Stasis, misdirection and taxon exclusion in recent pterosaur studies

Several academic papers in the last few decades have reported that: 
1. All pterosaurs were quadrupeds based on the trackways and morphologies of a few.

2. All pterosaurs used a catapult tendon in the wing-finger to become airborne from a quadrupedal push-up configuration, thus with wings folded and ventrally oriented during take-off, unlike birds.

3. Azhdarchid pterosaurs with relatively reduced wings and very long necks tipped with large skulls were able to soar in the same manner as distinctly different sea pterosaurs and sea birds.

4. All pterosaurs had a deep chord wing membrane stretched between the wingtip and ankle. 

5. Anurognathid pterosaurs had owl-like scleral rings = eyeballs in the front half of the skull. 

6. Pterosaurs were basal archosaurs close to dinosaurs and crocodylomorphs, which matured allometrically (= with change). Therefore, Late Jurassic hummingbird-size pterosaurs must have been hatchlings to juveniles of coeval larger and morphologically different adult specimens. So hummingbird-size late Jurassic pterosaurs should not be included in phylogenetic analyses.

7. Traditional pterosaur outgroup taxa include bipedal Scleromochlus and bipedal dinosaurs. Recently bipedal Lagerpeton and kin were added to that list. But all pterosaurs were quadrupeds (see #1 above) not bipeds, like these putative ancestors. So other workers posit quadrupedal Euparkeria, Proterochampsa, Proterosuchus and Erythrosuchus as nearest known relatives.

8)  All derived pterosaurs belong to the traditional clade ‘Pterodactyloidea.’ 

Each of these textbook myths are considered below, then dismantled with evidence.

Sacral incorporation and ilium extension resulted from bipedal locomotion in both pre-birds and pre-pterosaurs for the same reason: Bipedal locomotion, a necessary precursor to flapping (bats are inverted bipeds) suspends the entire pre-pelvis mass over the toes, leveraged over the fulcrum of the acetabulum. Thus the toes have to be below the center of balance in bipeds – which have to be below the wing root in aerodynamically balanced flying vertebrates. Sacral incorporation and ilium extension is how the body responded to the strain by reinforcing that fulcrum over the acetabulum.

As an aside, in synapsids a third sacral is incorporated in Haptodus. A fourth is incorporated in Thrinaxodon. Notharctus had three sacrals. Humans have five fused sacrals. Elephants have four. Kangaroos have two. Cosesaurus had four unfused sacrals. Sharovipteryx had seven. Bergamodactylus had eight. Pteranodon had ten, several of which were fused. The London specimen of Archaeopteryx had seven. Tyrannosaurus had five.

As everyone knows, all birds and their theropod ancestors produced only bipedal (pes only) tracks. By contrast, many pterosaur tracks are quadrupedal with three fingers (1–3) oriented laterally to posteriorly.  Different from all other tetrapods, the posteriorly-oriented manual digit 3 indicates a secondarily acquired manual contact with the substrate. It produced no anterior force vector during the step cycle, distinct from all other quadrupeds.

Figure 1. Crayssac tracks matched to a walking trackmaker. ” data-image-caption=”

Figure 1. Crayssac tracks matched to a walking trackmaker.

” data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif?w=584″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif?w=584″ alt=”Figure 1. Crayssac tracks matched to a walking trackmaker. ” class=”wp-image-61360″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif?w=584 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif?w=150 150w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif?w=300 300w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/10/pterodacwalk60.gif 609w” sizes=”(max-width: 584px) 100vw, 584px” />

Matching quadrupedal pterosaur track-makers to Crayssac trackways indicates the forelimbs were used more like humans use ski poles, for stability in the (at least) three clades of pterosaurs in the large pterosaur tree (LPT, 268 taxa) that were beachcombing waders. That enables and requires an upright stance for the toes to remain beneath the shoulder girdles to match tracks, as in humans and birds.

See: https://reptileevolution.com/MPUM6009-3.htm.

See: https://pterosaurheresies.wordpress.com/2011/08/09/pterosaurs-bipedal-quadrupedal-or-both/

The typically omitted hypothesis of a pterosaur Cosesaurus/Rotodactylus ancestry (Peters 2000a,b, 2002, 2007) shows exactly when pterosaur ancestors experimented with and transitioned to bipedal locomotion. Like pterosaurs, Cosesaurus also had a locked-down elongated coracoid and strap-like scapula plus a broad sternal complex for flapping prior to flying. So did bipedal Sharovipteryx. So did bipedal Longisquama. So did bipedal Bergamodactylus (MPUM 6009).

