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Fossil Friday: Venetoraptor Is Not the Archaeopteryx of Pterosaurs

September 15, 2023, 6:54 AM
Image: Venetoraptor gassenae, modified from Müller et al. 2023 fig. 1, fair use.

In a recent Fossil Friday article for Evolution News (Bechly 2023), I discussed the abrupt origin of gliding and flying reptiles in the Triassic period. This includes the origin of pterosaurs, of which we find the earliest fossil record mainly from the Triassic of the Alps in central Europe (Barrett et al. 2008) such as the famous Eudimorphodon. The ages given by the notoriously unreliable Wikipedia for some of these Triassic pterosaurs as up to 228 million years are often false: The oldest undisputed fossil record of pterosaurs seem to be Austriadactylus, Carniadactylus, Preondactylus, and Seazzadactylus from the Dolomia di Forni Formation, which is dated to a late middle-late Norian (Alaunian 3-Sevatian) age (Wild 1984, Dalla Vecchia 1998, 2003, 2006, 2009, 2013, 2014, 2019) of about 209 million years (Lucas 2013). The somewhat controversial paleontologist Kellner (2015) described Bergamodactylus from the Calcari di Zorzino Formation, which is dated to an upper Alaunian age of about 210 million years (Dalla Vecchia 2009). The only exceptions from the Alpine distribution of Triassic pterosaurs are two new genera of raeticodactylid pterosaurs from the Triassic of Argentina (Martínez et al. 2022), as well as Arcticodactylus, which was also described by Kellner (2015) as a diminutive eudimorphodontid ptero­saur from the Ørsted Dal Member of the Fleming Fjord Formation in East Greenland.

This Greenland locality is estimated to be at least of middle Norian (Alaunian) age (Jenkins et al. 1994, 2001) of about 216-209 million years according to the most recent dating of the Alaunian (Lucas 2013). This could actually make the latter two taxa to the oldest known pterosaurs. Faxinalipterus, a presumed pterosaur from the early Norian of Brazil, was recently revealed to be a flightless lagerpetid reptile (Kellner et al. 2022, PeerJ 2022). However, there is even some more controversial evidence for the existence of derived pterosaurs in the previous Carnian period of North America about 237-221 million years ago (Andres 2006, Upchurch et al. 2014, Paul 2022). Of course, all these early pterosaurs were already perfectly adapted to powered flight and featured all the distinctive body plan characters of pterosaurs, especially large wings on the forelegs, which are supported by an enormously prolonged fourth finger.

Out of Thin Air?

So, where did these pterosaurs come from? It looks like they appear out of thin air. Paleobiologists searched for potential terrestrial precursors and often suspected the enigmatic small bipedal reptile Scleromochlus from the early Triassic of Scotland as a likely candidate.

For many decades there was considerable scientific controversy around the origin of pterosaurs (see Hone & Benton 2008, Da Silva et al. 2022), with mainly two rivalling schools of thought on the ancestry of pterosaurs: one more fringe school suggested that they were derived from the Triassic prolacertiforms (see Hone & Benton 2007 and Baron 2021 for a critical discussion), especially gliding forms like Sharovipteryx, which makes not much sense given the fact that those gliders had their hind legs modified as wings instead of the forelegs. Most other experts therefore rather agreed that pterosaurs are archosaurs and closely related to the dinosaur lineage (Baron 2021). Until recently it became the prevailing consensus view among the experts that the Triassic reptiles Scleromochlus and the similar Lagerpetidae were basal side branches of the lineage leading to dinosaurs and birds, which was backed by various extensive cladistic studies (e.g., Benton 1999, Hone & Benton 2007, 2008, Nesbitt 2011, Kammer et al. 2020). As late as three years ago Scleromochlus was recovered as basal Archosauriform (Bennett 2020), thus not more closely related to pterosaurs. These views and all previous phylogenetic trees were recently overturned by several newer studies, which indeed suggest that these taxa rather belong to the early stem group of pterosaurs (Ezcurra et al. 2020, Padian 2020, Baron 2021, Da Silva et al. 2022, Foffa et al. 2022, Kellner et al. 2022, Müller 2022). Now, a partial skeleton of a new lagerpetid taxon has been described from the Late Triassic (232-227 mya) of southern Brazil and named Venetoraptor gassenae (Müller et al. 2023). The analysis of this skeleton added further support for a pterosaur relationship of lagerpetids. That’s great, but how did flying pterosaurs with large winged forelegs originate from such bipedal terrestrial reptiles with smaller forelegs?

