Let’s pop those Nemicolopterus myths

Many myths surround the tiny pterosaur
Nemicolopterus (Figs 1–5). Many workers share blame, all based on 1) taxon exclusion 2) lack of accurate reconstruction, 3) refusal to accept that pterosaurs are lepidosaurs and 4) suppression of the phylogenetic miniaturization hypothesis in pterosaur phylogeny.

In other words: blame based on outdated thinking still taught at the university level.

Nemicolopterus was described as
the smallest pterosaur (Wang et al. 2008). This is false. The unnamed n6 (B St 1967 I 276) specimen of Wellnhofer 1970, Fig 2) remains the smallest pterosaur outside of an eggshell.

And n6 is gravid.

Other workers have failed
to provide a reconstruction (as in figures 1–5). When enlarged (Fig 3) Nemicolopterus shares a long list of traits with Shenzhoupterus, a taxon ignored by all prior workers, perhaps because when first published no one realized the sternal complex was semi-hidden behind the skull, something I learned while in China during the good years.

You can read that paper online here.

According to Wikipedia – Nemicolopterus
“Wang et al. (2008), who originally described the specimen, concluded that it was immature, citing the amount of bone fusion and the ossification of the toes, gastralia, and sternum as indicating that it was a sub-adult rather than a hatchling. However, Darren Naish argued on his popular weblog that, due to the hypothesis that pterosaurs were highly precocial, bone fusion and ossification could have occurred very early in life, and that Nemicolopterus might in fact be a hatchling individual of the genus Sinopterus.”

Good to see that ‘popular weblogs’ are cited. You might remember, in 2012 Naish sought to suppress readership at ReptileEvolution.com.

When Shenzhoupterus is correctly reconstructed and scored then added to analysis, Nemicolopterus nests with Shenzhoupterus, close to Sinopterus, but not closer to Sinopterus.

According to Wikipedia – Nemicolopterus,
“A [Pégas et al] 2023 revision of Sinopterus concluded that it was impossible to assign the Nemicolopterus specimen to either Sinopterus or the new genus Huaxiadraco, and it was therefore considered an indeterminate sinopterine.”

That’s because Nemicolopterus is a shenzhoupterid, not a sinopterine. Don’t accept ‘impossible’ and ‘indeterminate‘. Add taxa until you find a close match. IMHO we’re at that ‘critical mass’ stage now. That means very few new outliers are going to be discovered in the vertebrate fossil record. Every new taxon will be related to something else already in the LRT and/or LPT.

The Jurassic-Cretaceous filter
As noted earlier, and widely recognized, but sometimes forgotten, many medium-to-large pterosaurs did not make it through the end-Jurassic extinction event. Only the relatively tiny pterosaurs, like Nemicolopterus, survived to the Early Cretaceous. Thereafter these taxa repopuluated the planet with larger and larger descendant pterosaurs, like Shenzhoupterus.

Nemicolopterus crypticus
IVPP V-14377 (Wang et al. 2008) ~120 mya, Aptian, Early Cretaceous, ~25 cm wingspan, is a very tiny pterosaur, but to the credit of its describers they considered it a sub-adult rather than a hatchling. Derived from a sister to the B St 1878 VI 1 specimen (Fig 5). Nemicolopterus phylogenetically preceded the much larger Shenzhoupterus and Sinopterus.

The small size of Nemicolopterus is yet another example of size reduction during a morphological change from larger taxa (eg Germanodactylus cristatus) to another different large clade of taxa (eg Shenzhoupterus).

Shenzhoupterus sanyainus
(Ji, Zhang and Lu 2023, Early Cretaceous, China, 80cm long) nests as a sister to the genus holotype, Shenzhoupterus chaoyangenis, with distinct proportions including feet no larger than the smaller holotype. Note the longer tibia and metacarpus. The pelvis is smaller on the larger species.

References
Andres B and Langston W Jr 2021. Morphology and taxonomy of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea). Journal of Vertebrate Paleontology Memoir 19 41(2):46–202.
Campos HBN 2021. A new azhdarchoid pterosaur from the Late Cretaceous Javelina Formationof Texas. Biologia doi:10.1007/s11756-021-00841-7
Ji S, Zhang L and Lu F 2023. A new species of chaoyangopterid pterosaur from the Early Cretaceous in western Liaoning, Peoples Republic of China. Acta Geoogica Sinica 97(6): 1–18 in Chinese with an English abstract.
Lü J, Unwin DM, Xu L and Zhang X 2008. A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften 95 (9): online (preprint). doi:10.1007/s00114-008-0397-5. PMID 18509616.
Naish D, Witton MP and Martin-Silverstone E 2021. Powered flight in hatchling pterosaurs: evidence from wing form and bone strength. Sci Rep 11, 13130 (2021). https://doi.org/10.1038/s41598-021-92499-z
Pêgas RV et al (4 co-authors) 2023. A taxonomic revision of the Sinopterus complex (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota, with the new genus Huaxiadraco. PeerJ. 11: e14829.
Vullo R, Garcia G, Godefroit P, Cincotta A, and Valentin X 2018. Mistralazhdarcho maggii, gen. et sp. nov., a new azhdarchid pterosaur from the Upper Cretaceous of southeastern France. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1502670.
Wang X, Kellner AWA, Zhou Z and Campos DA 2008. Discovery of a rare arboreal forest-dwelling flying reptile (Pterosauria, Pterodactyloidea) from China. Proceedings of the National Academy of Sciences, 106(6): 1983–1987. doi:10.1073/pnas.0707728105
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Nemicolopterus
wiki/Mistralazhdarcho
wiki/Shenzhoupterus
wiki/Javelinadactylus = Wellnopterus

Several pterosaur myths get a boost from Naish, Witton and Martin-Silverstone 2021

Where the heck is the sternal complex in Shenzhoupterus?