See: https://www.researchgate.net/publication/328388115_Cosesaurus_aviceps_Sharovipteryx_mirabilis_and_Longisquama_insignis_Reinterpreted 

As an aside, crocodilians also have an elongate coracoid (aka a ‘stem-shaped bone’), but it is not locked-down. The coracoid still slides along the narrow interclavicle (Baier et al 2018), contributing to shoulder girdle mobility in Alligator.  This elongation was not present in the facultatively bipedal crocodile ancestors Terrestrisuchus and Litargosuchus, but was present in the secondarily quadrupedal Sphenosuchus and Hesperosuchus, Orthosuchus, Baurusuchus, Caiman and other extant crocs. In Alligator the coracoid remains low in lateral view, but broad in ventral view due to articulation with the narrow interclavicle. 

Distinct from small-clawed, plantigrade, Late Jurassic beach-combing and wading pterosaurs, Early Mesozoic pterosaurs had large manual claws ideal for clinging to tree trunks – not appropriate for quadrupedal excursions. In addition, overall proportions made Triassic and Early Jurassic pterosaurs awkward when forced into a quadrupedal crouch. Individual digitigrade pedal-only impressions match early pterosaurs (Peters 2000a). We also have bipedal, sometimes quadrupedal and always digitigrade Rotodactylus trackways matched to the manus and pes of Cosesaurus, the transitional taxon in this hypothesis of interrelationships and configurations. 

As an aside, Clark et al 1998 declared that all pterosaur foot posture was plantigrade due to the butt joint between the metatarsals and proximal phalanges in ‘Dimorphodon’ weintraubi. In counterpoint, pre-pterosaur (Rotodactylus) and basal pterosaur footprints indicate that butt joint served to elevate the proximal phalanges along with the metatarsus for a higher digitigrade foot posture (Peters 2000a). Whether a pterosaur foot was digitigrade or plantigrade can be determined from parallel interphalangeal line (PILs) analysis (Peters 2000a, 2010, 2011).

As balanced bipeds, pterosaurs (and their transitional ancestors) could stand erect, open their wings, flap to impress mates and also flap to take off with maximum thrust applied at takeoff with a little boost from the leaping hind limbs, just like volant Solnhofen birds. This hypothesis for the origin of flapping flight (Peters 2000a, b, 2002) finds an analog in the theropod-to-bird transition hypothesis, also supported by fossils and ichnites.

The quad launch catapult hypothesis: Academic pterosaur workers ignored bipedal pterosaur tracks and bipedal trackmaker ancestors (Peters 2000a). Instead they proposed that pterosaurs distributed weight equally between fore and hind limbs, like a giraffe. 

Given these parameters, a PhD new to flying reptiles (Habib 2008) proposed that all pterosaurs planted their wing fingers on the ground, then an elastic tendon catapulted the pterosaur into the air like a grasshopper. In this scenario the ventrally oriented and folded wings at takeoff would have a brief moment to rise, unfold, extend dorsally, then flap once in mid-air in time to avert a crash. Academics workers embraced the Habib quad-launch catapult hypothesis despite the danger and flaws.

Four other critical issues were ignored: 

1. The wing finger never impresses in pterosaur ichnites = tracks. So there can be no elastic snap catapult that involves the wing finger. 

2. Habib also cheated pterosaur anatomy by placing the free fingers above the implanted wing finger, ignoring the fact that only fingers 1–3 impressed in pterosaur ichnites. 

3. No transitional taxa were proposed to demonstrate how this dangerous practice might evolve. 

4. Proposed ancestors acceptable to academics were restricted to the biped Scleromochlus, which had the tiniest hands and fingers of all bipedal vertebrates.  Lagerpeton, another academically preferred outgroup taxon, was also a biped. Academics overlooked this configuration mismatch. 

Padian 1983 supported the erect, bipedal configuration hypothesis, which posits a bird-like pose in which the wings can be elevated at any time because the toes were on the ground at rest beneath the aerodynamic and terrestrial center of balance at the shoulder glenoid.

On the other hand, in 2016 Bristol University proposed the following project to incoming paleo students: “The main objective of this proposal is to investigate the effectiveness of the quadrupedal launch [of pterosaurs] and by comparing it with the bipedal launch of birds, test if it was one of the factors that enabled pterosaurs to become much larger than any bird, extant or extinct.” 

Note: Bristol U did not intend to test the hypothetical quad launch of pteros against the hypothetical bipedal launch of pteros. The latter option was not to be considered. 

