our team actively invited him to examine the specimen at MZUSP. Kellner requested a specific date, but it was not logistically possible to arrange the visit at that specific date. A new visit date was proposed by our team, and we also informed him that we could provide high-quality photographs and that he could freely access the MCC specimen. However, Kellner declined all of these alternatives and did not demonstrate willingness to adjust to the proposed arrangements. These circumstances are likewise documented by the museum’s director (attached Document 2).

Under these circumstances, it is difficult to understand why public statements continued to suggest that access had been denied when, in fact, (1) no request was ever made to examine the MCC specimen, and (2) opportunities to examine the MPPCN specimen at MZUSP were offered but declined.

I should also note that this broader situation has unfortunately included repeated public misgendering and deadnaming, despite prior knowledge of my correct name and gender identity. I understand that this issue is separate from the scientific debate itself, and suggestions that raising this issue somehow constitutes a “shield” against scientific criticism are deeply unfair and misrepresent what is actually being discussed. This issue is relevant to the professional and ethical context in which statements about me and my conduct (and of my colleagues also) have been made. Scientific disagreement cannot be used to justify conduct that compromises the dignity of researchers or creates a hostile professional environment.

The circumstances described above are thoroughly documented through email correspondence and institutional communications. In consequence, the Ciência Hoje editorial board decided to remove the piece, permanently discontinue the entire column, and grant us a right-of-response  (https://web.archive.org/web/20260513195001/https://cienciahoje.org.br/direito-de-resposta/).

We are fully committed to addressing the scientific questions surrounding Bakiribu through evidence, anatomical analysis, and formal scientific publication. At the same time, I believe it is equally important that scientific disagreements be conducted with honesty, transparency, institutional responsibility, and mutual respect.

Regardless of whether Bakiribu ultimately proves to be a pterosaur or a fish, professional integrity and ethical conduct should never become collateral damage of scientific debate.

Best regards,

Rubi V. Pêgas (she/her)

rvpega...@gmail.com
https://www.pterosaurology.com

Visiting Professor

Universidade Federal do ABC

[Jaime Headden]

I'm going to add on to this a little, in order to address one issue that was raised: the apparent issue or ethics of holotypes having part and counterpart in separate institutions.

The first described specimen of Sinosauropteryx prima is preserved in two separate institutions, namely the Geological Museum of China and the Nanjing Institute of Geology and Paleontology. Both part (GMV 2123) and counterpart (NGIP 127586) comprise the singular holotype. The process in which the two halves were sold by a private farmer was perfectly legal, and at the time, had happened already to a large number of fossil birds now in the collections of various institutions in NE China.

I object to the moral question being raised in response as if the splitting of a type across institutions is somehow problematic other than being tedious, for the sake of preserving information should one institution incur a threat to its collections. Cast can only do so much. Furthermore, it seems curious that some who commented on this fact (for the current specimen of note) did not consider also various fossil avians and pre-avian theropods, when they should have. I would leave the other matters to logical deduction, since I do not wish to stir a hornet's nest.

Cheers,

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Jaime A. Headden

The Bite Stuff: http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth" - P. B. Medawar (1969)

[Mickey Mortimer]

Besides Sinosauropteryx, other Mesozoic theropods with holotypes spread between institutions are- Xenotarsosaurus (initially), Neovenator, Shixinggia, Archaeopteryx (holotype feather) and Halimornis.

This isn't including cases like Imperobator, Variraptor, etc. where material discovered later was assigned to the type individual and placed in a different institution, or like Liaoxiornis/Lingyuanornis where parts of the type specimen were described as different taxa.