Two Proposed Models

A recent article summarized that “Two models have been proposed for pterosaurs early evolution: they originated at the beginning of the Triassic or even in the Permian (over 250 million years ago) and had a long evolutionary history without leaving any fossil record (the “Ice Berg” Model) or they originated close to their appearance in the fossil record and rapidly spread and differentiated (the “Big Bang” Model). “The close relationships with lagerpetids support the ‘Big Bang’ Model”, states the pterosaur specialist Fabio M. Dalla Vecchia.” (ICP 2020, Pivetta 2021).

Dalla Vecchia (2013) had reviewed the early fossil record of pterosaurs and found that “a ‘Big Bang’ model for their early history fits better with the fossil record: the earliest unequivocal pterosaurs show a sudden and geographically limited appearance in the fossil record, as well as a relatively high burst of diversity and considerable morphologic disparity.” Such an abrupt origin of pterosaurs, with the correlated very fast re-engineering of the body plan in terms of adaptation towards powered flight, or course also implies a significant waiting time problem (Bechly 2022), because the origin and fixation of the required genetic changes cannot be accomodated within the available window of time with an unguided evolutionary process. Thus, the fossil record of pterosaurs rather supports the predictions of intelligent design theorists.

Nevertheless, the fossil evidence also seems to lend at least some support for common descent of lagerpetids and pterosaurs, which is allegedly shown by successful predictions like the following: In a blog post, pterosaur expert David Hone (2013) characterized the predicted pterosaur ancestor as an arboreal animal with an archosauromorph-like anatomy close to that of Scleromochlus, fingers with large claws, an elongate fourth finger that is still shorter than that of pterosaurs, as well as an absent fifth finger. In all fairness this prediction indeed matches the anatomy of Venetoraptor well enough to be elegantly explained by common ancestry. It also roughly fits with the evolutionary scenario proposed by Bennett (2008: Fig. 6) for the evolution of pterosaur wings.

Two Significant Problems

However, there are still two significant problems with this apparently successful prediction:

  1. It is in a way circular, because it was already made based on the very assumption of a Scleromochlus-like and thus lagerpetid-like ancestor.
  2. More importantly, the slightly enlarged fourth finger of Venetoraptor cannot be considered as a homology with pterosaurs, because in the phylogenetic analysis Venetoraptor is resolved as nested within those lagerpetids with normal shorter fourth finger. The most parsimonious interpretation is therefore a convergence, contrary to the embarrassingly incoherent claim of Rodrigo Müller, the leading author of the Venetoraptor paper, that Venetoraptor “may represent the transition of lagerpetids towards pterosaurs” (Müller quoted in Wong 2023). The fact that a slightly enlarged fourth finger is also found in the basal dinosauromorph Saltopus (Benton & Walker 2011) makes a convergence even more likely. When the very scientists, who publish papers with grandiose claims about phylogenetics and evolution in prestigious journals like Nature, obviously are not even able to draw conclusions that are consistent with their own phylogenetic reconstructions and modern cladistic reasoning, how many more sloppy errors may hide in such studies of often very fragmentary fossil material (note: all Triassic pterosaurs are only known from fragmentary remains, and the oldest well-documented taxon of the early pterosaurs is the Lower Jurassic Dimorphodon, see Witton 2015)?