See: https://pterosaurheresies.wordpress.com/2016/10/14/heres-a-pterosaur-proposal-doomed-to-a-crashlanding/

See: https://pterosaurheresies.wordpress.com/2016/10/14/heres-a-pterosaur-proposal-doomed-to-a-crashlanding/

3. The soaring giant pterosaur hypothesis 
All of the largest soaring sea birds and sea pterosaurs had enormous wings relative to skull + torso. However, these taxa were dwarfed in size and weight by the largest flightless birds, which had vestigial wings. These largest birds evolved from smaller relatives that gradually gave up flying – and only then were they able to become heavy-weight giants. This everyone agrees on. 

However, when it comes to pterosaurs, academics ignore the giant bird analog, aerodynamic limits and pterosaur anatomy. Distinct from sea pterosaurs, the largest azhdarchid pterosaurs had relatively small gracile wings. Giant azhdarchids evolved from smaller azhdarchids with vestigial distal wing phalanges. So these smaller taxa had already lost the ability to fly, but kept the ability to flap, as in penguins, emus and ostriches. Academics do not acknowledge the physics at play (weight increases with the cube of the height or length) when everything gets larger except the wings. Pterosaur experts report that giant pterosaurs could fly (Witton 2008, Witton and Naish 2008, Witton and Habib 2010) with membranes extending to the ankles (see #4 below). Museums hang giant pterosaur models and skeletons from ceiling wires with wings outstretched as if in flight following their impossible hypotheses. The flying model Quetzalcoatlus cheated azhdarchid anatomy when inventor Paul MacCready gave it extra-large wings and a shorter than real neck. 

See: https://pterosaurheresies.wordpress.com/2025/06/28/howtown-youtube-video-on-quetzalcoatlus/  

See: https://pterosaurheresies.wordpress.com/2018/06/02/why-we-think-giant-pterosaurs-could-fly-not/

A small flightless pterosaur (SoS 2428) was described here: https://www.researchgate.net/publication/328388664_First_Flightless_Pterosaur . Though not a sister to the azhdarchids it is in the same wading lineage and has similar proportions.https://pterosaurheresies.wordpress.com/2025/06/28/howtown-youtube-video-on-quetzalcoatlus/  

4. The deep chord (bat) wing membrane hypothesis
Since the discovery of pterosaurs, the traditional ‘look’ of the wing membrane has been bat-like = stretched between the wing tip and ankle. Such a membrane has never been found in fossils that preserve soft tissue. Rather all soft-tissue specimens demonstrate a narrow-chord wing membrane, like that of an albatross or sailplane, stretched between the wingtip and the elbow with an additional fuselage fillet between the elbow and mid-thigh (Peters 2002). 

In counterpoint, when describing the best narrow-chord membrane examples, like the Zittel wing of Rhamphorhynchus (BSPG 1880 II 8) and the Vienna specimen of Pterodactylus (NHMW 1975/1756))Elgin, Hone and Frey (2011) explained those away as ‘shrinkage’ because the authors favored, but never found examples of the deep chord, membrane-to-the-ankle. Sometimes wishful thinking, rather than data-driven science, gets past and passed by academic editors and referees.

Peters (1995, 2002) reported that Sordes had a shallow-chord wing membrane that could fold completely away, as in bats and birds. Earlier the PIN 2585 specimen of Sordes was described by insect-specialist Sharov (1971), then Unwin (1995) and Unwin and Bakhurina (1994) without additional detail, a deep chord membrane on the taphonomically damaged and shifted left wing, while ignoring the shallow chord membrane on the completely articulated and pristine right wing. These authors did not realize the left ulna and radius had drifted posteriorly during taphonomy taking that portion of the wing membrane with them. That drift also produced the illusion of a single uropatagium stretched between the lateral pedal digits with no contact to the tail. This fantasy anatomy is different from all other pterosaurs and their tiny tanystropheid relatives (Cosesaurus, Sharovipteryx), all of which had separate uropatagia trailing each hind limb. 

See: https://reptileevolution.com/pterosaur-wings.htm and https://reptileevolution.com/pterodactylus-vienna.htm and https://reptileevolution.com/sordes.htm. 

5. The anurognathid anterior eyeball hypothesis
Bennett 2007 misidentified a maxilla, labeling it a giant scleral ring in the SMNS 81928 specimen he mistakenly attributed to the holotype Anurognathus, a pterosaur known since the 1920s with a small eyeball in the traditional location, in the back half of the skull. Bennett’s mistake led to several other skull and palate identification errors as he tried to accommodate his initial error with invented anatomy. A later, more precise tracing (see link below) located both scleral rings in their typical place, in the back half of the skull. The rest of the fragile skull was interpreted with a typical anurognathid morphology – with the exception that the skull was much wider than tall. Since then several similar ‘flat-head’ anurognathids have been described, but hobbled by interpretation errors following Bennett’s blueprint rather than the data.