Mickey Mortimer

[Hebert Bruno Campos]

Hi there,

I would like to briefly emphasize a point that I consider essential in the current discussion about the interpretation of Bakiribu waridza and its broader paleontological context:

The Romualdo Formation is exceptionally rich in fossil fishes, both in abundance and diversity. Actinopterygians, coelacanths, pycnodontiforms, aspidorhynchids, amiiforms, and other fish groups are among the most characteristic and frequently preserved vertebrates in this unit (Maisey, 1991; Martill, 1993). Fish remains occur not only as articulated specimens, but also as isolated bones, disarticulated elements, scales, cranial fragments, branchial structures, and concentrated associations within calcareous concretions. In this context, any fragmentary, delicate, elongate, or filament-like skeletal material should first be evaluated against the wide range of fish anatomy known from the Romualdo Formation before being assigned to Pterosauria.

By contrast, there is currently no well-established record of a ctenochasmatid pterosaur from the Romualdo Formation. The pterosaur assemblage of this unit is diverse, but it is dominated by anhanguerians, tapejarids, thalassodromids, chaoyangopterids, dsungaripterids, and other ornithocheiriform or azhdarchoid lineages. A ctenochasmatid occurrence would therefore represent an extraordinary addition to the Romualdo fauna and should require especially strong anatomical evidence.

This is why the interpretation of Bakiribu as a ctenochasmatid pterosaur appears particularly fragile. It requires accepting not only that the material is pterosaurian, but also that it belongs to a clade otherwise unknown from the Romualdo Formation, and that the association represents a regurgitalite involving a highly specific paleobiological scenario. Given the abundance of fish remains in the same unit, a fish-based interpretation is, at minimum, a highly plausible and more conservative alternative that must be rigorously excluded before any extraordinary pterosaurian hypothesis can be accepted.

In my view, the central issue is not whether unusual pterosaurs could exist in the Romualdo Formation. Of course they could. The issue is whether the available anatomical and taphonomic evidence is strong enough to support such a claim. At present, the fish-rich context of the Romualdo Formation and the lack of independent evidence for ctenochasmatids in this assemblage make the pterosaur interpretation difficult to sustain without additional, detailed, and openly accessible comparative data.

Best regards,

Hebert

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[Jaime Headden]

No one discounts the right to refute. That's not the issue at hand. An argument was made and published regarding the identification of the material, while an editor discussed accessibility issues (which the authors didn't raise). I've kept my comments on the veracity of Rubi's claims private (for the most part) because I believe the best venue for this type of discussion is generally where it's been, where she's indicated it will be: in publications.

Cheers,

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[Hebert Bruno Campos]

Hi Jaime,

Thank you — I agree with your point!

The right to refute is not the problem. On the contrary, it is an essential part of the scientific process. The central issue is that two different matters are now being discussed simultaneously: first, the published anatomical argument concerning the identification of the material; and second, the editorial comments regarding access to the specimen and the conditions for independent reassessment.

I also agree that the strongest and most appropriate venue for resolving the anatomical question is the scientific literature. If Rubi and colleagues are preparing a formal response, that is precisely where the evidence should be presented: comparative anatomy, imaging, taphonomic interpretation, and a clear explanation of why the material should be regarded as pterosaurian rather than fish.

At the same time, I think the accessibility issue remains relevant, not as a substitute for the anatomical debate, but as part of the conditions that allow the debate to be tested. If a published reinterpretation challenges the identity of a name-bearing specimen, then transparency about access, repositories, images, loans, and examination conditions becomes scientifically important.

So I agree with your caution. Personal claims and counterclaims are not the best path forward. The decisive discussion should be evidence-based and published. My concern is only that, for such a disputed specimen, the process must remain as transparent, accessible, and reproducible as possible.

Best wishes,

Hebert

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[R. Pêgas]

Hebert, 

We have already clarified that a reply is in the works. Also, I have already provided transparent institutional documentation attesting that the editorial claims about accessibility issues are false, and that the material is accessible. 

Therefore, why do you keep spamming the DMG about concerns that have already been solved? Did you miss something in my email?

Best,

Rubi

Rubi V. Pêgas (she/her)

rvpega...@gmail.com
https://www.pterosaurology.com

Visiting Professor

Universidade Federal do ABC

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