Moreover, Scleromochlus and lagerpetids like Venetoraptor lack any other typical adaptations of pterosaurs and show very different proportions of the arms and legs, as was explicitly admitted in the seminal study by Müller (2022), who found that “the postcranial skeleton of lagerpetids and pterosaurs are very different.” Consequently, we still lack any fossil intermediate form (missing link) documenting an evolutionary transition of walking terrestrial ancestors to actively flying pterosaurs with wings, in spite of highly misleading claims that “enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria” (Ezcurra et al. 2020). Apparently, one of the peer reviewers of the latter study did not really grasp this simple fact and triumphantly commented “Evolving powered flight is one of the biggest bugaboos that creationists lob at science. No transitional forms or features, they say. Well, here you are, honeys.”

Another peer reviewer was less enthusiastic and remarked, “I did not feel that the evidence was presented in as compelling and coherent a fashion as might have been.” Of course, Darwinists remain boldly optimistic that they will ultimately find something, as is evident by yet another peer reviewer comment, which said that we “await the discovery of a lagerpetid with long arms and other forelimb features that can help understand the origin of pterosaur flight” and “think these fossils will be found before too long, and some of the authors of this paper will probably be the people to find them. Good luck!” Well, after Venetoraptor clearly misses the mark, we surely wish them good luck, but honestly I don’t hold my breath given the total failure to find any transitional pterosaur ancestor in centuries of fervent search by vertebrate paleontologists around the globe.

Bennett (2020) admitted: “Although Scleromochlus is close to the Pterosauria in the cladogram, its crurotarsal ankle and terrestrial lifestyle suggest that it was not particularly close to the last non-volant ancestor origin of pterosaurs.” The same holds for Venetoraptor and other lagerpetids. This means that there is a large morphological gap and a very short window of time to close it. Not exactly what would have been predicted by Darwin, who quite likely would have been more willing than his modern successors to acknowledge that such conflicting evidence presents a formidable problem for his theory. In fact that’s exactly what he said in his Origin of Species about the fossil record. He still hoped that the gaps are just artefacts of our incomplete knowledge of the fossil record and therefore would be closed with future research. Even almost 165 years after Darwin with an exponential growth of knowledge about the fossil record this did not happen and the persisting gaps still bug Darwin’s successors until this day.

Hardly a Big Surprise

So, it is hardly a big surprise, that with the recent discovery of Venetoraptor, some media reports got carried away and their authors apparently did not bother to really read the actual article, when they incorrectly claimed that Venetoraptor was a pterosaur ancestor (e.g., Motzer 2023, Yazgin 2023) or did possess a feather-like fur (Wong 2023), which is neither mentioned in the scientific study (Müller et al. 2023) nor preserved in the fossil material of Venetoraptor or any other lagerpetid. This way the public is greatly misled and in consequence you find such nonsense repeated over and over again on social media, when self-proclaimed defenders of Darwinism think they can refute the arguments of us critics with “modern science says …”. Surely, some other news reports (e.g., Timmons 2023, Yirka 2023) more or less correctly represented what the scientist actually said, but which layman has the expertise to separate the wheat from the chaff?

The ubiquitous phenomenon of fake news is unfortunately not restricted to political and social issues but more and more becomes a problem in popular science communication. You can neither trust press releases and media reports nor science popularizers like Bill Nye or David Attenborough, who have far more of a worldview agenda than than they do scientific expertise. You cannot even trust the scientists themselves, who are often openly encouraged by PR departments to oversell their results to boost their careers and grants. Good science is going down the drain. This is a genuine and objective problem, which I observed and discussed with colleagues long before I became a Darwin critic and ID proponent.

Long story short: Forget all the pop science ballyhoo, and if you should not trust my word, just check the provided primary sources to see that there is much ado about nothing concerning the alleged recent breakthrough in our knowledge on the evolutionary origin of pterosaurs. It’s still a complete mystery and defies Darwinian expectations.

P.S.: I am grateful to an unnamed source for providing helpful comments and references for this article. The source prefers to stay anonymous for obvious reasons.

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