See: https://reptileevolution.com/anurognathus-SMNS.htm  and 

https://reptileevolution.com/vesperopterylus.htm

6 and 7. The allometric archosaur growth hypothesis
Several pterosaur embryos are now known. They all have adult proportions and are hypothesized to have been able to fly shortly after hatching. Several ontogenetic series are known for Pterodaustro, Zhejiangopterus, Skiphosoura and one species of Rhamphorhynchus. The embryos, hatchlings, juveniles and adults had identical scores in phylogenetic analysis. A long rostrum and small orbit identical to adult taxa were present. This data demonstrates an isometric growth strategy beginning with a late-surviving tanystropheid ancestor, Huehuecuetzpalli, a non-squamate lepidosaur. Related taxa with a shorter rostrum and large orbit nest at basal nodes, representing phylogenetically miniaturized transitional taxa. See #8 below.

See: https://www.researchgate.net/publication/328388674_First_juvenile_Rhamphorhynchus_recovered_by_phylogenetic_analysis

See: https://pterosaurheresies.wordpress.com/2015/12/15/pterodaustro-isometric-growth-series/

http://www.reptileevolution.com/pterodaustro-embryo.htm

http://www.reptileevolution.com/ivpp-embryo.htm

http://www.reptileevolution.com/jzmp-embryo.htm

By contrast, the allometric growth strategy found in young dinosaurs (including birds) crocodylomorphs and mammals was mistakenly applied to pterosaurs by workers who ignored the data. Workers have long considered pterosaurs to be archosaurs close to dinosaurs and the basal bipedal crocodylomorph archosaur, Scleromochlus. In counterpoint, Peters (2007) added traditionally omitted taxa and recovered tanystropheids (including pterosaurs) with Huehuecuetzpalli, a non-squamate, non-sphenodontid lepidosaur with an isometric growth strategy (Reynoso 1998).

See: https://reptileevolution.com/reptile-tree.htm

Recent attempts to nest pterosaurs with lagerpetids have done so by ignoring = omitting tiny tanystropheids and Huehuecuetzpalli. Ignoring previous competing hypotheses is not the scientific method, but academic editors and referees have nevertheless approved many such manuscripts. 

After testing with traditionally omitted taxa, Lagerpeton is a sister to the more completely known Tropidosuchus, another facultative bipedal proterochampsid. Tropidosuchus and Proterochamsa have been absent from most studies that mistakenly link pterosaurs to lagerpetids. The exception is Ezcurra 2016 who intended to study only archosauromorphs and nested the pterosaur, Dimorphodon, between Vancleavea + Proterochampsa and Lagerpeton. By adding omitted taxa, the large reptile tree (LRT, 2340 taxa) recovers Vancleavea as a thalattosaur and Dimorphodon as a lepidosaur, both outside the scope of Ezcurra’s subject matter. 

As late as 2017 Vidovic and Martill used the basal quadrupedal archosauriform Euparkeria as a pterosaur outgroup taxon in phylogenetic analysis, omitting tiny tanystropheids and Huehuecuetzpalli. 

Baron (2021) wrote: “The analyses in this study support the close affinities between pterosaurs and dinosauriforms within Ornithodira; Pterosauria is recovered as the sister-taxon to Lagerpetidae. Such a result suggests that the clade Pterosauria belongs with Lagerpetidae as part of a broader Pterosauromorpha that then, with Dinosauriformes, falls within Ornithodira.” As in many prior studies, Baron did not include tiny tanystropheids from Peters 2000 nor Huehuecuetzpalli from Peters 2007. 

Adding relevant taxa resolves all phylogenetic issues and misfits. 

8. Retention of the invalidated clade ‘Pterodactyloidea.’ 
Peters 2007 added traditionally omitted in-group and out-group taxa to phylogenetic analysis. Since then more pterosaurs have been added to ‘the large pterosaur tree (LPT, 268 taxa, https://reptileevolution.com/MPUM6009-3.htm). Recovered results reveal the pterodactyloid-grade (short-to-tiny tail, short-to-tiny pedal digit 5, longer metacarpals) evolved four times by convergence. 1. Ctenochasmatidae arose from Angustinaripterus and several more primitive dorygnathid taxa. 2. Azhdarchidae arose from tiny TM 10341, another dorygnathid. 2. Hamipterus and Hongshanopterus arose from Darwinopterus. 4. Jianchangnathus and descendants include pterodactylids, cycnorhamphids, ornithocheirids, germanodactylids and their sharp rostrum descendants. Note the LPT cladogram separates the formerly united Azhdarchidae and Tapejaridae.

The LPT also included many of the Late Jurassic tiny pterosaurs otherwise omitted from analyses based on their size and presumed juvenile status. All are phylogenetically different from larger coeval taxa so do not nest with larger taxa. Instead they cluster together at several origins of (= transitions to) new clades. Thus, once again phylogenetic miniaturization is the method/strategy by which one clade transitions to another (e.g. origin of bats from small primates, origin of birds from small theropods, origin of reptiles from small reptilomorphs). This method involves serial neoteny and precocious maturity. 

See: https://reptileevolution.com/reptile-tree.htm and https://reptileevolution.com/MPUM6009-3.htm.

As an aside: Kryptodrakon (Andres et al 2014) is a Late Jurassic pterosaur described from bits and pieces. It was assembled, with some imagination, into ‘the most primitive pterodactyloid’. Notably, the bits and pieces could also be assembled, with less imagination, into a large slender dorygnathid, Sericipterus (Andres et al 2010), known from the same formation and described by the same authors. 

See: https://reptileevolution.com/dorygnathus-hauff.htm

Conclusions
These eight pterosaur observation and interpretation errors all stem from only three basic problems: 1. Ongoing taxon and citation exclusion in favor of supporting textbook stasis. 2. Lack of precision when tracing in situ elements. 3. Lack of precision in making reconstructions for comparative anatomy, which is currently misdirected = allowing untenable mismatches.

Thus the solution to these eight problems is simple: 1. Add more pertinent taxa and citations to analyses. 2. More precision in tracing in situ elements. 3. Make more precise reconstructions for comparative anatomy. This is asking for nothing more than the application of the scientific method = test all competing data and hypotheses, a practice that has been too often avoided by current studies that cherry-pick taxa and studies.

Large Pterosaur Tree (LPT, 268 taxa)
Quetzalcoatlus
Pteranodon

References  
Andres B, Clark JM and Xing X 2010. A new rhamphorhynchid pterosaur from the Upper Jurassic of Xinjiang, China, and the phylogenetic relationships of basal pterosaurs. Journal of Vertebrate Paleontology 30 (1): 163–187. doi:10.1080/02724630903409220.

Andres B, Clark J and Xu X 2014. The Earliest Pterodactyloid and the Origin of the Group. Current Biology. 24: 1011–6.  

Arthaber G 1921. Studien über Flugsaurier auf Grund der Bearbeitung des Wiener Examplares von Dorygnathus banthensis. – Denkschriften der Akademie der Wissenschaften in Wien Mathematisch-Naturwis-senschaftliche Klasse, Xcvii: 391–464.  

Baier DB, Garrity BM, Moritz S, Carney RM 2018. Alligator mississippiensis sternal and shoulder girdle mobility increase stride length during high walks. J Exp Biol. 2018 Nov 20;221(Pt 22):jeb186791. doi: 10.1242/jeb.186791. PMID: 30266782.

Baron MG 2021. The origin of pterosaurs. Earth-Science Reviews 221: 103777

Bassani F 1886. Sui Fossili e sull’ età degli schisti bituminosi triasici di Besano in Lombardia. Atti della Società Italiana di Scienze Naturali 19:15–72.

Bennett SC 1996. The phylogenetic position of the Pterosauria within the Archosauromorpha. Zoolological Journal of the Linnean Society 118: 261–308. 

Bennett SC 1997a. The arboreal leaping theory of the origin of  pterosaur flight. Historical Biology, 123(4): 265–290. 

Bennett SC 1997b. Terrestrial locomotion of pterosaurs: a reconstruction based on Pteraichnus trackways. Journal of Vertebrate Paleontology, 17: 104–113.

Bennett SC 2008. Morphological evolution of the forelimb of pterosaurs: myology and function. Pp. 127–141 in E Buffetaut and DWE Hone eds., Flugsaurier: pterosaur papers in honour of Peter Wellnhofer. Zitteliana, B28. 

Bennett SC 2012. The phylogenetic position of the Pterosauria within
the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.

Benton M 1982. The Diapsida: revolution in reptile relationships. Nature 296: 306–307.

Benton M 1984. The relationships and early evolution of the Diapsida. Symp. Zool. Soc. London 52: 575–596. 

Benton MJ 1985. Classification and phylogeny of the diapsid reptiles.
Zoological Journal of the Linnean Society 84: 97–164.

Benton MJ 1990. Origin and interrelationships of dinosaurs. In: Weishampel DB, Dobson P, Osmolska H, eds. The Dinosauria. Berkeley: University of California Press, 11–30. 

Benton MJ 1999. Scleromochlus taylori and the origin of dinosaurs and pterosaurs. Philosophical Transactions of the Royal Society London, Series B 354 1423-1446.

Bonaparte JF, Schultz CL and Soares MB 2010. Pterosauria from the Late Triassic of southern Brazil. In S. Bandyopadhyay (ed.), New Aspects of Mesozoic Biodiversity, Lecture Notes in Earth Sciences 132:63-71.

Casamiquela RM 1962. Sobre la pisada de un presunto sauria aberrante en el Liassico del Neuquen (Patagonia). Ameghiniana, 2(10): 183–186.

Chatterjee S and Templin RJ 2004. Posture, locomotion, and paleoecology of pterosaurs. The Geological Society of America Special Paper 376:1-63. 

Clark, J, Hopson J, Hernandez R, Fastovsky D and Montellano M 1998. Foot posture in a primitive pterosaur. Nature 391: 886-889. 

Da Silva JL, Pinheiro FL, Santos MAC and Garcia M 2022. De galho em galho – Lagerpetidae a origem dos pterossaurous. Paleodest Paleontologia em Destaque, v. 37, n. 77, p. 70-85, 2022. e-ISSN 1807-2550 – Sociedade Brasileira de Paleontologia.

Elgin RA, Hone DWE and Frey E 2011. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica 56 (1), 2011: 99-111. doi: 10.4202/app.2009.0145

Ellenberger P and de Villalta JF 1974. Sur la presence d’un ancêtre probable des oiseaux dans le Muschelkalk supérieure de Catalogne (Espagne). Note preliminaire. Acta Geologica Hispanica 9, 162-168.

Ellenberger P 1978. L’Origine des Oiseaux. Historique et méthodes nouvelles. Les problémes des Archaeornithes. La venue au jour de Cosesaurus aviceps (Muschelkalk supérieur) in Aspects Modernes des Recherches sur l’Evolution. In Bons, J. (ed.) Compt Ren. Coll. Montpellier 12-16 Sept. 1977. Vol. 1. Montpellier, Mém. Trav. Ecole Prat. Hautes Etudes, De l’Institut de Montpellier 4: 89-117.

Ellenberger P 1993. Cosesaurus aviceps . Vertébré aviforme du Trias Moyen de Catalogne. Étude descriptive et comparative. Mémoire Avec le concours de l’École Pratique des Hautes Etudes. Laboratorie de Paléontologie des Vertébrés. Univ. Sci. Tech. Languedoc, Montpellier (France). Pp. 1-664.

Ezcurra MD 2016.The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms.  PeerJ 4:e1778 https://doi.org/10.7717/peerj.1778

Ezcurra MD et al. (17 co-authors) 2020. Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria. Nature (2020). https://doi.org/10.1038/s41586-020-3011-4.

Foffa D et al (10 co-authors) 2022. Scleromochlus and the early evolution of Pterosauromorpha. Nature https://doi.org/10.1038/s41586-022-05284-x

Garcia MS and Müller RT 2025. Triassic pterosaur precursors of Brazil: catalog, evolutionary context, and a new hypothesis for phylogenetic relationships of Pterosauromorpha. An. Acad. Bras. Ciênc. 97 (suppl 1) https://www.scielo.br/j/aabc/a/NJjRz5dD9PymgdfwfdpSXdJ/?lang=en

Gauthier J 1986. Saurischian monophyly and the origin of birds. In: Padian K, ed. The origin of birds and the evolution of flight. Memoirs of the California Academy of Sciences, 8.San Francisco: California Academy of Sciences, 1–55.

Habib MB 2008. Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana B28: 161–168.

Hone DWE and Benton MJ 2007. An evaluation of the phylogenetic relationships of the pterosaurs to the archosauromorph reptiles. Journal of Systematic Palaeontology 5:465–469.

Hone DWE and Benton MJ 2008. Contrasting supertree and total evidence methods: the origin of the pterosaurs. Zitteliana B28:35–60.

Huene F von 1914. Beiträge zur Geshichte der Archosaurier. Geol. Palaont. Abh. NF13: 1–53.

Huxley TH 1871. Manual of the anatomy of vertebrate animals. London.

Juul L 1994. The phylogeny of basal archosaurs. Palaenotol. Afr. 31:1–38.

Kammerer CF, Nesbitt SJ, Flynn JJ, Ranivoharimanana L and Wyss AR 2020. A tiny ornithodiran archosaur from the Triassic of Madagascar and the role of miniaturization in dinosaur and pterosaur ancestry. PNAS https://doi.org/10.1073/pnas.1916631117

Kellner AWA 2003. Pterosaur phylogeny and comments on the evolutionary history of the group. Pp, 105-137 in: Buffetaut E and Mazin JM (Eds) – Evolution and palaeobiology of pterosaurs: Geo. Soc. Sp. Pub. 217.

Kellner AWA, Holgado B, Grillo O, Pretto FA, Kerber L, Pinheiro FL, Soares MB, Schultz CL, Lopes RT, Araújo O, Müller RT 2022. Reassessment of Faxinalipterus minimus, a purported Triassic pterosaur from southern Brazil with the description of a
new taxon. PeerJ 10:e13276 http://doi.org/10.7717/peerj.13276

Lockley, MG, Logue TJ, Moratalla JJ, Hunt AJ, Schultz RJ. and Robinson JW 1995. The fossil trackway Pteraichnus is pterosaurian, not crocodilian; implications for the global distribution of pterosaur tracks. Ichnos 4: 7-20. 

Mazin J-M, Hantzpergue P, Lafaurie G, and Vignaud P 1995. Des pistes de ptérosaures dans le Tithonien de Crayssac (Quercy, France). Comptes rendus de l’Academie des Sciences de Paris 321: 417-424.

Meyer H von 1847–55. Die saurier des Muschelkalkes mit rücksicht auf die saurier aus Buntem Sanstein und Keuper; pp. 1-167 in Zur fauna der Vorwelt, zweite Abteilung. Frankfurt.

Müller R 2022. The closest evolutionary relatives of pterosaurs: What the morphospace occupation of different skeletal regions tell us about lagerpetids.  The Anatomical Record. DOI:10.1002/ar.24904

Nesbitt SJ and Hone DWE 2010. An external mandibular fenestra and other archosauriform character states in basal pterosaurs. Palaeodiversity 3: 225–233

Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 292 pp.

Nopcsa FB 1923. Neubeschreibung des Trias-Pterosauriers Tribelesodon. Paläontologische Zeitschrift. 1923;5(3):161–181. doi: 10.1007/BF03160365. 

Nosotti S 2007. Tanystropheus longobardicus (Reptilia, Protorosauria: Reinterpretations of the anatomy based on new specimens from the Middle Triassic of Besano (Lombardy, Northern Italy). Memorie della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano, Vol. XXXV – Fascicolo III, pp. 1-88.

Ostrom J H 1976. Archaeopteryx and the origin of birds. Biological Journal of the Linnean Society. 8 (2):91–182.

Padian K 1983a. Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum. Postilla, 189: 1–44. 

Padian K 1983b. A functional analysis of flying and walking in pterosaurs. Paelobiology, 9: 218–239.

Padian K 1984. The origin of pterosaurs. Pp. 163–168 in Reif W-Eand Westphal F (eds) Proceedings of the Third Symposiaum on Mesozoic Terestrial Ecoystems. Short Papers, Tübingen.

Padian K 1997. Pterosauromorpha. In: Currie PJ, Padian K, editors. Encyclopedia of Dinosaurs. San Diego: Academic Press; 1997. pp. 617–618.

Padian K 2003. Pterosaur stance and gait and the interpretation of trackways. Ichnos, 10: 115–126. 

Padian K 2020. Closest relatives found for pterosaurs, the first flying vertebrates.
Nature News and views (2020) https://www.nature.com/articles/d41586-020-03420-z

Paul GS 2022. The Princeton Field Guide to Pterosaurs. Princeton Field Guides. Online.

Peters D 1995. Wing Shape in Pterosaurs. Nature 374: 315–316.   

Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.

Peters D 2000b. A redescription of four prolacertiform genera and implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 293-336.   

Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. Historical Biology 15: 277-301   

Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-1330.

Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605

Peters D 2018a. (preprint) Cosesaurus aviceps, Sharovipteryx mirabilis and Longisquama insignis Reinterpreted. https://www.researchgate.net/publication/328388115_Cosesaurus_aviceps_Sharovipteryx_mirabilis_and_Longisquama_insignis_Reinterpreted

Peters D 2018b. (preprint) A new lepidosaur clade: the Tritosauria. https://www.researchgate.net/publication/328388754_A_new_lepidosaur_clade_the_Tritosauria

Peyer B 1931. Tanystropheus longobardicus Bass sp. Die Triasfauna der Tessiner Kalkalpen. Abhandlungen Schweizerische Paläontologie Gesellschaft 50:5-110.

Reynoso, V.-H. 1998. Huehuecuetzpalli mixtecus gen. et sp. nov: a basal squamate (Reptilia) from the Early Cretaceous of Tepexi de Rodríguez, Central México. Philosophical Transactions of the Royal Society, London B 353: 477–500.

Romer AS 1956. Osteology of the Reptiles. University of Chicago Press xxi–772. 

Sanz JL and López-Martinez N 1984. The prolacertid lepidosaurian Cosesaurus aviceps Ellenberger & Villalta, a claimed ‘protoavian’ from the Middle Triassic of Spain. Géobios 17: 747-753.

Sato K, Sakamoto K, Watanuki Y, Takahashi A, Katsumata N, et al. 2009. Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs. PLoS ONE 4: e5400.

Sereno PC 1991. Basal archosaurs: phylogenetic relationships and functional implications. Sociep of Vertebrate Paleontology memoir 2, Journal of Vertebrate Paleontology, 11 (Supplement to #4): 1-53.

Sharov AG 1971. New flying reptiles from the Mesozoic of Kazakhstan and Kirghizia. – Transactions of the Paleontological Institute, Akademia Nauk, USSR, Moscow, 130: 104–113 [in Russian].  

Spiekman SNF, Fraser NC, Scheyer TM 2021. A new phylogenetic hypothesis of Tanystropheidae (Diapsida, Archosauromorpha) and other “protorosaurs”, and its implications for the early evolution of stem archosaurs. PeerJ. 2021 May 3;9:e11143. doi: 10.7717/peerj.11143. PMID: 33986981; PMCID: PMC8101476.

Spiekman SNF et al (12 co-authors) 2025. Triassic diapsid shows early diversification of skin apprendages in reptiles. Nature https://doi.org/10.1038/s41586-025-09167-9

Stokes WL 1957. Pterodactyl tracks from the Morrison Formation. Journal of Palaeontology 31: 952-954. 

Tschanz K 1988. Allometry and heterochrony in the growth of the neck of Triassic prolacertiform reptiles. Palaeontology 31: 997–1011. 

Witton MP 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana B28: 143–159. 

Witton MP and Naish D 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS ONE 3: e2271. 

Witton MP and Habib MB 2010. On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982. https://doi.org/10.1371/journal.pone.0013982

Unwin DM 1989. A predictive method for the identification of vertebrate ichnites and its application to pterosaur tracks. In Gillette, D. D. and Lockley, M. G.  (eds.) Dinosaur Tracks and Traces. Cambridge University Press, Cambridge. 259-274. Unwin DM 1997. Pterosaur tracks and the terrestrial ability of pterosaurs. Lethaia 29: 373-386.

Unwin DM and Bakhurina NN 1994. Sordes pilosus and the nature of the pterosaur flight apparatus. Nature 371: 62-64.

Unwin DM Alifanov VR and Benton MJ 2000. Enigmatic small reptiles from the Middle-Late Triassic of Kirgizstan. In: Benton MJ, Kurochkin EN, Shishkin MA, Unwin DM, editors. The Age of Dinosaurs in Russia and Mongolia. Cambridge: Cambridge University Press; 2000. pp. 140–159. 

Unwin DM 2003. On the phylogeny and evolutionary history of pterosaurs. Pp. 139-190 in: Buffetaut E and Mazin JM (Eds) – Evolution and Palaeobiology of Pterosaurs. Geo. Soc. Sp. Pub. 217.

Vidovic SU and Martill DM 2017. The taxonomy and phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus’ (Wagner, 1851). From: Hone DWE., Witton MP and Martill DM (eds) New Perspectives on Pterosaur Palaeobiology. Geological Society, London, Special Publications, 455, https://doi.org/10.1144/SP455.12

Wellnhoffer P 1991.  The Illustrated Encyclopedia of Pterosaurs. London: Salamander. 192 pp.

Wild R 1973. Die Triasfauna der Tessiner Kalkalpen XXIII. Tanystropheus longobardicus(Bassani) (Neue Ergebnisse). – Schweizerische Paläontologische Abhandlungen 95: 1-16.

Wild R 1978. Die Flugsaurier (Reptilia, Pterosauria) aus der Oberen Trias von Cene bei Bergamo, Italien. Bolletino della Societa Paleontologica Italiana 17(2): 176–256.

Wild R 1983. Über die Ursprung der Flugsaurier.  Weltenberger Akademie, Erwin Rutte-Festschrift, pp. 231–38. 

Wild R 1984.  A new pterosaur (Reptilia, Pterosauria) from the Upper Triassic (Norian) of Friuli, Italy. Gortania Mus Friulano Stor Nat 5: 45-62.

Xing L, O’Connor JK,; Schmitz L, Chiappe LM, McKellar RC, Yi Q and Li G 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579 (7798): 245–249.

Web pages of interest

Bird and pterosaur comparisons: Witton and Habib 2010

What exactly IS a pterosaur? – part 3 of 3

Euparkeria and the origin of birds… and pterosaurs

A Bipedal AND Quadrupedal Pterosaur Trackway

Source: https://pterosaurheresies.wordpress.com/2026/05/30/stasis-misdirection-and-taxon-exclusion-in-recent-pterosaur-studies/